hello-algo/chapter_stack_and_queue/deque/index.html
2023-10-14 22:15:01 +08:00

6842 lines
No EOL
813 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!doctype html>
<html lang="zh" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta name="description" content="动画图解、一键运行的数据结构与算法教程">
<meta name="author" content="Krahets">
<link rel="canonical" href="https://www.hello-algo.com/chapter_stack_and_queue/deque/">
<link rel="prev" href="../queue/">
<link rel="next" href="../summary/">
<link rel="icon" href="../../assets/images/favicon.png">
<meta name="generator" content="mkdocs-1.5.3, mkdocs-material-9.4.1">
<title>5.3   双向队列 - Hello 算法</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.72749a73.min.css">
<link rel="stylesheet" href="../../assets/stylesheets/palette.a5377069.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Noto+Sans+SC:300,300i,400,400i,700,700i%7CFira+Code:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"Noto Sans SC";--md-code-font:"Fira Code"}</style>
<link rel="stylesheet" href="../../stylesheets/extra.css">
<script>__md_scope=new URL("../..",location),__md_hash=e=>[...e].reduce((e,_)=>(e<<5)-e+_.charCodeAt(0),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
<link href="../../assets/stylesheets/glightbox.min.css" rel="stylesheet"/><style>
html.glightbox-open { overflow: initial; height: 100%; }
.gslide-title { margin-top: 0px; user-select: text; }
.gslide-desc { color: #666; user-select: text; }
.gslide-image img { background: white; }
.gscrollbar-fixer { padding-right: 15px; }
.gdesc-inner { font-size: 0.75rem; }
body[data-md-color-scheme="slate"] .gdesc-inner { background: var(--md-default-bg-color);}
body[data-md-color-scheme="slate"] .gslide-title { color: var(--md-default-fg-color);}
body[data-md-color-scheme="slate"] .gslide-desc { color: var(--md-default-fg-color);}
</style> <script src="../../assets/javascripts/glightbox.min.js"></script></head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="white" data-md-color-accent="indigo">
<script>var palette=__md_get("__palette");if(palette&&"object"==typeof palette.color)for(var key of Object.keys(palette.color))document.body.setAttribute("data-md-color-"+key,palette.color[key])</script>
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#53" class="md-skip">
跳转至
</a>
</div>
<div data-md-component="announce">
</div>
<header class="md-header md-header--shadow" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="页眉">
<a href="../.." title="Hello 算法" class="md-header__button md-logo" aria-label="Hello 算法" data-md-component="logo">
<img src="../../assets/images/logo.png" alt="logo">
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3V6m0 5h18v2H3v-2m0 5h18v2H3v-2Z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
Hello 算法
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
5.3 &nbsp; 双向队列
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="" data-md-color-scheme="default" data-md-color-primary="white" data-md-color-accent="indigo" aria-label="Switch to dark mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Switch to dark mode" for="__palette_2" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M7.5 2c-1.79 1.15-3 3.18-3 5.5s1.21 4.35 3.03 5.5C4.46 13 2 10.54 2 7.5A5.5 5.5 0 0 1 7.5 2m11.57 1.5 1.43 1.43L4.93 20.5 3.5 19.07 19.07 3.5m-6.18 2.43L11.41 5 9.97 6l.42-1.7L9 3.24l1.75-.12.58-1.65L12 3.1l1.73.03-1.35 1.13.51 1.67m-3.3 3.61-1.16-.73-1.12.78.34-1.32-1.09-.83 1.36-.09.45-1.29.51 1.27 1.36.03-1.05.87.4 1.31M19 13.5a5.5 5.5 0 0 1-5.5 5.5c-1.22 0-2.35-.4-3.26-1.07l7.69-7.69c.67.91 1.07 2.04 1.07 3.26m-4.4 6.58 2.77-1.15-.24 3.35-2.53-2.2m4.33-2.7 1.15-2.77 2.2 2.54-3.35.23m1.15-4.96-1.14-2.78 3.34.24-2.2 2.54M9.63 18.93l2.77 1.15-2.53 2.19-.24-3.34Z"/></svg>
</label>
<input class="md-option" data-md-color-media="" data-md-color-scheme="slate" data-md-color-primary="grey" data-md-color-accent="indigo" aria-label="Switch to light mode" type="radio" name="__palette" id="__palette_2">
<label class="md-header__button md-icon" title="Switch to light mode" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M7.5 2c-1.79 1.15-3 3.18-3 5.5s1.21 4.35 3.03 5.5C4.46 13 2 10.54 2 7.5A5.5 5.5 0 0 1 7.5 2m11.57 1.5 1.43 1.43L4.93 20.5 3.5 19.07 19.07 3.5m-6.18 2.43L11.41 5 9.97 6l.42-1.7L9 3.24l1.75-.12.58-1.65L12 3.1l1.73.03-1.35 1.13.51 1.67m-3.3 3.61-1.16-.73-1.12.78.34-1.32-1.09-.83 1.36-.09.45-1.29.51 1.27 1.36.03-1.05.87.4 1.31M19 13.5a5.5 5.5 0 0 1-5.5 5.5c-1.22 0-2.35-.4-3.26-1.07l7.69-7.69c.67.91 1.07 2.04 1.07 3.26m-4.4 6.58 2.77-1.15-.24 3.35-2.53-2.2m4.33-2.7 1.15-2.77 2.2 2.54-3.35.23m1.15-4.96-1.14-2.78 3.34.24-2.2 2.54M9.63 18.93l2.77 1.15-2.53 2.19-.24-3.34Z"/></svg>
</label>
</form>
<div class="md-header__option">
<div class="md-select">
<button class="md-header__button md-icon" aria-label="选择当前语言">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m12.87 15.07-2.54-2.51.03-.03A17.52 17.52 0 0 0 14.07 6H17V4h-7V2H8v2H1v2h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04M18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12m-2.62 7 1.62-4.33L19.12 17h-3.24Z"/></svg>
</button>
<div class="md-select__inner">
<ul class="md-select__list">
<li class="md-select__item">
<a href="/" hreflang="zh" class="md-select__link">
中文
</a>
</li>
</ul>
</div>
</div>
</div>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="搜索" placeholder="搜索" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.516 6.516 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5Z"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</label>
<nav class="md-search__options" aria-label="查找">
<a href="javascript:void(0)" class="md-search__icon md-icon" title="分享" aria-label="分享" data-clipboard data-clipboard-text="" data-md-component="search-share" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18 16.08c-.76 0-1.44.3-1.96.77L8.91 12.7c.05-.23.09-.46.09-.7 0-.24-.04-.47-.09-.7l7.05-4.11c.54.5 1.25.81 2.04.81a3 3 0 0 0 3-3 3 3 0 0 0-3-3 3 3 0 0 0-3 3c0 .24.04.47.09.7L8.04 9.81C7.5 9.31 6.79 9 6 9a3 3 0 0 0-3 3 3 3 0 0 0 3 3c.79 0 1.5-.31 2.04-.81l7.12 4.15c-.05.21-.08.43-.08.66 0 1.61 1.31 2.91 2.92 2.91 1.61 0 2.92-1.3 2.92-2.91A2.92 2.92 0 0 0 18 16.08Z"/></svg>
</a>
<button type="reset" class="md-search__icon md-icon" title="清空当前内容" aria-label="清空当前内容" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41Z"/></svg>
</button>
</nav>
<div class="md-search__suggest" data-md-component="search-suggest"></div>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
正在初始化搜索引擎
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
<div class="md-header__source">
<a href="https://github.com/krahets/hello-algo" title="前往仓库" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg>
</div>
<div class="md-source__repository">
krahets/hello-algo
</div>
</a>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary" aria-label="导航栏" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../.." title="Hello 算法" class="md-nav__button md-logo" aria-label="Hello 算法" data-md-component="logo">
<img src="../../assets/images/logo.png" alt="logo">
</a>
Hello 算法
</label>
<div class="md-nav__source">
<a href="https://github.com/krahets/hello-algo" title="前往仓库" class="md-source" data-md-component="source">
<div class="md-source__icon md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg>
</div>
<div class="md-source__repository">
krahets/hello-algo
</div>
</a>
</div>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_1" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_preface/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M21 4H3a2 2 0 0 0-2 2v13a2 2 0 0 0 2 2h18a2 2 0 0 0 2-2V6a2 2 0 0 0-2-2M3 19V6h8v13H3m18 0h-8V6h8v13m-7-9.5h6V11h-6V9.5m0 2.5h6v1.5h-6V12m0 2.5h6V16h-6v-1.5Z"/></svg>
<span class="md-ellipsis">
第 0 章 &nbsp; 前言
</span>
</a>
<label class="md-nav__link " for="__nav_1">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_1_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_1">
<span class="md-nav__icon md-icon"></span>
第 0 章 &nbsp; 前言
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_preface/about_the_book/" class="md-nav__link">
<span class="md-ellipsis">
0.1 &nbsp; 关于本书
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_preface/suggestions/" class="md-nav__link">
<span class="md-ellipsis">
0.2 &nbsp; 如何使用本书
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_preface/summary/" class="md-nav__link">
<span class="md-ellipsis">
0.3 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_2" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_introduction/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 3H5c-1.1 0-2 .9-2 2v14c0 1.1.9 2 2 2h14c1.1 0 2-.9 2-2V5c0-1.1-.9-2-2-2m0 16H5V5h14v14M6.2 7.7h5v1.5h-5V7.7m6.8 8.1h5v1.5h-5v-1.5m0-2.6h5v1.5h-5v-1.5M8 18h1.5v-2h2v-1.5h-2v-2H8v2H6V16h2v2m6.1-7.1 1.4-1.4 1.4 1.4 1.1-1-1.4-1.4L18 7.1 16.9 6l-1.4 1.4L14.1 6 13 7.1l1.4 1.4L13 9.9l1.1 1Z"/></svg>
<span class="md-ellipsis">
第 1 章 &nbsp; 初识算法
</span>
</a>
<label class="md-nav__link " for="__nav_2">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_2">
<span class="md-nav__icon md-icon"></span>
第 1 章 &nbsp; 初识算法
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_introduction/algorithms_are_everywhere/" class="md-nav__link">
<span class="md-ellipsis">
1.1 &nbsp; 算法无处不在
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_introduction/what_is_dsa/" class="md-nav__link">
<span class="md-ellipsis">
1.2 &nbsp; 算法是什么
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_introduction/summary/" class="md-nav__link">
<span class="md-ellipsis">
1.3 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_computational_complexity/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M6 2h12v6l-4 4 4 4v6H6v-6l4-4-4-4V2m10 14.5-4-4-4 4V20h8v-3.5m-4-5 4-4V4H8v3.5l4 4M10 6h4v.75l-2 2-2-2V6Z"/></svg>
<span class="md-ellipsis">
第 2 章 &nbsp; 复杂度分析
</span>
</a>
<label class="md-nav__link " for="__nav_3">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3">
<span class="md-nav__icon md-icon"></span>
第 2 章 &nbsp; 复杂度分析
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_computational_complexity/performance_evaluation/" class="md-nav__link">
<span class="md-ellipsis">
2.1 &nbsp; 算法效率评估
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_computational_complexity/iteration_and_recursion/" class="md-nav__link">
<span class="md-ellipsis">
2.2 &nbsp; 迭代与递归
</span>
<span class="md-status md-status--new" title="最近添加">
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_computational_complexity/time_complexity/" class="md-nav__link">
<span class="md-ellipsis">
2.3 &nbsp; 时间复杂度
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_computational_complexity/space_complexity/" class="md-nav__link">
<span class="md-ellipsis">
2.4 &nbsp; 空间复杂度
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_computational_complexity/summary/" class="md-nav__link">
<span class="md-ellipsis">
2.5 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_data_structure/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M11 13.5v8H3v-8h8m-2 2H5v4h4v-4M12 2l5.5 9h-11L12 2m0 3.86L10.08 9h3.84L12 5.86M17.5 13c2.5 0 4.5 2 4.5 4.5S20 22 17.5 22 13 20 13 17.5s2-4.5 4.5-4.5m0 2a2.5 2.5 0 0 0-2.5 2.5 2.5 2.5 0 0 0 2.5 2.5 2.5 2.5 0 0 0 2.5-2.5 2.5 2.5 0 0 0-2.5-2.5Z"/></svg>
<span class="md-ellipsis">
第 3 章 &nbsp; 数据结构
</span>
</a>
<label class="md-nav__link " for="__nav_4">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_4_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4">
<span class="md-nav__icon md-icon"></span>
第 3 章 &nbsp; 数据结构
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_data_structure/classification_of_data_structure/" class="md-nav__link">
<span class="md-ellipsis">
3.1 &nbsp; 数据结构分类
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_data_structure/basic_data_types/" class="md-nav__link">
<span class="md-ellipsis">
3.2 &nbsp; 基本数据类型
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_data_structure/number_encoding/" class="md-nav__link">
<span class="md-ellipsis">
3.3 &nbsp; 数字编码 *
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_data_structure/character_encoding/" class="md-nav__link">
<span class="md-ellipsis">
3.4 &nbsp; 字符编码 *
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_data_structure/summary/" class="md-nav__link">
<span class="md-ellipsis">
3.5 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_5" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_array_and_linkedlist/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 5v14h17V5H3m4 2v2H5V7h2m-2 6v-2h2v2H5m0 2h2v2H5v-2m13 2H9v-2h9v2m0-4H9v-2h9v2m0-4H9V7h9v2Z"/></svg>
<span class="md-ellipsis">
第 4 章 &nbsp; 数组与链表
</span>
</a>
<label class="md-nav__link " for="__nav_5">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_5_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_5">
<span class="md-nav__icon md-icon"></span>
第 4 章 &nbsp; 数组与链表
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_array_and_linkedlist/array/" class="md-nav__link">
<span class="md-ellipsis">
4.1 &nbsp; 数组
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_array_and_linkedlist/linked_list/" class="md-nav__link">
<span class="md-ellipsis">
4.2 &nbsp; 链表
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_array_and_linkedlist/list/" class="md-nav__link">
<span class="md-ellipsis">
4.3 &nbsp; 列表
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_array_and_linkedlist/summary/" class="md-nav__link">
<span class="md-ellipsis">
4.4 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_6" checked>
<div class="md-nav__link md-nav__container">
<a href="../" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M17.36 20.2v-5.38h1.79V22H3v-7.18h1.8v5.38h12.56M6.77 14.32l.37-1.76 8.79 1.85-.37 1.76-8.79-1.85m1.16-4.21.76-1.61 8.14 3.78-.76 1.62-8.14-3.79m2.26-3.99 1.15-1.38 6.9 5.76-1.15 1.37-6.9-5.75m4.45-4.25L20 9.08l-1.44 1.07-5.36-7.21 1.44-1.07M6.59 18.41v-1.8h8.98v1.8H6.59Z"/></svg>
<span class="md-ellipsis">
第 5 章 &nbsp; 栈与队列
</span>
</a>
<label class="md-nav__link " for="__nav_6">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_6_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_6">
<span class="md-nav__icon md-icon"></span>
第 5 章 &nbsp; 栈与队列
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../stack/" class="md-nav__link">
<span class="md-ellipsis">
5.1 &nbsp;
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../queue/" class="md-nav__link">
<span class="md-ellipsis">
5.2 &nbsp; 队列
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<label class="md-nav__link md-nav__link--active" for="__toc">
<span class="md-ellipsis">
5.3 &nbsp; 双向队列
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
5.3 &nbsp; 双向队列
</span>
</a>
<nav class="md-nav md-nav--secondary" aria-label="目录">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
目录
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#531" class="md-nav__link">
5.3.1 &nbsp; 双向队列常用操作
</a>
</li>
<li class="md-nav__item">
<a href="#532" class="md-nav__link">
5.3.2 &nbsp; 双向队列实现 *
</a>
<nav class="md-nav" aria-label="5.3.2   双向队列实现 *">
<ul class="md-nav__list">
<li class="md-nav__item">
<a href="#1" class="md-nav__link">
1. &nbsp; 基于双向链表的实现
</a>
</li>
<li class="md-nav__item">
<a href="#2" class="md-nav__link">
2. &nbsp; 基于数组的实现
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="#533" class="md-nav__link">
5.3.3 &nbsp; 双向队列应用
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../summary/" class="md-nav__link">
<span class="md-ellipsis">
5.4 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_7" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_hashing/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19.3 17.89c1.32-2.1.7-4.89-1.41-6.21a4.52 4.52 0 0 0-6.21 1.41C10.36 15.2 11 18 13.09 19.3c1.47.92 3.33.92 4.8 0L21 22.39 22.39 21l-3.09-3.11m-2-.62c-.98.98-2.56.97-3.54 0-.97-.98-.97-2.56.01-3.54.97-.97 2.55-.97 3.53 0 .96.99.95 2.57-.03 3.54h.03M19 4H5a2 2 0 0 0-2 2v12a2 2 0 0 0 2 2h5.81a6.3 6.3 0 0 1-1.31-2H5v-4h4.18c.16-.71.43-1.39.82-2H5V8h6v2.81a6.3 6.3 0 0 1 2-1.31V8h6v2a6.499 6.499 0 0 1 2 2V6a2 2 0 0 0-2-2Z"/></svg>
<span class="md-ellipsis">
第 6 章 &nbsp; 哈希表
</span>
</a>
<label class="md-nav__link " for="__nav_7">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_7_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_7">
<span class="md-nav__icon md-icon"></span>
第 6 章 &nbsp; 哈希表
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_hashing/hash_map/" class="md-nav__link">
<span class="md-ellipsis">
6.1 &nbsp; 哈希表
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_hashing/hash_collision/" class="md-nav__link">
<span class="md-ellipsis">
6.2 &nbsp; 哈希冲突
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_hashing/hash_algorithm/" class="md-nav__link">
<span class="md-ellipsis">
6.3 &nbsp; 哈希算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_hashing/summary/" class="md-nav__link">
<span class="md-ellipsis">
6.4 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_8" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_tree/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19.5 17c-.14 0-.26 0-.39.04L17.5 13.8c.45-.45.75-1.09.75-1.8a2.5 2.5 0 0 0-2.5-2.5c-.14 0-.25 0-.4.04L13.74 6.3c.47-.46.76-1.09.76-1.8a2.5 2.5 0 0 0-5 0c0 .7.29 1.34.76 1.79L8.65 9.54c-.15-.04-.26-.04-.4-.04a2.5 2.5 0 0 0-2.5 2.5c0 .71.29 1.34.75 1.79l-1.61 3.25C4.76 17 4.64 17 4.5 17a2.5 2.5 0 0 0 0 5A2.5 2.5 0 0 0 7 19.5c0-.7-.29-1.34-.76-1.79l1.62-3.25c.14.04.26.04.39.04s.25 0 .38-.04l1.63 3.25c-.47.45-.76 1.09-.76 1.79a2.5 2.5 0 0 0 5 0A2.5 2.5 0 0 0 12 17c-.13 0-.26 0-.39.04L10 13.8c.45-.45.75-1.09.75-1.8 0-.7-.29-1.33-.75-1.79l1.61-3.25c.13.04.26.04.39.04s.26 0 .39-.04L14 10.21a2.5 2.5 0 0 0 1.75 4.29c.13 0 .25 0 .38-.04l1.63 3.25c-.47.45-.76 1.09-.76 1.79a2.5 2.5 0 0 0 5 0 2.5 2.5 0 0 0-2.5-2.5m-15 3.5c-.55 0-1-.45-1-1s.45-1 1-1 1 .45 1 1-.45 1-1 1m8.5-1c0 .55-.45 1-1 1s-1-.45-1-1 .45-1 1-1 1 .45 1 1M7.25 12c0-.55.45-1 1-1s1 .45 1 1-.45 1-1 1-1-.45-1-1M11 4.5c0-.55.45-1 1-1s1 .45 1 1-.45 1-1 1-1-.45-1-1m3.75 7.5c0-.55.45-1 1-1s1 .45 1 1-.45 1-1 1-1-.45-1-1m4.75 8.5c-.55 0-1-.45-1-1s.45-1 1-1 1 .45 1 1-.45 1-1 1Z"/></svg>
<span class="md-ellipsis">
第 7 章 &nbsp;
</span>
</a>
<label class="md-nav__link " for="__nav_8">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_8_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_8">
<span class="md-nav__icon md-icon"></span>
第 7 章 &nbsp;
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_tree/binary_tree/" class="md-nav__link">
<span class="md-ellipsis">
7.1 &nbsp; 二叉树
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_tree/binary_tree_traversal/" class="md-nav__link">
<span class="md-ellipsis">
7.2 &nbsp; 二叉树遍历
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_tree/array_representation_of_tree/" class="md-nav__link">
<span class="md-ellipsis">
7.3 &nbsp; 二叉树数组表示
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_tree/binary_search_tree/" class="md-nav__link">
<span class="md-ellipsis">
7.4 &nbsp; 二叉搜索树
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_tree/avl_tree/" class="md-nav__link">
<span class="md-ellipsis">
7.5 &nbsp; AVL 树 *
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_tree/summary/" class="md-nav__link">
<span class="md-ellipsis">
7.6 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_9" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_heap/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 1a2.5 2.5 0 0 0-2.5 2.5A2.5 2.5 0 0 0 11 5.79V7H7a2 2 0 0 0-2 2v.71A2.5 2.5 0 0 0 3.5 12 2.5 2.5 0 0 0 5 14.29V15H4a2 2 0 0 0-2 2v1.21A2.5 2.5 0 0 0 .5 20.5 2.5 2.5 0 0 0 3 23a2.5 2.5 0 0 0 2.5-2.5A2.5 2.5 0 0 0 4 18.21V17h4v1.21a2.5 2.5 0 0 0-1.5 2.29A2.5 2.5 0 0 0 9 23a2.5 2.5 0 0 0 2.5-2.5 2.5 2.5 0 0 0-1.5-2.29V17a2 2 0 0 0-2-2H7v-.71A2.5 2.5 0 0 0 8.5 12 2.5 2.5 0 0 0 7 9.71V9h10v.71A2.5 2.5 0 0 0 15.5 12a2.5 2.5 0 0 0 1.5 2.29V15h-1a2 2 0 0 0-2 2v1.21a2.5 2.5 0 0 0-1.5 2.29A2.5 2.5 0 0 0 15 23a2.5 2.5 0 0 0 2.5-2.5 2.5 2.5 0 0 0-1.5-2.29V17h4v1.21a2.5 2.5 0 0 0-1.5 2.29A2.5 2.5 0 0 0 21 23a2.5 2.5 0 0 0 2.5-2.5 2.5 2.5 0 0 0-1.5-2.29V17a2 2 0 0 0-2-2h-1v-.71A2.5 2.5 0 0 0 20.5 12 2.5 2.5 0 0 0 19 9.71V9a2 2 0 0 0-2-2h-4V5.79a2.5 2.5 0 0 0 1.5-2.29A2.5 2.5 0 0 0 12 1m0 1.5a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1M6 11a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1m12 0a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1M3 19.5a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1m6 0a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1m6 0a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1m6 0a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1Z"/></svg>
<span class="md-ellipsis">
第 8 章 &nbsp;
</span>
</a>
<label class="md-nav__link " for="__nav_9">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_9_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_9">
<span class="md-nav__icon md-icon"></span>
第 8 章 &nbsp;
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_heap/heap/" class="md-nav__link">
<span class="md-ellipsis">
8.1 &nbsp;
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_heap/build_heap/" class="md-nav__link">
<span class="md-ellipsis">
8.2 &nbsp; 建堆操作
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_heap/top_k/" class="md-nav__link">
<span class="md-ellipsis">
8.3 &nbsp; Top-K 问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_heap/summary/" class="md-nav__link">
<span class="md-ellipsis">
8.4 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_10" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_graph/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m12 5.37-.44-.06L6 14.9c.24.21.4.48.47.78h11.06c.07-.3.23-.57.47-.78l-5.56-9.59-.44.06M6.6 16.53l4.28 2.53c.29-.27.69-.43 1.12-.43.43 0 .83.16 1.12.43l4.28-2.53H6.6M12 22a1.68 1.68 0 0 1-1.68-1.68l.09-.56-4.3-2.55c-.31.36-.76.58-1.27.58a1.68 1.68 0 0 1-1.68-1.68c0-.79.53-1.45 1.26-1.64V9.36c-.83-.11-1.47-.82-1.47-1.68A1.68 1.68 0 0 1 4.63 6c.55 0 1.03.26 1.34.66l4.41-2.53-.06-.45c0-.93.75-1.68 1.68-1.68.93 0 1.68.75 1.68 1.68l-.06.45 4.41 2.53c.31-.4.79-.66 1.34-.66a1.68 1.68 0 0 1 1.68 1.68c0 .86-.64 1.57-1.47 1.68v5.11c.73.19 1.26.85 1.26 1.64a1.68 1.68 0 0 1-1.68 1.68c-.51 0-.96-.22-1.27-.58l-4.3 2.55.09.56A1.68 1.68 0 0 1 12 22M10.8 4.86 6.3 7.44l.02.24c0 .71-.44 1.32-1.06 1.57l.03 5.25 5.51-9.64m2.4 0 5.51 9.64.03-5.25c-.62-.25-1.06-.86-1.06-1.57l.02-.24-4.5-2.58Z"/></svg>
<span class="md-ellipsis">
第 9 章 &nbsp;
</span>
</a>
<label class="md-nav__link " for="__nav_10">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_10_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_10">
<span class="md-nav__icon md-icon"></span>
第 9 章 &nbsp;
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_graph/graph/" class="md-nav__link">
<span class="md-ellipsis">
9.1 &nbsp;
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_graph/graph_operations/" class="md-nav__link">
<span class="md-ellipsis">
9.2 &nbsp; 图基础操作
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_graph/graph_traversal/" class="md-nav__link">
<span class="md-ellipsis">
9.3 &nbsp; 图的遍历
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_graph/summary/" class="md-nav__link">
<span class="md-ellipsis">
9.4 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_11" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_searching/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m19.31 18.9 3.08 3.1L21 23.39l-3.12-3.07c-.69.43-1.51.68-2.38.68-2.5 0-4.5-2-4.5-4.5s2-4.5 4.5-4.5 4.5 2 4.5 4.5c0 .88-.25 1.71-.69 2.4m-3.81.1a2.5 2.5 0 0 0 0-5 2.5 2.5 0 0 0 0 5M21 4v2H3V4h18M3 16v-2h6v2H3m0-5V9h18v2h-2.03c-1.01-.63-2.2-1-3.47-1s-2.46.37-3.47 1H3Z"/></svg>
<span class="md-ellipsis">
第 10 章 &nbsp; 搜索
</span>
</a>
<label class="md-nav__link " for="__nav_11">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_11_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_11">
<span class="md-nav__icon md-icon"></span>
第 10 章 &nbsp; 搜索
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_searching/binary_search/" class="md-nav__link">
<span class="md-ellipsis">
10.1 &nbsp; 二分查找
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_searching/binary_search_insertion/" class="md-nav__link">
<span class="md-ellipsis">
10.2 &nbsp; 二分查找插入点
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_searching/binary_search_edge/" class="md-nav__link">
<span class="md-ellipsis">
10.3 &nbsp; 二分查找边界
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_searching/replace_linear_by_hashing/" class="md-nav__link">
<span class="md-ellipsis">
10.4 &nbsp; 哈希优化策略
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_searching/searching_algorithm_revisited/" class="md-nav__link">
<span class="md-ellipsis">
10.5 &nbsp; 重识搜索算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_searching/summary/" class="md-nav__link">
<span class="md-ellipsis">
10.6 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_12" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_sorting/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 17h3l-4 4-4-4h3V3h2M2 17h10v2H2M6 5v2H2V5m0 6h7v2H2v-2Z"/></svg>
<span class="md-ellipsis">
第 11 章 &nbsp; 排序
</span>
</a>
<label class="md-nav__link " for="__nav_12">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_12_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_12">
<span class="md-nav__icon md-icon"></span>
第 11 章 &nbsp; 排序
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_sorting/sorting_algorithm/" class="md-nav__link">
<span class="md-ellipsis">
11.1 &nbsp; 排序算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/selection_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.2 &nbsp; 选择排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/bubble_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.3 &nbsp; 冒泡排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/insertion_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.4 &nbsp; 插入排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/quick_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.5 &nbsp; 快速排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/merge_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.6 &nbsp; 归并排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/heap_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.7 &nbsp; 堆排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/bucket_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.8 &nbsp; 桶排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/counting_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.9 &nbsp; 计数排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/radix_sort/" class="md-nav__link">
<span class="md-ellipsis">
11.10 &nbsp; 基数排序
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_sorting/summary/" class="md-nav__link">
<span class="md-ellipsis">
11.11 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_13" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_divide_and_conquer/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M17 7v2h5V7h-5M2 9v6h5V9H2m10 0v2H9v2h3v2l3-3-3-3m5 2v2h5v-2h-5m0 4v2h5v-2h-5Z"/></svg>
<span class="md-ellipsis">
第 12 章 &nbsp; 分治
</span>
</a>
<label class="md-nav__link " for="__nav_13">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_13_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_13">
<span class="md-nav__icon md-icon"></span>
第 12 章 &nbsp; 分治
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_divide_and_conquer/divide_and_conquer/" class="md-nav__link">
<span class="md-ellipsis">
12.1 &nbsp; 分治算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_divide_and_conquer/binary_search_recur/" class="md-nav__link">
<span class="md-ellipsis">
12.2 &nbsp; 分治搜索策略
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_divide_and_conquer/build_binary_tree_problem/" class="md-nav__link">
<span class="md-ellipsis">
12.3 &nbsp; 构建树问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_divide_and_conquer/hanota_problem/" class="md-nav__link">
<span class="md-ellipsis">
12.4 &nbsp; 汉诺塔问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_divide_and_conquer/summary/" class="md-nav__link">
<span class="md-ellipsis">
12.5 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_14" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_backtracking/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M18 15a3 3 0 0 1 3 3 3 3 0 0 1-3 3 2.99 2.99 0 0 1-2.83-2H14v-2h1.17c.41-1.17 1.52-2 2.83-2m0 2a1 1 0 0 0-1 1 1 1 0 0 0 1 1 1 1 0 0 0 1-1 1 1 0 0 0-1-1m0-9a1.43 1.43 0 0 0 1.43-1.43 1.43 1.43 0 1 0-2.86 0A1.43 1.43 0 0 0 18 8m0-5.43a4 4 0 0 1 4 4C22 9.56 18 14 18 14s-4-4.44-4-7.43a4 4 0 0 1 4-4M8.83 17H10v2H8.83A2.99 2.99 0 0 1 6 21a3 3 0 0 1-3-3c0-1.31.83-2.42 2-2.83V14h2v1.17c.85.3 1.53.98 1.83 1.83M6 17a1 1 0 0 0-1 1 1 1 0 0 0 1 1 1 1 0 0 0 1-1 1 1 0 0 0-1-1M6 3a3 3 0 0 1 3 3c0 1.31-.83 2.42-2 2.83V10H5V8.83A2.99 2.99 0 0 1 3 6a3 3 0 0 1 3-3m0 2a1 1 0 0 0-1 1 1 1 0 0 0 1 1 1 1 0 0 0 1-1 1 1 0 0 0-1-1m5 14v-2h2v2h-2m-4-6H5v-2h2v2Z"/></svg>
<span class="md-ellipsis">
第 13 章 &nbsp; 回溯
</span>
</a>
<label class="md-nav__link " for="__nav_14">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_14_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_14">
<span class="md-nav__icon md-icon"></span>
第 13 章 &nbsp; 回溯
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_backtracking/backtracking_algorithm/" class="md-nav__link">
<span class="md-ellipsis">
13.1 &nbsp; 回溯算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_backtracking/permutations_problem/" class="md-nav__link">
<span class="md-ellipsis">
13.2 &nbsp; 全排列问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_backtracking/subset_sum_problem/" class="md-nav__link">
<span class="md-ellipsis">
13.3 &nbsp; 子集和问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_backtracking/n_queens_problem/" class="md-nav__link">
<span class="md-ellipsis">
13.4 &nbsp; N 皇后问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_backtracking/summary/" class="md-nav__link">
<span class="md-ellipsis">
13.5 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_15" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_dynamic_programming/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M22 15h-2v3c0 1.11-.89 2-2 2h-3v2l-3-3 3-3v2h3v-3h-2l3-3 3 3m0-11v4c0 1.1-.9 2-2 2H10v10c0 1.1-.9 2-2 2H4c-1.1 0-2-.9-2-2V4c0-1.1.9-2 2-2h16c1.1 0 2 .9 2 2M4 8h4V4H4v4m0 2v4h4v-4H4m4 10v-4H4v4h4m6-12V4h-4v4h4m6-4h-4v4h4V4Z"/></svg>
<span class="md-ellipsis">
第 14 章 &nbsp; 动态规划
</span>
</a>
<label class="md-nav__link " for="__nav_15">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_15_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_15">
<span class="md-nav__icon md-icon"></span>
第 14 章 &nbsp; 动态规划
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/intro_to_dynamic_programming/" class="md-nav__link">
<span class="md-ellipsis">
14.1 &nbsp; 初探动态规划
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/dp_problem_features/" class="md-nav__link">
<span class="md-ellipsis">
14.2 &nbsp; DP 问题特性
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/dp_solution_pipeline/" class="md-nav__link">
<span class="md-ellipsis">
14.3 &nbsp; DP 解题思路
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/knapsack_problem/" class="md-nav__link">
<span class="md-ellipsis">
14.4 &nbsp; 0-1 背包问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/unbounded_knapsack_problem/" class="md-nav__link">
<span class="md-ellipsis">
14.5 &nbsp; 完全背包问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/edit_distance_problem/" class="md-nav__link">
<span class="md-ellipsis">
14.6 &nbsp; 编辑距离问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_dynamic_programming/summary/" class="md-nav__link">
<span class="md-ellipsis">
14.7 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_16" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_greedy/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13 3c3.88 0 7 3.14 7 7 0 2.8-1.63 5.19-4 6.31V21H9v-3H8c-1.11 0-2-.89-2-2v-3H4.5c-.42 0-.66-.5-.42-.81L6 9.66A7.003 7.003 0 0 1 13 3m0-2C8.41 1 4.61 4.42 4.06 8.9L2.5 11h-.03l-.02.03c-.55.76-.62 1.76-.19 2.59.36.69 1 1.17 1.74 1.32V16c0 1.85 1.28 3.42 3 3.87V23h11v-5.5c2.5-1.67 4-4.44 4-7.5 0-4.97-4.04-9-9-9m4 7.83c0 1.54-1.36 2.77-3.42 4.64L13 14l-.58-.53C10.36 11.6 9 10.37 9 8.83c0-1.2.96-2.19 2.16-2.2h.04c.69 0 1.35.31 1.8.83.45-.52 1.11-.83 1.8-.83 1.2-.01 2.2.96 2.2 2.16v.04Z"/></svg>
<span class="md-ellipsis">
第 15 章 &nbsp; 贪心
</span>
</a>
<label class="md-nav__link " for="__nav_16">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_16_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_16">
<span class="md-nav__icon md-icon"></span>
第 15 章 &nbsp; 贪心
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_greedy/greedy_algorithm/" class="md-nav__link">
<span class="md-ellipsis">
15.1 &nbsp; 贪心算法
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_greedy/fractional_knapsack_problem/" class="md-nav__link">
<span class="md-ellipsis">
15.2 &nbsp; 分数背包问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_greedy/max_capacity_problem/" class="md-nav__link">
<span class="md-ellipsis">
15.3 &nbsp; 最大容量问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_greedy/max_product_cutting_problem/" class="md-nav__link">
<span class="md-ellipsis">
15.4 &nbsp; 最大切分乘积问题
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_greedy/summary/" class="md-nav__link">
<span class="md-ellipsis">
15.5 &nbsp; 小结
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_17" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_appendix/" class="md-nav__link ">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M11 18h2v-2h-2v2m1-16A10 10 0 0 0 2 12a10 10 0 0 0 10 10 10 10 0 0 0 10-10A10 10 0 0 0 12 2m0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8m0-14a4 4 0 0 0-4 4h2a2 2 0 0 1 2-2 2 2 0 0 1 2 2c0 2-3 1.75-3 5h2c0-2.25 3-2.5 3-5a4 4 0 0 0-4-4Z"/></svg>
<span class="md-ellipsis">
第 16 章 &nbsp; 附录
</span>
</a>
<label class="md-nav__link " for="__nav_17">
<span class="md-nav__icon md-icon"></span>
</label>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_17_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_17">
<span class="md-nav__icon md-icon"></span>
第 16 章 &nbsp; 附录
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../chapter_appendix/installation/" class="md-nav__link">
<span class="md-ellipsis">
16.1 &nbsp; 编程环境安装
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../chapter_appendix/contribution/" class="md-nav__link">
<span class="md-ellipsis">
16.2 &nbsp; 一起参与创作
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_18" >
<div class="md-nav__link md-nav__container">
<a href="../../chapter_reference/" class="md-nav__link ">
<span class="md-ellipsis">
参考文献
</span>
</a>
</div>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_18_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_18">
<span class="md-nav__icon md-icon"></span>
参考文献
</label>
<ul class="md-nav__list" data-md-scrollfix>
</ul>
</nav>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary" aria-label="目录">
<label class="md-nav__title" for="__toc">
<span class="md-nav__icon md-icon"></span>
目录
</label>
<ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#531" class="md-nav__link">
5.3.1 &nbsp; 双向队列常用操作
</a>
</li>
<li class="md-nav__item">
<a href="#532" class="md-nav__link">
5.3.2 &nbsp; 双向队列实现 *
</a>
<nav class="md-nav" aria-label="5.3.2   双向队列实现 *">
<ul class="md-nav__list">
<li class="md-nav__item">
<a href="#1" class="md-nav__link">
1. &nbsp; 基于双向链表的实现
</a>
</li>
<li class="md-nav__item">
<a href="#2" class="md-nav__link">
2. &nbsp; 基于数组的实现
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="#533" class="md-nav__link">
5.3.3 &nbsp; 双向队列应用
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<!--
Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to
deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.
-->
<!-- Tags -->
<!-- Actions -->
<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_stack_and_queue/deque.md" title="编辑此页" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M10 20H6V4h7v5h5v3.1l2-2V8l-6-6H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h4v-2m10.2-7c.1 0 .3.1.4.2l1.3 1.3c.2.2.2.6 0 .8l-1 1-2.1-2.1 1-1c.1-.1.2-.2.4-.2m0 3.9L14.1 23H12v-2.1l6.1-6.1 2.1 2.1Z"/></svg>
</a>
<!--
Hack: check whether the content contains a h1 headline. If it doesn't, the
page title (or respectively site name) is used as the main headline.
-->
<!-- Page content -->
<h1 id="53">5.3 &nbsp; 双向队列<a class="headerlink" href="#53" title="Permanent link">&para;</a></h1>
<p>在队列中,我们仅能在头部删除或在尾部添加元素。如图 5-7 所示,「双向队列 double-ended queue」提供了更高的灵活性允许在头部和尾部执行元素的添加或删除操作。</p>
<p><a class="glightbox" href="../deque.assets/deque_operations.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="双向队列的操作" src="../deque.assets/deque_operations.png" /></a></p>
<p align="center"> 图 5-7 &nbsp; 双向队列的操作 </p>
<h2 id="531">5.3.1 &nbsp; 双向队列常用操作<a class="headerlink" href="#531" title="Permanent link">&para;</a></h2>
<p>双向队列的常用操作如表 5-3 所示,具体的方法名称需要根据所使用的编程语言来确定。</p>
<p align="center"> 表 5-3 &nbsp; 双向队列操作效率 </p>
<div class="center-table">
<table>
<thead>
<tr>
<th>方法名</th>
<th>描述</th>
<th>时间复杂度</th>
</tr>
</thead>
<tbody>
<tr>
<td>pushFirst()</td>
<td>将元素添加至队首</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>pushLast()</td>
<td>将元素添加至队尾</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>popFirst()</td>
<td>删除队首元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>popLast()</td>
<td>删除队尾元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>peekFirst()</td>
<td>访问队首元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>peekLast()</td>
<td>访问队尾元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
</tbody>
</table>
</div>
<p>同样地,我们可以直接使用编程语言中已实现的双向队列类。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="1:12"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><input id="__tabbed_1_7" name="__tabbed_1" type="radio" /><input id="__tabbed_1_8" name="__tabbed_1" type="radio" /><input id="__tabbed_1_9" name="__tabbed_1" type="radio" /><input id="__tabbed_1_10" name="__tabbed_1" type="radio" /><input id="__tabbed_1_11" name="__tabbed_1" type="radio" /><input id="__tabbed_1_12" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Python</label><label for="__tabbed_1_2">C++</label><label for="__tabbed_1_3">Java</label><label for="__tabbed_1_4">C#</label><label for="__tabbed_1_5">Go</label><label for="__tabbed_1_6">Swift</label><label for="__tabbed_1_7">JS</label><label for="__tabbed_1_8">TS</label><label for="__tabbed_1_9">Dart</label><label for="__tabbed_1_10">Rust</label><label for="__tabbed_1_11">C</label><label for="__tabbed_1_12">Zig</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.py</span><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="c1"># 初始化双向队列</span>
<a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a><span class="n">deque</span><span class="p">:</span> <span class="n">deque</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="n">collections</span><span class="o">.</span><span class="n">deque</span><span class="p">()</span>
<a id="__codelineno-0-3" name="__codelineno-0-3" href="#__codelineno-0-3"></a>
<a id="__codelineno-0-4" name="__codelineno-0-4" href="#__codelineno-0-4"></a><span class="c1"># 元素入队</span>
<a id="__codelineno-0-5" name="__codelineno-0-5" href="#__codelineno-0-5"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="c1"># 添加至队尾</span>
<a id="__codelineno-0-6" name="__codelineno-0-6" href="#__codelineno-0-6"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-0-7" name="__codelineno-0-7" href="#__codelineno-0-7"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-0-8" name="__codelineno-0-8" href="#__codelineno-0-8"></a><span class="n">deque</span><span class="o">.</span><span class="n">appendleft</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span> <span class="c1"># 添加至队首</span>
<a id="__codelineno-0-9" name="__codelineno-0-9" href="#__codelineno-0-9"></a><span class="n">deque</span><span class="o">.</span><span class="n">appendleft</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-0-10" name="__codelineno-0-10" href="#__codelineno-0-10"></a>
<a id="__codelineno-0-11" name="__codelineno-0-11" href="#__codelineno-0-11"></a><span class="c1"># 访问元素</span>
<a id="__codelineno-0-12" name="__codelineno-0-12" href="#__codelineno-0-12"></a><span class="n">front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="c1"># 队首元素</span>
<a id="__codelineno-0-13" name="__codelineno-0-13" href="#__codelineno-0-13"></a><span class="n">rear</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="c1"># 队尾元素</span>
<a id="__codelineno-0-14" name="__codelineno-0-14" href="#__codelineno-0-14"></a>
<a id="__codelineno-0-15" name="__codelineno-0-15" href="#__codelineno-0-15"></a><span class="c1"># 元素出队</span>
<a id="__codelineno-0-16" name="__codelineno-0-16" href="#__codelineno-0-16"></a><span class="n">pop_front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="o">.</span><span class="n">popleft</span><span class="p">()</span> <span class="c1"># 队首元素出队</span>
<a id="__codelineno-0-17" name="__codelineno-0-17" href="#__codelineno-0-17"></a><span class="n">pop_rear</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="o">.</span><span class="n">pop</span><span class="p">()</span> <span class="c1"># 队尾元素出队</span>
<a id="__codelineno-0-18" name="__codelineno-0-18" href="#__codelineno-0-18"></a>
<a id="__codelineno-0-19" name="__codelineno-0-19" href="#__codelineno-0-19"></a><span class="c1"># 获取双向队列的长度</span>
<a id="__codelineno-0-20" name="__codelineno-0-20" href="#__codelineno-0-20"></a><span class="n">size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span>
<a id="__codelineno-0-21" name="__codelineno-0-21" href="#__codelineno-0-21"></a>
<a id="__codelineno-0-22" name="__codelineno-0-22" href="#__codelineno-0-22"></a><span class="c1"># 判断双向队列是否为空</span>
<a id="__codelineno-0-23" name="__codelineno-0-23" href="#__codelineno-0-23"></a><span class="n">is_empty</span><span class="p">:</span> <span class="nb">bool</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.cpp</span><pre><span></span><code><a id="__codelineno-1-1" name="__codelineno-1-1" href="#__codelineno-1-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-1-2" name="__codelineno-1-2" href="#__codelineno-1-2"></a><span class="n">deque</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-1-3" name="__codelineno-1-3" href="#__codelineno-1-3"></a>
<a id="__codelineno-1-4" name="__codelineno-1-4" href="#__codelineno-1-4"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-1-5" name="__codelineno-1-5" href="#__codelineno-1-5"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-1-6" name="__codelineno-1-6" href="#__codelineno-1-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-1-7" name="__codelineno-1-7" href="#__codelineno-1-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<a id="__codelineno-1-8" name="__codelineno-1-8" href="#__codelineno-1-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-1-9" name="__codelineno-1-9" href="#__codelineno-1-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-1-10" name="__codelineno-1-10" href="#__codelineno-1-10"></a>
<a id="__codelineno-1-11" name="__codelineno-1-11" href="#__codelineno-1-11"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-1-12" name="__codelineno-1-12" href="#__codelineno-1-12"></a><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">front</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-1-13" name="__codelineno-1-13" href="#__codelineno-1-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">back</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">back</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-1-14" name="__codelineno-1-14" href="#__codelineno-1-14"></a>
<a id="__codelineno-1-15" name="__codelineno-1-15" href="#__codelineno-1-15"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-1-16" name="__codelineno-1-16" href="#__codelineno-1-16"></a><span class="n">deque</span><span class="p">.</span><span class="n">pop_front</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-1-17" name="__codelineno-1-17" href="#__codelineno-1-17"></a><span class="n">deque</span><span class="p">.</span><span class="n">pop_back</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-1-18" name="__codelineno-1-18" href="#__codelineno-1-18"></a>
<a id="__codelineno-1-19" name="__codelineno-1-19" href="#__codelineno-1-19"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-1-20" name="__codelineno-1-20" href="#__codelineno-1-20"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">size</span><span class="p">();</span>
<a id="__codelineno-1-21" name="__codelineno-1-21" href="#__codelineno-1-21"></a>
<a id="__codelineno-1-22" name="__codelineno-1-22" href="#__codelineno-1-22"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-1-23" name="__codelineno-1-23" href="#__codelineno-1-23"></a><span class="kt">bool</span><span class="w"> </span><span class="n">empty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">empty</span><span class="p">();</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.java</span><pre><span></span><code><a id="__codelineno-2-1" name="__codelineno-2-1" href="#__codelineno-2-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-2-2" name="__codelineno-2-2" href="#__codelineno-2-2"></a><span class="n">Deque</span><span class="o">&lt;</span><span class="n">Integer</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">LinkedList</span><span class="o">&lt;&gt;</span><span class="p">();</span>
<a id="__codelineno-2-3" name="__codelineno-2-3" href="#__codelineno-2-3"></a>
<a id="__codelineno-2-4" name="__codelineno-2-4" href="#__codelineno-2-4"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-2-5" name="__codelineno-2-5" href="#__codelineno-2-5"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-2-6" name="__codelineno-2-6" href="#__codelineno-2-6"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-2-7" name="__codelineno-2-7" href="#__codelineno-2-7"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<a id="__codelineno-2-8" name="__codelineno-2-8" href="#__codelineno-2-8"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerFirst</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-2-9" name="__codelineno-2-9" href="#__codelineno-2-9"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerFirst</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-2-10" name="__codelineno-2-10" href="#__codelineno-2-10"></a>
<a id="__codelineno-2-11" name="__codelineno-2-11" href="#__codelineno-2-11"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-2-12" name="__codelineno-2-12" href="#__codelineno-2-12"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">peekFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-2-13" name="__codelineno-2-13" href="#__codelineno-2-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">peekLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-2-14" name="__codelineno-2-14" href="#__codelineno-2-14"></a>
<a id="__codelineno-2-15" name="__codelineno-2-15" href="#__codelineno-2-15"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-2-16" name="__codelineno-2-16" href="#__codelineno-2-16"></a><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">pollFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-2-17" name="__codelineno-2-17" href="#__codelineno-2-17"></a><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">pollLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-2-18" name="__codelineno-2-18" href="#__codelineno-2-18"></a>
<a id="__codelineno-2-19" name="__codelineno-2-19" href="#__codelineno-2-19"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-2-20" name="__codelineno-2-20" href="#__codelineno-2-20"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">size</span><span class="p">();</span>
<a id="__codelineno-2-21" name="__codelineno-2-21" href="#__codelineno-2-21"></a>
<a id="__codelineno-2-22" name="__codelineno-2-22" href="#__codelineno-2-22"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-2-23" name="__codelineno-2-23" href="#__codelineno-2-23"></a><span class="kt">boolean</span><span class="w"> </span><span class="n">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">isEmpty</span><span class="p">();</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.cs</span><pre><span></span><code><a id="__codelineno-3-1" name="__codelineno-3-1" href="#__codelineno-3-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-3-2" name="__codelineno-3-2" href="#__codelineno-3-2"></a><span class="c1">// 在 C# 中,将链表 LinkedList 看作双向队列来使用</span>
<a id="__codelineno-3-3" name="__codelineno-3-3" href="#__codelineno-3-3"></a><span class="n">LinkedList</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="p">();</span>
<a id="__codelineno-3-4" name="__codelineno-3-4" href="#__codelineno-3-4"></a>
<a id="__codelineno-3-5" name="__codelineno-3-5" href="#__codelineno-3-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-3-6" name="__codelineno-3-6" href="#__codelineno-3-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-3-7" name="__codelineno-3-7" href="#__codelineno-3-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">5</span><span class="p">);</span>
<a id="__codelineno-3-8" name="__codelineno-3-8" href="#__codelineno-3-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">4</span><span class="p">);</span>
<a id="__codelineno-3-9" name="__codelineno-3-9" href="#__codelineno-3-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddFirst</span><span class="p">(</span><span class="m">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-3-10" name="__codelineno-3-10" href="#__codelineno-3-10"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddFirst</span><span class="p">(</span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-3-11" name="__codelineno-3-11" href="#__codelineno-3-11"></a>
<a id="__codelineno-3-12" name="__codelineno-3-12" href="#__codelineno-3-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-3-13" name="__codelineno-3-13" href="#__codelineno-3-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">First</span><span class="p">.</span><span class="n">Value</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-3-14" name="__codelineno-3-14" href="#__codelineno-3-14"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Last</span><span class="p">.</span><span class="n">Value</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-3-15" name="__codelineno-3-15" href="#__codelineno-3-15"></a>
<a id="__codelineno-3-16" name="__codelineno-3-16" href="#__codelineno-3-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-3-17" name="__codelineno-3-17" href="#__codelineno-3-17"></a><span class="n">deque</span><span class="p">.</span><span class="n">RemoveFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-3-18" name="__codelineno-3-18" href="#__codelineno-3-18"></a><span class="n">deque</span><span class="p">.</span><span class="n">RemoveLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-3-19" name="__codelineno-3-19" href="#__codelineno-3-19"></a>
<a id="__codelineno-3-20" name="__codelineno-3-20" href="#__codelineno-3-20"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-3-21" name="__codelineno-3-21" href="#__codelineno-3-21"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Count</span><span class="p">;</span>
<a id="__codelineno-3-22" name="__codelineno-3-22" href="#__codelineno-3-22"></a>
<a id="__codelineno-3-23" name="__codelineno-3-23" href="#__codelineno-3-23"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-3-24" name="__codelineno-3-24" href="#__codelineno-3-24"></a><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Count</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque_test.go</span><pre><span></span><code><a id="__codelineno-4-1" name="__codelineno-4-1" href="#__codelineno-4-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-4-2" name="__codelineno-4-2" href="#__codelineno-4-2"></a><span class="c1">// 在 Go 中,将 list 作为双向队列使用</span>
<a id="__codelineno-4-3" name="__codelineno-4-3" href="#__codelineno-4-3"></a><span class="nx">deque</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">list</span><span class="p">.</span><span class="nx">New</span><span class="p">()</span>
<a id="__codelineno-4-4" name="__codelineno-4-4" href="#__codelineno-4-4"></a>
<a id="__codelineno-4-5" name="__codelineno-4-5" href="#__codelineno-4-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-4-6" name="__codelineno-4-6" href="#__codelineno-4-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-4-7" name="__codelineno-4-7" href="#__codelineno-4-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-4-8" name="__codelineno-4-8" href="#__codelineno-4-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-4-9" name="__codelineno-4-9" href="#__codelineno-4-9"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushFront</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-4-10" name="__codelineno-4-10" href="#__codelineno-4-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushFront</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-4-11" name="__codelineno-4-11" href="#__codelineno-4-11"></a>
<a id="__codelineno-4-12" name="__codelineno-4-12" href="#__codelineno-4-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-4-13" name="__codelineno-4-13" href="#__codelineno-4-13"></a><span class="nx">front</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-4-14" name="__codelineno-4-14" href="#__codelineno-4-14"></a><span class="nx">rear</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Back</span><span class="p">()</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-4-15" name="__codelineno-4-15" href="#__codelineno-4-15"></a>
<a id="__codelineno-4-16" name="__codelineno-4-16" href="#__codelineno-4-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-4-17" name="__codelineno-4-17" href="#__codelineno-4-17"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">front</span><span class="p">)</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-4-18" name="__codelineno-4-18" href="#__codelineno-4-18"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">rear</span><span class="p">)</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-4-19" name="__codelineno-4-19" href="#__codelineno-4-19"></a>
<a id="__codelineno-4-20" name="__codelineno-4-20" href="#__codelineno-4-20"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-4-21" name="__codelineno-4-21" href="#__codelineno-4-21"></a><span class="nx">size</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span>
<a id="__codelineno-4-22" name="__codelineno-4-22" href="#__codelineno-4-22"></a>
<a id="__codelineno-4-23" name="__codelineno-4-23" href="#__codelineno-4-23"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-4-24" name="__codelineno-4-24" href="#__codelineno-4-24"></a><span class="nx">isEmpty</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.swift</span><pre><span></span><code><a id="__codelineno-5-1" name="__codelineno-5-1" href="#__codelineno-5-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-5-2" name="__codelineno-5-2" href="#__codelineno-5-2"></a><span class="c1">// Swift 没有内置的双向队列类,可以把 Array 当作双向队列来使用</span>
<a id="__codelineno-5-3" name="__codelineno-5-3" href="#__codelineno-5-3"></a><span class="kd">var</span> <span class="nv">deque</span><span class="p">:</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="p">=</span> <span class="p">[]</span>
<a id="__codelineno-5-4" name="__codelineno-5-4" href="#__codelineno-5-4"></a>
<a id="__codelineno-5-5" name="__codelineno-5-5" href="#__codelineno-5-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-5-6" name="__codelineno-5-6" href="#__codelineno-5-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="c1">// 添加至队尾</span>
<a id="__codelineno-5-7" name="__codelineno-5-7" href="#__codelineno-5-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-5-8" name="__codelineno-5-8" href="#__codelineno-5-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-5-9" name="__codelineno-5-9" href="#__codelineno-5-9"></a><span class="n">deque</span><span class="p">.</span><span class="bp">insert</span><span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="n">at</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span> <span class="c1">// 添加至队首</span>
<a id="__codelineno-5-10" name="__codelineno-5-10" href="#__codelineno-5-10"></a><span class="n">deque</span><span class="p">.</span><span class="bp">insert</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="n">at</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-5-11" name="__codelineno-5-11" href="#__codelineno-5-11"></a>
<a id="__codelineno-5-12" name="__codelineno-5-12" href="#__codelineno-5-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-5-13" name="__codelineno-5-13" href="#__codelineno-5-13"></a><span class="kd">let</span> <span class="nv">peekFirst</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">first</span><span class="p">!</span> <span class="c1">// 队首元素</span>
<a id="__codelineno-5-14" name="__codelineno-5-14" href="#__codelineno-5-14"></a><span class="kd">let</span> <span class="nv">peekLast</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">last</span><span class="p">!</span> <span class="c1">// 队尾元素</span>
<a id="__codelineno-5-15" name="__codelineno-5-15" href="#__codelineno-5-15"></a>
<a id="__codelineno-5-16" name="__codelineno-5-16" href="#__codelineno-5-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-5-17" name="__codelineno-5-17" href="#__codelineno-5-17"></a><span class="c1">// 使用 Array 模拟时 popFirst 的复杂度为 O(n)</span>
<a id="__codelineno-5-18" name="__codelineno-5-18" href="#__codelineno-5-18"></a><span class="kd">let</span> <span class="nv">popFirst</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="n">removeFirst</span><span class="p">()</span> <span class="c1">// 队首元素出队</span>
<a id="__codelineno-5-19" name="__codelineno-5-19" href="#__codelineno-5-19"></a><span class="kd">let</span> <span class="nv">popLast</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">removeLast</span><span class="p">()</span> <span class="c1">// 队尾元素出队</span>
<a id="__codelineno-5-20" name="__codelineno-5-20" href="#__codelineno-5-20"></a>
<a id="__codelineno-5-21" name="__codelineno-5-21" href="#__codelineno-5-21"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-5-22" name="__codelineno-5-22" href="#__codelineno-5-22"></a><span class="kd">let</span> <span class="nv">size</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-5-23" name="__codelineno-5-23" href="#__codelineno-5-23"></a>
<a id="__codelineno-5-24" name="__codelineno-5-24" href="#__codelineno-5-24"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-5-25" name="__codelineno-5-25" href="#__codelineno-5-25"></a><span class="kd">let</span> <span class="nv">isEmpty</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">isEmpty</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.js</span><pre><span></span><code><a id="__codelineno-6-1" name="__codelineno-6-1" href="#__codelineno-6-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-6-2" name="__codelineno-6-2" href="#__codelineno-6-2"></a><span class="c1">// JavaScript 没有内置的双端队列,只能把 Array 当作双端队列来使用</span>
<a id="__codelineno-6-3" name="__codelineno-6-3" href="#__codelineno-6-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-6-4" name="__codelineno-6-4" href="#__codelineno-6-4"></a>
<a id="__codelineno-6-5" name="__codelineno-6-5" href="#__codelineno-6-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-6-6" name="__codelineno-6-6" href="#__codelineno-6-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">2</span><span class="p">);</span>
<a id="__codelineno-6-7" name="__codelineno-6-7" href="#__codelineno-6-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">5</span><span class="p">);</span>
<a id="__codelineno-6-8" name="__codelineno-6-8" href="#__codelineno-6-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">4</span><span class="p">);</span>
<a id="__codelineno-6-9" name="__codelineno-6-9" href="#__codelineno-6-9"></a><span class="c1">// 请注意由于是数组unshift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-6-10" name="__codelineno-6-10" href="#__codelineno-6-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-6-11" name="__codelineno-6-11" href="#__codelineno-6-11"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-6-12" name="__codelineno-6-12" href="#__codelineno-6-12"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列 deque = &quot;</span><span class="p">,</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-6-13" name="__codelineno-6-13" href="#__codelineno-6-13"></a>
<a id="__codelineno-6-14" name="__codelineno-6-14" href="#__codelineno-6-14"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-6-15" name="__codelineno-6-15" href="#__codelineno-6-15"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<a id="__codelineno-6-16" name="__codelineno-6-16" href="#__codelineno-6-16"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首元素 peekFirst = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">);</span>
<a id="__codelineno-6-17" name="__codelineno-6-17" href="#__codelineno-6-17"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">];</span>
<a id="__codelineno-6-18" name="__codelineno-6-18" href="#__codelineno-6-18"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾元素 peekLast = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">);</span>
<a id="__codelineno-6-19" name="__codelineno-6-19" href="#__codelineno-6-19"></a>
<a id="__codelineno-6-20" name="__codelineno-6-20" href="#__codelineno-6-20"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-6-21" name="__codelineno-6-21" href="#__codelineno-6-21"></a><span class="c1">// 请注意由于是数组shift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-6-22" name="__codelineno-6-22" href="#__codelineno-6-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">shift</span><span class="p">();</span>
<a id="__codelineno-6-23" name="__codelineno-6-23" href="#__codelineno-6-23"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首出队元素 popFront = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;,队首出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-6-24" name="__codelineno-6-24" href="#__codelineno-6-24"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<a id="__codelineno-6-25" name="__codelineno-6-25" href="#__codelineno-6-25"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾出队元素 popBack = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;,队尾出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-6-26" name="__codelineno-6-26" href="#__codelineno-6-26"></a>
<a id="__codelineno-6-27" name="__codelineno-6-27" href="#__codelineno-6-27"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-6-28" name="__codelineno-6-28" href="#__codelineno-6-28"></a><span class="kd">const</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-6-29" name="__codelineno-6-29" href="#__codelineno-6-29"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列长度 size = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">size</span><span class="p">);</span>
<a id="__codelineno-6-30" name="__codelineno-6-30" href="#__codelineno-6-30"></a>
<a id="__codelineno-6-31" name="__codelineno-6-31" href="#__codelineno-6-31"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-6-32" name="__codelineno-6-32" href="#__codelineno-6-32"></a><span class="kd">const</span><span class="w"> </span><span class="nx">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-6-33" name="__codelineno-6-33" href="#__codelineno-6-33"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列是否为空 = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">);</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.ts</span><pre><span></span><code><a id="__codelineno-7-1" name="__codelineno-7-1" href="#__codelineno-7-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-7-2" name="__codelineno-7-2" href="#__codelineno-7-2"></a><span class="c1">// TypeScript 没有内置的双端队列,只能把 Array 当作双端队列来使用</span>
<a id="__codelineno-7-3" name="__codelineno-7-3" href="#__codelineno-7-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">deque</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-7-4" name="__codelineno-7-4" href="#__codelineno-7-4"></a>
<a id="__codelineno-7-5" name="__codelineno-7-5" href="#__codelineno-7-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-7-6" name="__codelineno-7-6" href="#__codelineno-7-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">2</span><span class="p">);</span>
<a id="__codelineno-7-7" name="__codelineno-7-7" href="#__codelineno-7-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">5</span><span class="p">);</span>
<a id="__codelineno-7-8" name="__codelineno-7-8" href="#__codelineno-7-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">4</span><span class="p">);</span>
<a id="__codelineno-7-9" name="__codelineno-7-9" href="#__codelineno-7-9"></a><span class="c1">// 请注意由于是数组unshift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-7-10" name="__codelineno-7-10" href="#__codelineno-7-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-7-11" name="__codelineno-7-11" href="#__codelineno-7-11"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-7-12" name="__codelineno-7-12" href="#__codelineno-7-12"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列 deque = &quot;</span><span class="p">,</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-7-13" name="__codelineno-7-13" href="#__codelineno-7-13"></a>
<a id="__codelineno-7-14" name="__codelineno-7-14" href="#__codelineno-7-14"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-7-15" name="__codelineno-7-15" href="#__codelineno-7-15"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekFirst</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<a id="__codelineno-7-16" name="__codelineno-7-16" href="#__codelineno-7-16"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首元素 peekFirst = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">);</span>
<a id="__codelineno-7-17" name="__codelineno-7-17" href="#__codelineno-7-17"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekLast</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">];</span>
<a id="__codelineno-7-18" name="__codelineno-7-18" href="#__codelineno-7-18"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾元素 peekLast = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">);</span>
<a id="__codelineno-7-19" name="__codelineno-7-19" href="#__codelineno-7-19"></a>
<a id="__codelineno-7-20" name="__codelineno-7-20" href="#__codelineno-7-20"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-7-21" name="__codelineno-7-21" href="#__codelineno-7-21"></a><span class="c1">// 请注意由于是数组shift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-7-22" name="__codelineno-7-22" href="#__codelineno-7-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popFront</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">shift</span><span class="p">()</span><span class="w"> </span><span class="kr">as</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span>
<a id="__codelineno-7-23" name="__codelineno-7-23" href="#__codelineno-7-23"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首出队元素 popFront = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;,队首出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-7-24" name="__codelineno-7-24" href="#__codelineno-7-24"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popBack</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span><span class="w"> </span><span class="kr">as</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span>
<a id="__codelineno-7-25" name="__codelineno-7-25" href="#__codelineno-7-25"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾出队元素 popBack = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;,队尾出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-7-26" name="__codelineno-7-26" href="#__codelineno-7-26"></a>
<a id="__codelineno-7-27" name="__codelineno-7-27" href="#__codelineno-7-27"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-7-28" name="__codelineno-7-28" href="#__codelineno-7-28"></a><span class="kd">const</span><span class="w"> </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-7-29" name="__codelineno-7-29" href="#__codelineno-7-29"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列长度 size = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">size</span><span class="p">);</span>
<a id="__codelineno-7-30" name="__codelineno-7-30" href="#__codelineno-7-30"></a>
<a id="__codelineno-7-31" name="__codelineno-7-31" href="#__codelineno-7-31"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-7-32" name="__codelineno-7-32" href="#__codelineno-7-32"></a><span class="kd">const</span><span class="w"> </span><span class="nx">isEmpty</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-7-33" name="__codelineno-7-33" href="#__codelineno-7-33"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列是否为空 = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">);</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.dart</span><pre><span></span><code><a id="__codelineno-8-1" name="__codelineno-8-1" href="#__codelineno-8-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-8-2" name="__codelineno-8-2" href="#__codelineno-8-2"></a><span class="c1">// 在 Dart 中Queue 被定义为双向队列</span>
<a id="__codelineno-8-3" name="__codelineno-8-3" href="#__codelineno-8-3"></a><span class="n">Queue</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Queue</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="p">();</span>
<a id="__codelineno-8-4" name="__codelineno-8-4" href="#__codelineno-8-4"></a>
<a id="__codelineno-8-5" name="__codelineno-8-5" href="#__codelineno-8-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-8-6" name="__codelineno-8-6" href="#__codelineno-8-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">addLast</span><span class="p">(</span><span class="m">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-8-7" name="__codelineno-8-7" href="#__codelineno-8-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">addLast</span><span class="p">(</span><span class="m">5</span><span class="p">);</span>
<a id="__codelineno-8-8" name="__codelineno-8-8" href="#__codelineno-8-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">addLast</span><span class="p">(</span><span class="m">4</span><span class="p">);</span>
<a id="__codelineno-8-9" name="__codelineno-8-9" href="#__codelineno-8-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">addFirst</span><span class="p">(</span><span class="m">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-8-10" name="__codelineno-8-10" href="#__codelineno-8-10"></a><span class="n">deque</span><span class="p">.</span><span class="n">addFirst</span><span class="p">(</span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-8-11" name="__codelineno-8-11" href="#__codelineno-8-11"></a>
<a id="__codelineno-8-12" name="__codelineno-8-12" href="#__codelineno-8-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-8-13" name="__codelineno-8-13" href="#__codelineno-8-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">first</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-8-14" name="__codelineno-8-14" href="#__codelineno-8-14"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">last</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-8-15" name="__codelineno-8-15" href="#__codelineno-8-15"></a>
<a id="__codelineno-8-16" name="__codelineno-8-16" href="#__codelineno-8-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-8-17" name="__codelineno-8-17" href="#__codelineno-8-17"></a><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">removeFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-8-18" name="__codelineno-8-18" href="#__codelineno-8-18"></a><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">removeLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-8-19" name="__codelineno-8-19" href="#__codelineno-8-19"></a>
<a id="__codelineno-8-20" name="__codelineno-8-20" href="#__codelineno-8-20"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-8-21" name="__codelineno-8-21" href="#__codelineno-8-21"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">length</span><span class="p">;</span>
<a id="__codelineno-8-22" name="__codelineno-8-22" href="#__codelineno-8-22"></a>
<a id="__codelineno-8-23" name="__codelineno-8-23" href="#__codelineno-8-23"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-8-24" name="__codelineno-8-24" href="#__codelineno-8-24"></a><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">;</span><span class="n">W</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.rs</span><pre><span></span><code><a id="__codelineno-9-1" name="__codelineno-9-1" href="#__codelineno-9-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-9-2" name="__codelineno-9-2" href="#__codelineno-9-2"></a><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">deque</span>: <span class="nc">VecDeque</span><span class="o">&lt;</span><span class="kt">u32</span><span class="o">&gt;</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">VecDeque</span>::<span class="n">new</span><span class="p">();</span>
<a id="__codelineno-9-3" name="__codelineno-9-3" href="#__codelineno-9-3"></a>
<a id="__codelineno-9-4" name="__codelineno-9-4" href="#__codelineno-9-4"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-9-5" name="__codelineno-9-5" href="#__codelineno-9-5"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-9-6" name="__codelineno-9-6" href="#__codelineno-9-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-9-7" name="__codelineno-9-7" href="#__codelineno-9-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<a id="__codelineno-9-8" name="__codelineno-9-8" href="#__codelineno-9-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-9-9" name="__codelineno-9-9" href="#__codelineno-9-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-9-10" name="__codelineno-9-10" href="#__codelineno-9-10"></a>
<a id="__codelineno-9-11" name="__codelineno-9-11" href="#__codelineno-9-11"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-9-12" name="__codelineno-9-12" href="#__codelineno-9-12"></a><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">front</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">front</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-9-13" name="__codelineno-9-13" href="#__codelineno-9-13"></a><span class="p">}</span>
<a id="__codelineno-9-14" name="__codelineno-9-14" href="#__codelineno-9-14"></a><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">rear</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">back</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-9-15" name="__codelineno-9-15" href="#__codelineno-9-15"></a><span class="p">}</span>
<a id="__codelineno-9-16" name="__codelineno-9-16" href="#__codelineno-9-16"></a>
<a id="__codelineno-9-17" name="__codelineno-9-17" href="#__codelineno-9-17"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-9-18" name="__codelineno-9-18" href="#__codelineno-9-18"></a><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">pop_front</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">pop_front</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-9-19" name="__codelineno-9-19" href="#__codelineno-9-19"></a><span class="p">}</span>
<a id="__codelineno-9-20" name="__codelineno-9-20" href="#__codelineno-9-20"></a><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">pop_rear</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">pop_back</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-9-21" name="__codelineno-9-21" href="#__codelineno-9-21"></a><span class="p">}</span>
<a id="__codelineno-9-22" name="__codelineno-9-22" href="#__codelineno-9-22"></a>
<a id="__codelineno-9-23" name="__codelineno-9-23" href="#__codelineno-9-23"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-9-24" name="__codelineno-9-24" href="#__codelineno-9-24"></a><span class="kd">let</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">len</span><span class="p">();</span>
<a id="__codelineno-9-25" name="__codelineno-9-25" href="#__codelineno-9-25"></a>
<a id="__codelineno-9-26" name="__codelineno-9-26" href="#__codelineno-9-26"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-9-27" name="__codelineno-9-27" href="#__codelineno-9-27"></a><span class="kd">let</span><span class="w"> </span><span class="n">is_empty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">is_empty</span><span class="p">();</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.c</span><pre><span></span><code><a id="__codelineno-10-1" name="__codelineno-10-1" href="#__codelineno-10-1"></a><span class="c1">// C 未提供内置双向队列</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.zig</span><pre><span></span><code><a id="__codelineno-11-1" name="__codelineno-11-1" href="#__codelineno-11-1"></a>
</code></pre></div>
</div>
</div>
</div>
<h2 id="532">5.3.2 &nbsp; 双向队列实现 *<a class="headerlink" href="#532" title="Permanent link">&para;</a></h2>
<p>双向队列的实现与队列类似,可以选择链表或数组作为底层数据结构。</p>
<h3 id="1">1. &nbsp; 基于双向链表的实现<a class="headerlink" href="#1" title="Permanent link">&para;</a></h3>
<p>回顾上一节内容,我们使用普通单向链表来实现队列,因为它可以方便地删除头节点(对应出队操作)和在尾节点后添加新节点(对应入队操作)。</p>
<p>对于双向队列而言,头部和尾部都可以执行入队和出队操作。换句话说,双向队列需要实现另一个对称方向的操作。为此,我们采用“双向链表”作为双向队列的底层数据结构。</p>
<p>如图 5-8 所示,我们将双向链表的头节点和尾节点视为双向队列的队首和队尾,同时实现在两端添加和删除节点的功能。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="2:5"><input checked="checked" id="__tabbed_2_1" name="__tabbed_2" type="radio" /><input id="__tabbed_2_2" name="__tabbed_2" type="radio" /><input id="__tabbed_2_3" name="__tabbed_2" type="radio" /><input id="__tabbed_2_4" name="__tabbed_2" type="radio" /><input id="__tabbed_2_5" name="__tabbed_2" type="radio" /><div class="tabbed-labels"><label for="__tabbed_2_1">LinkedListDeque</label><label for="__tabbed_2_2">pushLast()</label><label for="__tabbed_2_3">pushFirst()</label><label for="__tabbed_2_4">popLast()</label><label for="__tabbed_2_5">popFirst()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/linkedlist_deque.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="基于链表实现双向队列的入队出队操作" src="../deque.assets/linkedlist_deque.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/linkedlist_deque_push_last.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="linkedlist_deque_push_last" src="../deque.assets/linkedlist_deque_push_last.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/linkedlist_deque_push_first.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="linkedlist_deque_push_first" src="../deque.assets/linkedlist_deque_push_first.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/linkedlist_deque_pop_last.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="linkedlist_deque_pop_last" src="../deque.assets/linkedlist_deque_pop_last.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/linkedlist_deque_pop_first.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="linkedlist_deque_pop_first" src="../deque.assets/linkedlist_deque_pop_first.png" /></a></p>
</div>
</div>
</div>
<p align="center"> 图 5-8 &nbsp; 基于链表实现双向队列的入队出队操作 </p>
<p>实现代码如下所示。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="3:12"><input checked="checked" id="__tabbed_3_1" name="__tabbed_3" type="radio" /><input id="__tabbed_3_2" name="__tabbed_3" type="radio" /><input id="__tabbed_3_3" name="__tabbed_3" type="radio" /><input id="__tabbed_3_4" name="__tabbed_3" type="radio" /><input id="__tabbed_3_5" name="__tabbed_3" type="radio" /><input id="__tabbed_3_6" name="__tabbed_3" type="radio" /><input id="__tabbed_3_7" name="__tabbed_3" type="radio" /><input id="__tabbed_3_8" name="__tabbed_3" type="radio" /><input id="__tabbed_3_9" name="__tabbed_3" type="radio" /><input id="__tabbed_3_10" name="__tabbed_3" type="radio" /><input id="__tabbed_3_11" name="__tabbed_3" type="radio" /><input id="__tabbed_3_12" name="__tabbed_3" type="radio" /><div class="tabbed-labels"><label for="__tabbed_3_1">Python</label><label for="__tabbed_3_2">C++</label><label for="__tabbed_3_3">Java</label><label for="__tabbed_3_4">C#</label><label for="__tabbed_3_5">Go</label><label for="__tabbed_3_6">Swift</label><label for="__tabbed_3_7">JS</label><label for="__tabbed_3_8">TS</label><label for="__tabbed_3_9">Dart</label><label for="__tabbed_3_10">Rust</label><label for="__tabbed_3_11">C</label><label for="__tabbed_3_12">Zig</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.py</span><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="k">class</span> <span class="nc">ListNode</span><span class="p">:</span>
<a id="__codelineno-12-2" name="__codelineno-12-2" href="#__codelineno-12-2"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;双向链表节点&quot;&quot;&quot;</span>
<a id="__codelineno-12-3" name="__codelineno-12-3" href="#__codelineno-12-3"></a>
<a id="__codelineno-12-4" name="__codelineno-12-4" href="#__codelineno-12-4"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-12-5" name="__codelineno-12-5" href="#__codelineno-12-5"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-12-6" name="__codelineno-12-6" href="#__codelineno-12-6"></a> <span class="bp">self</span><span class="o">.</span><span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">val</span>
<a id="__codelineno-12-7" name="__codelineno-12-7" href="#__codelineno-12-7"></a> <span class="bp">self</span><span class="o">.</span><span class="n">next</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 后继节点引用</span>
<a id="__codelineno-12-8" name="__codelineno-12-8" href="#__codelineno-12-8"></a> <span class="bp">self</span><span class="o">.</span><span class="n">prev</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 前驱节点引用</span>
<a id="__codelineno-12-9" name="__codelineno-12-9" href="#__codelineno-12-9"></a>
<a id="__codelineno-12-10" name="__codelineno-12-10" href="#__codelineno-12-10"></a><span class="k">class</span> <span class="nc">LinkedListDeque</span><span class="p">:</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;基于双向链表实现的双向队列&quot;&quot;&quot;</span>
<a id="__codelineno-12-12" name="__codelineno-12-12" href="#__codelineno-12-12"></a>
<a id="__codelineno-12-13" name="__codelineno-12-13" href="#__codelineno-12-13"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<a id="__codelineno-12-14" name="__codelineno-12-14" href="#__codelineno-12-14"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-12-15" name="__codelineno-12-15" href="#__codelineno-12-15"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 头节点 front</span>
<a id="__codelineno-12-16" name="__codelineno-12-16" href="#__codelineno-12-16"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 尾节点 rear</span>
<a id="__codelineno-12-17" name="__codelineno-12-17" href="#__codelineno-12-17"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1"># 双向队列的长度</span>
<a id="__codelineno-12-18" name="__codelineno-12-18" href="#__codelineno-12-18"></a>
<a id="__codelineno-12-19" name="__codelineno-12-19" href="#__codelineno-12-19"></a> <span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-20" name="__codelineno-12-20" href="#__codelineno-12-20"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的长度&quot;&quot;&quot;</span>
<a id="__codelineno-12-21" name="__codelineno-12-21" href="#__codelineno-12-21"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span>
<a id="__codelineno-12-22" name="__codelineno-12-22" href="#__codelineno-12-22"></a>
<a id="__codelineno-12-23" name="__codelineno-12-23" href="#__codelineno-12-23"></a> <span class="k">def</span> <span class="nf">is_empty</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">bool</span><span class="p">:</span>
<a id="__codelineno-12-24" name="__codelineno-12-24" href="#__codelineno-12-24"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;判断双向队列是否为空&quot;&quot;&quot;</span>
<a id="__codelineno-12-25" name="__codelineno-12-25" href="#__codelineno-12-25"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()</span> <span class="o">==</span> <span class="mi">0</span>
<a id="__codelineno-12-26" name="__codelineno-12-26" href="#__codelineno-12-26"></a>
<a id="__codelineno-12-27" name="__codelineno-12-27" href="#__codelineno-12-27"></a> <span class="k">def</span> <span class="nf">push</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">is_front</span><span class="p">:</span> <span class="nb">bool</span><span class="p">):</span>
<a id="__codelineno-12-28" name="__codelineno-12-28" href="#__codelineno-12-28"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;入队操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-29" name="__codelineno-12-29" href="#__codelineno-12-29"></a> <span class="n">node</span> <span class="o">=</span> <span class="n">ListNode</span><span class="p">(</span><span class="n">num</span><span class="p">)</span>
<a id="__codelineno-12-30" name="__codelineno-12-30" href="#__codelineno-12-30"></a> <span class="c1"># 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-12-31" name="__codelineno-12-31" href="#__codelineno-12-31"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-32" name="__codelineno-12-32" href="#__codelineno-12-32"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-33" name="__codelineno-12-33" href="#__codelineno-12-33"></a> <span class="c1"># 队首入队操作</span>
<a id="__codelineno-12-34" name="__codelineno-12-34" href="#__codelineno-12-34"></a> <span class="k">elif</span> <span class="n">is_front</span><span class="p">:</span>
<a id="__codelineno-12-35" name="__codelineno-12-35" href="#__codelineno-12-35"></a> <span class="c1"># 将 node 添加至链表头部</span>
<a id="__codelineno-12-36" name="__codelineno-12-36" href="#__codelineno-12-36"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-37" name="__codelineno-12-37" href="#__codelineno-12-37"></a> <span class="n">node</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span>
<a id="__codelineno-12-38" name="__codelineno-12-38" href="#__codelineno-12-38"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">=</span> <span class="n">node</span> <span class="c1"># 更新头节点</span>
<a id="__codelineno-12-39" name="__codelineno-12-39" href="#__codelineno-12-39"></a> <span class="c1"># 队尾入队操作</span>
<a id="__codelineno-12-40" name="__codelineno-12-40" href="#__codelineno-12-40"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-41" name="__codelineno-12-41" href="#__codelineno-12-41"></a> <span class="c1"># 将 node 添加至链表尾部</span>
<a id="__codelineno-12-42" name="__codelineno-12-42" href="#__codelineno-12-42"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-43" name="__codelineno-12-43" href="#__codelineno-12-43"></a> <span class="n">node</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span>
<a id="__codelineno-12-44" name="__codelineno-12-44" href="#__codelineno-12-44"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span> <span class="o">=</span> <span class="n">node</span> <span class="c1"># 更新尾节点</span>
<a id="__codelineno-12-45" name="__codelineno-12-45" href="#__codelineno-12-45"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">+=</span> <span class="mi">1</span> <span class="c1"># 更新队列长度</span>
<a id="__codelineno-12-46" name="__codelineno-12-46" href="#__codelineno-12-46"></a>
<a id="__codelineno-12-47" name="__codelineno-12-47" href="#__codelineno-12-47"></a> <span class="k">def</span> <span class="nf">push_first</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-12-48" name="__codelineno-12-48" href="#__codelineno-12-48"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首入队&quot;&quot;&quot;</span>
<a id="__codelineno-12-49" name="__codelineno-12-49" href="#__codelineno-12-49"></a> <span class="bp">self</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<a id="__codelineno-12-50" name="__codelineno-12-50" href="#__codelineno-12-50"></a>
<a id="__codelineno-12-51" name="__codelineno-12-51" href="#__codelineno-12-51"></a> <span class="k">def</span> <span class="nf">push_last</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-12-52" name="__codelineno-12-52" href="#__codelineno-12-52"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾入队&quot;&quot;&quot;</span>
<a id="__codelineno-12-53" name="__codelineno-12-53" href="#__codelineno-12-53"></a> <span class="bp">self</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<a id="__codelineno-12-54" name="__codelineno-12-54" href="#__codelineno-12-54"></a>
<a id="__codelineno-12-55" name="__codelineno-12-55" href="#__codelineno-12-55"></a> <span class="k">def</span> <span class="nf">pop</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">is_front</span><span class="p">:</span> <span class="nb">bool</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-56" name="__codelineno-12-56" href="#__codelineno-12-56"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;出队操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-57" name="__codelineno-12-57" href="#__codelineno-12-57"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-58" name="__codelineno-12-58" href="#__codelineno-12-58"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-12-59" name="__codelineno-12-59" href="#__codelineno-12-59"></a> <span class="c1"># 队首出队操作</span>
<a id="__codelineno-12-60" name="__codelineno-12-60" href="#__codelineno-12-60"></a> <span class="k">if</span> <span class="n">is_front</span><span class="p">:</span>
<a id="__codelineno-12-61" name="__codelineno-12-61" href="#__codelineno-12-61"></a> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="o">.</span><span class="n">val</span> <span class="c1"># 暂存头节点值</span>
<a id="__codelineno-12-62" name="__codelineno-12-62" href="#__codelineno-12-62"></a> <span class="c1"># 删除头节点</span>
<a id="__codelineno-12-63" name="__codelineno-12-63" href="#__codelineno-12-63"></a> <span class="n">fnext</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="o">.</span><span class="n">next</span>
<a id="__codelineno-12-64" name="__codelineno-12-64" href="#__codelineno-12-64"></a> <span class="k">if</span> <span class="n">fnext</span> <span class="o">!=</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-65" name="__codelineno-12-65" href="#__codelineno-12-65"></a> <span class="n">fnext</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-66" name="__codelineno-12-66" href="#__codelineno-12-66"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-67" name="__codelineno-12-67" href="#__codelineno-12-67"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">=</span> <span class="n">fnext</span> <span class="c1"># 更新头节点</span>
<a id="__codelineno-12-68" name="__codelineno-12-68" href="#__codelineno-12-68"></a> <span class="c1"># 队尾出队操作</span>
<a id="__codelineno-12-69" name="__codelineno-12-69" href="#__codelineno-12-69"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-70" name="__codelineno-12-70" href="#__codelineno-12-70"></a> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="o">.</span><span class="n">val</span> <span class="c1"># 暂存尾节点值</span>
<a id="__codelineno-12-71" name="__codelineno-12-71" href="#__codelineno-12-71"></a> <span class="c1"># 删除尾节点</span>
<a id="__codelineno-12-72" name="__codelineno-12-72" href="#__codelineno-12-72"></a> <span class="n">rprev</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="o">.</span><span class="n">prev</span>
<a id="__codelineno-12-73" name="__codelineno-12-73" href="#__codelineno-12-73"></a> <span class="k">if</span> <span class="n">rprev</span> <span class="o">!=</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-74" name="__codelineno-12-74" href="#__codelineno-12-74"></a> <span class="n">rprev</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-75" name="__codelineno-12-75" href="#__codelineno-12-75"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-76" name="__codelineno-12-76" href="#__codelineno-12-76"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span> <span class="o">=</span> <span class="n">rprev</span> <span class="c1"># 更新尾节点</span>
<a id="__codelineno-12-77" name="__codelineno-12-77" href="#__codelineno-12-77"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">-=</span> <span class="mi">1</span> <span class="c1"># 更新队列长度</span>
<a id="__codelineno-12-78" name="__codelineno-12-78" href="#__codelineno-12-78"></a> <span class="k">return</span> <span class="n">val</span>
<a id="__codelineno-12-79" name="__codelineno-12-79" href="#__codelineno-12-79"></a>
<a id="__codelineno-12-80" name="__codelineno-12-80" href="#__codelineno-12-80"></a> <span class="k">def</span> <span class="nf">pop_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-81" name="__codelineno-12-81" href="#__codelineno-12-81"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首出队&quot;&quot;&quot;</span>
<a id="__codelineno-12-82" name="__codelineno-12-82" href="#__codelineno-12-82"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">True</span><span class="p">)</span>
<a id="__codelineno-12-83" name="__codelineno-12-83" href="#__codelineno-12-83"></a>
<a id="__codelineno-12-84" name="__codelineno-12-84" href="#__codelineno-12-84"></a> <span class="k">def</span> <span class="nf">pop_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-85" name="__codelineno-12-85" href="#__codelineno-12-85"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾出队&quot;&quot;&quot;</span>
<a id="__codelineno-12-86" name="__codelineno-12-86" href="#__codelineno-12-86"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">False</span><span class="p">)</span>
<a id="__codelineno-12-87" name="__codelineno-12-87" href="#__codelineno-12-87"></a>
<a id="__codelineno-12-88" name="__codelineno-12-88" href="#__codelineno-12-88"></a> <span class="k">def</span> <span class="nf">peek_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-89" name="__codelineno-12-89" href="#__codelineno-12-89"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队首元素&quot;&quot;&quot;</span>
<a id="__codelineno-12-90" name="__codelineno-12-90" href="#__codelineno-12-90"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-91" name="__codelineno-12-91" href="#__codelineno-12-91"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-12-92" name="__codelineno-12-92" href="#__codelineno-12-92"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-93" name="__codelineno-12-93" href="#__codelineno-12-93"></a>
<a id="__codelineno-12-94" name="__codelineno-12-94" href="#__codelineno-12-94"></a> <span class="k">def</span> <span class="nf">peek_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-95" name="__codelineno-12-95" href="#__codelineno-12-95"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队尾元素&quot;&quot;&quot;</span>
<a id="__codelineno-12-96" name="__codelineno-12-96" href="#__codelineno-12-96"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-97" name="__codelineno-12-97" href="#__codelineno-12-97"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-12-98" name="__codelineno-12-98" href="#__codelineno-12-98"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_rear</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-99" name="__codelineno-12-99" href="#__codelineno-12-99"></a>
<a id="__codelineno-12-100" name="__codelineno-12-100" href="#__codelineno-12-100"></a> <span class="k">def</span> <span class="nf">to_array</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]:</span>
<a id="__codelineno-12-101" name="__codelineno-12-101" href="#__codelineno-12-101"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;返回数组用于打印&quot;&quot;&quot;</span>
<a id="__codelineno-12-102" name="__codelineno-12-102" href="#__codelineno-12-102"></a> <span class="n">node</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span>
<a id="__codelineno-12-103" name="__codelineno-12-103" href="#__codelineno-12-103"></a> <span class="n">res</span> <span class="o">=</span> <span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">*</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()</span>
<a id="__codelineno-12-104" name="__codelineno-12-104" href="#__codelineno-12-104"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()):</span>
<a id="__codelineno-12-105" name="__codelineno-12-105" href="#__codelineno-12-105"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="o">=</span> <span class="n">node</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-106" name="__codelineno-12-106" href="#__codelineno-12-106"></a> <span class="n">node</span> <span class="o">=</span> <span class="n">node</span><span class="o">.</span><span class="n">next</span>
<a id="__codelineno-12-107" name="__codelineno-12-107" href="#__codelineno-12-107"></a> <span class="k">return</span> <span class="n">res</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.cpp</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">DoublyListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-3" name="__codelineno-13-3" href="#__codelineno-13-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点指针</span>
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点指针</span>
<a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">val</span><span class="p">(</span><span class="n">val</span><span class="p">),</span><span class="w"> </span><span class="n">prev</span><span class="p">(</span><span class="k">nullptr</span><span class="p">),</span><span class="w"> </span><span class="n">next</span><span class="p">(</span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a><span class="p">};</span>
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a>
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="w"> </span><span class="k">private</span><span class="o">:</span>
<a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ,尾节点 rear</span>
<a id="__codelineno-13-14" name="__codelineno-13-14" href="#__codelineno-13-14"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-13-15" name="__codelineno-13-15" href="#__codelineno-13-15"></a>
<a id="__codelineno-13-16" name="__codelineno-13-16" href="#__codelineno-13-16"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-13-17" name="__codelineno-13-17" href="#__codelineno-13-17"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-13-18" name="__codelineno-13-18" href="#__codelineno-13-18"></a><span class="w"> </span><span class="n">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">front</span><span class="p">(</span><span class="k">nullptr</span><span class="p">),</span><span class="w"> </span><span class="n">rear</span><span class="p">(</span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-19" name="__codelineno-13-19" href="#__codelineno-13-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-20" name="__codelineno-13-20" href="#__codelineno-13-20"></a>
<a id="__codelineno-13-21" name="__codelineno-13-21" href="#__codelineno-13-21"></a><span class="w"> </span><span class="cm">/* 析构方法 */</span>
<a id="__codelineno-13-22" name="__codelineno-13-22" href="#__codelineno-13-22"></a><span class="w"> </span><span class="o">~</span><span class="n">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-23" name="__codelineno-13-23" href="#__codelineno-13-23"></a><span class="w"> </span><span class="c1">// 遍历链表删除节点,释放内存</span>
<a id="__codelineno-13-24" name="__codelineno-13-24" href="#__codelineno-13-24"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">pre</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">cur</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-13-25" name="__codelineno-13-25" href="#__codelineno-13-25"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">cur</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-26" name="__codelineno-13-26" href="#__codelineno-13-26"></a><span class="w"> </span><span class="n">pre</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">cur</span><span class="p">;</span>
<a id="__codelineno-13-27" name="__codelineno-13-27" href="#__codelineno-13-27"></a><span class="w"> </span><span class="n">cur</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">cur</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-13-28" name="__codelineno-13-28" href="#__codelineno-13-28"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">pre</span><span class="p">;</span>
<a id="__codelineno-13-29" name="__codelineno-13-29" href="#__codelineno-13-29"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-30" name="__codelineno-13-30" href="#__codelineno-13-30"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-31" name="__codelineno-13-31" href="#__codelineno-13-31"></a>
<a id="__codelineno-13-32" name="__codelineno-13-32" href="#__codelineno-13-32"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-13-33" name="__codelineno-13-33" href="#__codelineno-13-33"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-34" name="__codelineno-13-34" href="#__codelineno-13-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-13-35" name="__codelineno-13-35" href="#__codelineno-13-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-36" name="__codelineno-13-36" href="#__codelineno-13-36"></a>
<a id="__codelineno-13-37" name="__codelineno-13-37" href="#__codelineno-13-37"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-13-38" name="__codelineno-13-38" href="#__codelineno-13-38"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-39" name="__codelineno-13-39" href="#__codelineno-13-39"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-13-40" name="__codelineno-13-40" href="#__codelineno-13-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-41" name="__codelineno-13-41" href="#__codelineno-13-41"></a>
<a id="__codelineno-13-42" name="__codelineno-13-42" href="#__codelineno-13-42"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-13-43" name="__codelineno-13-43" href="#__codelineno-13-43"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-44" name="__codelineno-13-44" href="#__codelineno-13-44"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">DoublyListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-13-45" name="__codelineno-13-45" href="#__codelineno-13-45"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-13-46" name="__codelineno-13-46" href="#__codelineno-13-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-13-47" name="__codelineno-13-47" href="#__codelineno-13-47"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-13-48" name="__codelineno-13-48" href="#__codelineno-13-48"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-13-49" name="__codelineno-13-49" href="#__codelineno-13-49"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-50" name="__codelineno-13-50" href="#__codelineno-13-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-13-51" name="__codelineno-13-51" href="#__codelineno-13-51"></a><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-13-52" name="__codelineno-13-52" href="#__codelineno-13-52"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-13-53" name="__codelineno-13-53" href="#__codelineno-13-53"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-13-54" name="__codelineno-13-54" href="#__codelineno-13-54"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-13-55" name="__codelineno-13-55" href="#__codelineno-13-55"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-56" name="__codelineno-13-56" href="#__codelineno-13-56"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-13-57" name="__codelineno-13-57" href="#__codelineno-13-57"></a><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-13-58" name="__codelineno-13-58" href="#__codelineno-13-58"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-13-59" name="__codelineno-13-59" href="#__codelineno-13-59"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-13-60" name="__codelineno-13-60" href="#__codelineno-13-60"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-61" name="__codelineno-13-61" href="#__codelineno-13-61"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-13-62" name="__codelineno-13-62" href="#__codelineno-13-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-63" name="__codelineno-13-63" href="#__codelineno-13-63"></a>
<a id="__codelineno-13-64" name="__codelineno-13-64" href="#__codelineno-13-64"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-13-65" name="__codelineno-13-65" href="#__codelineno-13-65"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-66" name="__codelineno-13-66" href="#__codelineno-13-66"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-13-67" name="__codelineno-13-67" href="#__codelineno-13-67"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-68" name="__codelineno-13-68" href="#__codelineno-13-68"></a>
<a id="__codelineno-13-69" name="__codelineno-13-69" href="#__codelineno-13-69"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-13-70" name="__codelineno-13-70" href="#__codelineno-13-70"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-71" name="__codelineno-13-71" href="#__codelineno-13-71"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-13-72" name="__codelineno-13-72" href="#__codelineno-13-72"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-73" name="__codelineno-13-73" href="#__codelineno-13-73"></a>
<a id="__codelineno-13-74" name="__codelineno-13-74" href="#__codelineno-13-74"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-13-75" name="__codelineno-13-75" href="#__codelineno-13-75"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-76" name="__codelineno-13-76" href="#__codelineno-13-76"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-13-77" name="__codelineno-13-77" href="#__codelineno-13-77"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-13-78" name="__codelineno-13-78" href="#__codelineno-13-78"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-79" name="__codelineno-13-79" href="#__codelineno-13-79"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-13-80" name="__codelineno-13-80" href="#__codelineno-13-80"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-81" name="__codelineno-13-81" href="#__codelineno-13-81"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-13-82" name="__codelineno-13-82" href="#__codelineno-13-82"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-13-83" name="__codelineno-13-83" href="#__codelineno-13-83"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-13-84" name="__codelineno-13-84" href="#__codelineno-13-84"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-85" name="__codelineno-13-85" href="#__codelineno-13-85"></a><span class="w"> </span><span class="n">fNext</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-86" name="__codelineno-13-86" href="#__codelineno-13-86"></a><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-87" name="__codelineno-13-87" href="#__codelineno-13-87"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-13-88" name="__codelineno-13-88" href="#__codelineno-13-88"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-89" name="__codelineno-13-89" href="#__codelineno-13-89"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-13-90" name="__codelineno-13-90" href="#__codelineno-13-90"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-13-91" name="__codelineno-13-91" href="#__codelineno-13-91"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-92" name="__codelineno-13-92" href="#__codelineno-13-92"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-13-93" name="__codelineno-13-93" href="#__codelineno-13-93"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-13-94" name="__codelineno-13-94" href="#__codelineno-13-94"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-13-95" name="__codelineno-13-95" href="#__codelineno-13-95"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-96" name="__codelineno-13-96" href="#__codelineno-13-96"></a><span class="w"> </span><span class="n">rPrev</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-97" name="__codelineno-13-97" href="#__codelineno-13-97"></a><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-13-98" name="__codelineno-13-98" href="#__codelineno-13-98"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-13-99" name="__codelineno-13-99" href="#__codelineno-13-99"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-100" name="__codelineno-13-100" href="#__codelineno-13-100"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-13-101" name="__codelineno-13-101" href="#__codelineno-13-101"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-102" name="__codelineno-13-102" href="#__codelineno-13-102"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-13-103" name="__codelineno-13-103" href="#__codelineno-13-103"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-104" name="__codelineno-13-104" href="#__codelineno-13-104"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-105" name="__codelineno-13-105" href="#__codelineno-13-105"></a>
<a id="__codelineno-13-106" name="__codelineno-13-106" href="#__codelineno-13-106"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-13-107" name="__codelineno-13-107" href="#__codelineno-13-107"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-108" name="__codelineno-13-108" href="#__codelineno-13-108"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-13-109" name="__codelineno-13-109" href="#__codelineno-13-109"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-110" name="__codelineno-13-110" href="#__codelineno-13-110"></a>
<a id="__codelineno-13-111" name="__codelineno-13-111" href="#__codelineno-13-111"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-13-112" name="__codelineno-13-112" href="#__codelineno-13-112"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-113" name="__codelineno-13-113" href="#__codelineno-13-113"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-13-114" name="__codelineno-13-114" href="#__codelineno-13-114"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-115" name="__codelineno-13-115" href="#__codelineno-13-115"></a>
<a id="__codelineno-13-116" name="__codelineno-13-116" href="#__codelineno-13-116"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-13-117" name="__codelineno-13-117" href="#__codelineno-13-117"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-118" name="__codelineno-13-118" href="#__codelineno-13-118"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-13-119" name="__codelineno-13-119" href="#__codelineno-13-119"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-13-120" name="__codelineno-13-120" href="#__codelineno-13-120"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-121" name="__codelineno-13-121" href="#__codelineno-13-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-122" name="__codelineno-13-122" href="#__codelineno-13-122"></a>
<a id="__codelineno-13-123" name="__codelineno-13-123" href="#__codelineno-13-123"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-13-124" name="__codelineno-13-124" href="#__codelineno-13-124"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-125" name="__codelineno-13-125" href="#__codelineno-13-125"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-13-126" name="__codelineno-13-126" href="#__codelineno-13-126"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-13-127" name="__codelineno-13-127" href="#__codelineno-13-127"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-128" name="__codelineno-13-128" href="#__codelineno-13-128"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-129" name="__codelineno-13-129" href="#__codelineno-13-129"></a>
<a id="__codelineno-13-130" name="__codelineno-13-130" href="#__codelineno-13-130"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-13-131" name="__codelineno-13-131" href="#__codelineno-13-131"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">toVector</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-132" name="__codelineno-13-132" href="#__codelineno-13-132"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-13-133" name="__codelineno-13-133" href="#__codelineno-13-133"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">res</span><span class="p">(</span><span class="n">size</span><span class="p">());</span>
<a id="__codelineno-13-134" name="__codelineno-13-134" href="#__codelineno-13-134"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">size</span><span class="p">();</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-135" name="__codelineno-13-135" href="#__codelineno-13-135"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-13-136" name="__codelineno-13-136" href="#__codelineno-13-136"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-13-137" name="__codelineno-13-137" href="#__codelineno-13-137"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-138" name="__codelineno-13-138" href="#__codelineno-13-138"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-13-139" name="__codelineno-13-139" href="#__codelineno-13-139"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-140" name="__codelineno-13-140" href="#__codelineno-13-140"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.java</span><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="kd">class</span> <span class="nc">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-3" name="__codelineno-14-3" href="#__codelineno-14-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用</span>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a>
<a id="__codelineno-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="na">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a><span class="w"> </span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a><span class="p">}</span>
<a id="__codelineno-14-12" name="__codelineno-14-12" href="#__codelineno-14-12"></a>
<a id="__codelineno-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a><span class="kd">class</span> <span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ,尾节点 rear</span>
<a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-14-17" name="__codelineno-14-17" href="#__codelineno-14-17"></a>
<a id="__codelineno-14-18" name="__codelineno-14-18" href="#__codelineno-14-18"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-19" name="__codelineno-14-19" href="#__codelineno-14-19"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-20" name="__codelineno-14-20" href="#__codelineno-14-20"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-21" name="__codelineno-14-21" href="#__codelineno-14-21"></a>
<a id="__codelineno-14-22" name="__codelineno-14-22" href="#__codelineno-14-22"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-14-23" name="__codelineno-14-23" href="#__codelineno-14-23"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-24" name="__codelineno-14-24" href="#__codelineno-14-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-14-25" name="__codelineno-14-25" href="#__codelineno-14-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-26" name="__codelineno-14-26" href="#__codelineno-14-26"></a>
<a id="__codelineno-14-27" name="__codelineno-14-27" href="#__codelineno-14-27"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-14-28" name="__codelineno-14-28" href="#__codelineno-14-28"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-29" name="__codelineno-14-29" href="#__codelineno-14-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-14-30" name="__codelineno-14-30" href="#__codelineno-14-30"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-31" name="__codelineno-14-31" href="#__codelineno-14-31"></a>
<a id="__codelineno-14-32" name="__codelineno-14-32" href="#__codelineno-14-32"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-14-33" name="__codelineno-14-33" href="#__codelineno-14-33"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-34" name="__codelineno-14-34" href="#__codelineno-14-34"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-14-35" name="__codelineno-14-35" href="#__codelineno-14-35"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-14-36" name="__codelineno-14-36" href="#__codelineno-14-36"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-14-37" name="__codelineno-14-37" href="#__codelineno-14-37"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-14-38" name="__codelineno-14-38" href="#__codelineno-14-38"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-14-39" name="__codelineno-14-39" href="#__codelineno-14-39"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-40" name="__codelineno-14-40" href="#__codelineno-14-40"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-14-41" name="__codelineno-14-41" href="#__codelineno-14-41"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-14-42" name="__codelineno-14-42" href="#__codelineno-14-42"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-14-43" name="__codelineno-14-43" href="#__codelineno-14-43"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-14-44" name="__codelineno-14-44" href="#__codelineno-14-44"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-14-45" name="__codelineno-14-45" href="#__codelineno-14-45"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-46" name="__codelineno-14-46" href="#__codelineno-14-46"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-14-47" name="__codelineno-14-47" href="#__codelineno-14-47"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-14-48" name="__codelineno-14-48" href="#__codelineno-14-48"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-14-49" name="__codelineno-14-49" href="#__codelineno-14-49"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-14-50" name="__codelineno-14-50" href="#__codelineno-14-50"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-51" name="__codelineno-14-51" href="#__codelineno-14-51"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-14-52" name="__codelineno-14-52" href="#__codelineno-14-52"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-53" name="__codelineno-14-53" href="#__codelineno-14-53"></a>
<a id="__codelineno-14-54" name="__codelineno-14-54" href="#__codelineno-14-54"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-14-55" name="__codelineno-14-55" href="#__codelineno-14-55"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-56" name="__codelineno-14-56" href="#__codelineno-14-56"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-14-57" name="__codelineno-14-57" href="#__codelineno-14-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-58" name="__codelineno-14-58" href="#__codelineno-14-58"></a>
<a id="__codelineno-14-59" name="__codelineno-14-59" href="#__codelineno-14-59"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-14-60" name="__codelineno-14-60" href="#__codelineno-14-60"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-61" name="__codelineno-14-61" href="#__codelineno-14-61"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-14-62" name="__codelineno-14-62" href="#__codelineno-14-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-63" name="__codelineno-14-63" href="#__codelineno-14-63"></a>
<a id="__codelineno-14-64" name="__codelineno-14-64" href="#__codelineno-14-64"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-14-65" name="__codelineno-14-65" href="#__codelineno-14-65"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="kt">boolean</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-66" name="__codelineno-14-66" href="#__codelineno-14-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-14-67" name="__codelineno-14-67" href="#__codelineno-14-67"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-14-68" name="__codelineno-14-68" href="#__codelineno-14-68"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-14-69" name="__codelineno-14-69" href="#__codelineno-14-69"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-14-70" name="__codelineno-14-70" href="#__codelineno-14-70"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-71" name="__codelineno-14-71" href="#__codelineno-14-71"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-14-72" name="__codelineno-14-72" href="#__codelineno-14-72"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-14-73" name="__codelineno-14-73" href="#__codelineno-14-73"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">next</span><span class="p">;</span>
<a id="__codelineno-14-74" name="__codelineno-14-74" href="#__codelineno-14-74"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-75" name="__codelineno-14-75" href="#__codelineno-14-75"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-76" name="__codelineno-14-76" href="#__codelineno-14-76"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-77" name="__codelineno-14-77" href="#__codelineno-14-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-78" name="__codelineno-14-78" href="#__codelineno-14-78"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-14-79" name="__codelineno-14-79" href="#__codelineno-14-79"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-14-80" name="__codelineno-14-80" href="#__codelineno-14-80"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-81" name="__codelineno-14-81" href="#__codelineno-14-81"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-14-82" name="__codelineno-14-82" href="#__codelineno-14-82"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-14-83" name="__codelineno-14-83" href="#__codelineno-14-83"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">prev</span><span class="p">;</span>
<a id="__codelineno-14-84" name="__codelineno-14-84" href="#__codelineno-14-84"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-85" name="__codelineno-14-85" href="#__codelineno-14-85"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-86" name="__codelineno-14-86" href="#__codelineno-14-86"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-87" name="__codelineno-14-87" href="#__codelineno-14-87"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-88" name="__codelineno-14-88" href="#__codelineno-14-88"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-14-89" name="__codelineno-14-89" href="#__codelineno-14-89"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-90" name="__codelineno-14-90" href="#__codelineno-14-90"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-14-91" name="__codelineno-14-91" href="#__codelineno-14-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-14-92" name="__codelineno-14-92" href="#__codelineno-14-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-93" name="__codelineno-14-93" href="#__codelineno-14-93"></a>
<a id="__codelineno-14-94" name="__codelineno-14-94" href="#__codelineno-14-94"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-14-95" name="__codelineno-14-95" href="#__codelineno-14-95"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-96" name="__codelineno-14-96" href="#__codelineno-14-96"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-14-97" name="__codelineno-14-97" href="#__codelineno-14-97"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-98" name="__codelineno-14-98" href="#__codelineno-14-98"></a>
<a id="__codelineno-14-99" name="__codelineno-14-99" href="#__codelineno-14-99"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-14-100" name="__codelineno-14-100" href="#__codelineno-14-100"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-101" name="__codelineno-14-101" href="#__codelineno-14-101"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-14-102" name="__codelineno-14-102" href="#__codelineno-14-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-103" name="__codelineno-14-103" href="#__codelineno-14-103"></a>
<a id="__codelineno-14-104" name="__codelineno-14-104" href="#__codelineno-14-104"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-14-105" name="__codelineno-14-105" href="#__codelineno-14-105"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-106" name="__codelineno-14-106" href="#__codelineno-14-106"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-14-107" name="__codelineno-14-107" href="#__codelineno-14-107"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-14-108" name="__codelineno-14-108" href="#__codelineno-14-108"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-14-109" name="__codelineno-14-109" href="#__codelineno-14-109"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-110" name="__codelineno-14-110" href="#__codelineno-14-110"></a>
<a id="__codelineno-14-111" name="__codelineno-14-111" href="#__codelineno-14-111"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-14-112" name="__codelineno-14-112" href="#__codelineno-14-112"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-113" name="__codelineno-14-113" href="#__codelineno-14-113"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-14-114" name="__codelineno-14-114" href="#__codelineno-14-114"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-14-115" name="__codelineno-14-115" href="#__codelineno-14-115"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-14-116" name="__codelineno-14-116" href="#__codelineno-14-116"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-117" name="__codelineno-14-117" href="#__codelineno-14-117"></a>
<a id="__codelineno-14-118" name="__codelineno-14-118" href="#__codelineno-14-118"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-14-119" name="__codelineno-14-119" href="#__codelineno-14-119"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="nf">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-120" name="__codelineno-14-120" href="#__codelineno-14-120"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-14-121" name="__codelineno-14-121" href="#__codelineno-14-121"></a><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="o">[</span><span class="n">size</span><span class="p">()</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-14-122" name="__codelineno-14-122" href="#__codelineno-14-122"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="na">length</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-123" name="__codelineno-14-123" href="#__codelineno-14-123"></a><span class="w"> </span><span class="n">res</span><span class="o">[</span><span class="n">i</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-14-124" name="__codelineno-14-124" href="#__codelineno-14-124"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">next</span><span class="p">;</span>
<a id="__codelineno-14-125" name="__codelineno-14-125" href="#__codelineno-14-125"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-126" name="__codelineno-14-126" href="#__codelineno-14-126"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-14-127" name="__codelineno-14-127" href="#__codelineno-14-127"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-128" name="__codelineno-14-128" href="#__codelineno-14-128"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.cs</span><pre><span></span><code><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-15-2" name="__codelineno-15-2" href="#__codelineno-15-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-3" name="__codelineno-15-3" href="#__codelineno-15-3"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-15-4" name="__codelineno-15-4" href="#__codelineno-15-4"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用</span>
<a id="__codelineno-15-5" name="__codelineno-15-5" href="#__codelineno-15-5"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用</span>
<a id="__codelineno-15-6" name="__codelineno-15-6" href="#__codelineno-15-6"></a>
<a id="__codelineno-15-7" name="__codelineno-15-7" href="#__codelineno-15-7"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">ListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-8" name="__codelineno-15-8" href="#__codelineno-15-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-9" name="__codelineno-15-9" href="#__codelineno-15-9"></a><span class="w"> </span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-10" name="__codelineno-15-10" href="#__codelineno-15-10"></a><span class="w"> </span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-11" name="__codelineno-15-11" href="#__codelineno-15-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-12" name="__codelineno-15-12" href="#__codelineno-15-12"></a><span class="p">}</span>
<a id="__codelineno-15-13" name="__codelineno-15-13" href="#__codelineno-15-13"></a>
<a id="__codelineno-15-14" name="__codelineno-15-14" href="#__codelineno-15-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-15-15" name="__codelineno-15-15" href="#__codelineno-15-15"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-16" name="__codelineno-15-16" href="#__codelineno-15-16"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front, 尾节点 rear</span>
<a id="__codelineno-15-17" name="__codelineno-15-17" href="#__codelineno-15-17"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-15-18" name="__codelineno-15-18" href="#__codelineno-15-18"></a>
<a id="__codelineno-15-19" name="__codelineno-15-19" href="#__codelineno-15-19"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-20" name="__codelineno-15-20" href="#__codelineno-15-20"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-21" name="__codelineno-15-21" href="#__codelineno-15-21"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-22" name="__codelineno-15-22" href="#__codelineno-15-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-23" name="__codelineno-15-23" href="#__codelineno-15-23"></a>
<a id="__codelineno-15-24" name="__codelineno-15-24" href="#__codelineno-15-24"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-15-25" name="__codelineno-15-25" href="#__codelineno-15-25"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">Size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-26" name="__codelineno-15-26" href="#__codelineno-15-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-15-27" name="__codelineno-15-27" href="#__codelineno-15-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-28" name="__codelineno-15-28" href="#__codelineno-15-28"></a>
<a id="__codelineno-15-29" name="__codelineno-15-29" href="#__codelineno-15-29"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-15-30" name="__codelineno-15-30" href="#__codelineno-15-30"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="nf">IsEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-31" name="__codelineno-15-31" href="#__codelineno-15-31"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">Size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-15-32" name="__codelineno-15-32" href="#__codelineno-15-32"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-33" name="__codelineno-15-33" href="#__codelineno-15-33"></a>
<a id="__codelineno-15-34" name="__codelineno-15-34" href="#__codelineno-15-34"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-15-35" name="__codelineno-15-35" href="#__codelineno-15-35"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">Push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-36" name="__codelineno-15-36" href="#__codelineno-15-36"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-15-37" name="__codelineno-15-37" href="#__codelineno-15-37"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-15-38" name="__codelineno-15-38" href="#__codelineno-15-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-39" name="__codelineno-15-39" href="#__codelineno-15-39"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-15-40" name="__codelineno-15-40" href="#__codelineno-15-40"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-15-41" name="__codelineno-15-41" href="#__codelineno-15-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-42" name="__codelineno-15-42" href="#__codelineno-15-42"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-15-43" name="__codelineno-15-43" href="#__codelineno-15-43"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="nf">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-44" name="__codelineno-15-44" href="#__codelineno-15-44"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-15-45" name="__codelineno-15-45" href="#__codelineno-15-45"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-15-46" name="__codelineno-15-46" href="#__codelineno-15-46"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-15-47" name="__codelineno-15-47" href="#__codelineno-15-47"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点 </span>
<a id="__codelineno-15-48" name="__codelineno-15-48" href="#__codelineno-15-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-49" name="__codelineno-15-49" href="#__codelineno-15-49"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-15-50" name="__codelineno-15-50" href="#__codelineno-15-50"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-51" name="__codelineno-15-51" href="#__codelineno-15-51"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-15-52" name="__codelineno-15-52" href="#__codelineno-15-52"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-15-53" name="__codelineno-15-53" href="#__codelineno-15-53"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-15-54" name="__codelineno-15-54" href="#__codelineno-15-54"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-15-55" name="__codelineno-15-55" href="#__codelineno-15-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-56" name="__codelineno-15-56" href="#__codelineno-15-56"></a>
<a id="__codelineno-15-57" name="__codelineno-15-57" href="#__codelineno-15-57"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-15-58" name="__codelineno-15-58" href="#__codelineno-15-58"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-59" name="__codelineno-15-59" href="#__codelineno-15-59"></a>
<a id="__codelineno-15-60" name="__codelineno-15-60" href="#__codelineno-15-60"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-15-61" name="__codelineno-15-61" href="#__codelineno-15-61"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">PushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-62" name="__codelineno-15-62" href="#__codelineno-15-62"></a><span class="w"> </span><span class="n">Push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="k">true</span><span class="p">);</span>
<a id="__codelineno-15-63" name="__codelineno-15-63" href="#__codelineno-15-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-64" name="__codelineno-15-64" href="#__codelineno-15-64"></a>
<a id="__codelineno-15-65" name="__codelineno-15-65" href="#__codelineno-15-65"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-15-66" name="__codelineno-15-66" href="#__codelineno-15-66"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">PushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-67" name="__codelineno-15-67" href="#__codelineno-15-67"></a><span class="w"> </span><span class="n">Push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="k">false</span><span class="p">);</span>
<a id="__codelineno-15-68" name="__codelineno-15-68" href="#__codelineno-15-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-69" name="__codelineno-15-69" href="#__codelineno-15-69"></a>
<a id="__codelineno-15-70" name="__codelineno-15-70" href="#__codelineno-15-70"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-15-71" name="__codelineno-15-71" href="#__codelineno-15-71"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">Pop</span><span class="p">(</span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-72" name="__codelineno-15-72" href="#__codelineno-15-72"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span>
<a id="__codelineno-15-73" name="__codelineno-15-73" href="#__codelineno-15-73"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">Exception</span><span class="p">();</span>
<a id="__codelineno-15-74" name="__codelineno-15-74" href="#__codelineno-15-74"></a><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-75" name="__codelineno-15-75" href="#__codelineno-15-75"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-15-76" name="__codelineno-15-76" href="#__codelineno-15-76"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-77" name="__codelineno-15-77" href="#__codelineno-15-77"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">?.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-15-78" name="__codelineno-15-78" href="#__codelineno-15-78"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-15-79" name="__codelineno-15-79" href="#__codelineno-15-79"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">?.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-15-80" name="__codelineno-15-80" href="#__codelineno-15-80"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-81" name="__codelineno-15-81" href="#__codelineno-15-81"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-82" name="__codelineno-15-82" href="#__codelineno-15-82"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-83" name="__codelineno-15-83" href="#__codelineno-15-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-84" name="__codelineno-15-84" href="#__codelineno-15-84"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-15-85" name="__codelineno-15-85" href="#__codelineno-15-85"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-86" name="__codelineno-15-86" href="#__codelineno-15-86"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-15-87" name="__codelineno-15-87" href="#__codelineno-15-87"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-88" name="__codelineno-15-88" href="#__codelineno-15-88"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">?.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-15-89" name="__codelineno-15-89" href="#__codelineno-15-89"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-15-90" name="__codelineno-15-90" href="#__codelineno-15-90"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">?.</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-15-91" name="__codelineno-15-91" href="#__codelineno-15-91"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-92" name="__codelineno-15-92" href="#__codelineno-15-92"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-93" name="__codelineno-15-93" href="#__codelineno-15-93"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-15-94" name="__codelineno-15-94" href="#__codelineno-15-94"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-95" name="__codelineno-15-95" href="#__codelineno-15-95"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-15-96" name="__codelineno-15-96" href="#__codelineno-15-96"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-97" name="__codelineno-15-97" href="#__codelineno-15-97"></a>
<a id="__codelineno-15-98" name="__codelineno-15-98" href="#__codelineno-15-98"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-15-99" name="__codelineno-15-99" href="#__codelineno-15-99"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-100" name="__codelineno-15-100" href="#__codelineno-15-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-101" name="__codelineno-15-101" href="#__codelineno-15-101"></a>
<a id="__codelineno-15-102" name="__codelineno-15-102" href="#__codelineno-15-102"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-15-103" name="__codelineno-15-103" href="#__codelineno-15-103"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">PopFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-104" name="__codelineno-15-104" href="#__codelineno-15-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">Pop</span><span class="p">(</span><span class="k">true</span><span class="p">);</span>
<a id="__codelineno-15-105" name="__codelineno-15-105" href="#__codelineno-15-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-106" name="__codelineno-15-106" href="#__codelineno-15-106"></a>
<a id="__codelineno-15-107" name="__codelineno-15-107" href="#__codelineno-15-107"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-15-108" name="__codelineno-15-108" href="#__codelineno-15-108"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">PopLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-109" name="__codelineno-15-109" href="#__codelineno-15-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">Pop</span><span class="p">(</span><span class="k">false</span><span class="p">);</span>
<a id="__codelineno-15-110" name="__codelineno-15-110" href="#__codelineno-15-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-111" name="__codelineno-15-111" href="#__codelineno-15-111"></a>
<a id="__codelineno-15-112" name="__codelineno-15-112" href="#__codelineno-15-112"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-15-113" name="__codelineno-15-113" href="#__codelineno-15-113"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">PeekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-114" name="__codelineno-15-114" href="#__codelineno-15-114"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span>
<a id="__codelineno-15-115" name="__codelineno-15-115" href="#__codelineno-15-115"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">Exception</span><span class="p">();</span>
<a id="__codelineno-15-116" name="__codelineno-15-116" href="#__codelineno-15-116"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">front</span><span class="o">?.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-117" name="__codelineno-15-117" href="#__codelineno-15-117"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-118" name="__codelineno-15-118" href="#__codelineno-15-118"></a>
<a id="__codelineno-15-119" name="__codelineno-15-119" href="#__codelineno-15-119"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-15-120" name="__codelineno-15-120" href="#__codelineno-15-120"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">PeekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-121" name="__codelineno-15-121" href="#__codelineno-15-121"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span>
<a id="__codelineno-15-122" name="__codelineno-15-122" href="#__codelineno-15-122"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">Exception</span><span class="p">();</span>
<a id="__codelineno-15-123" name="__codelineno-15-123" href="#__codelineno-15-123"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">rear</span><span class="o">?.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-124" name="__codelineno-15-124" href="#__codelineno-15-124"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-125" name="__codelineno-15-125" href="#__codelineno-15-125"></a>
<a id="__codelineno-15-126" name="__codelineno-15-126" href="#__codelineno-15-126"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-15-127" name="__codelineno-15-127" href="#__codelineno-15-127"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="p">[]</span><span class="w"> </span><span class="n">ToArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-128" name="__codelineno-15-128" href="#__codelineno-15-128"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-15-129" name="__codelineno-15-129" href="#__codelineno-15-129"></a><span class="w"> </span><span class="kt">int?</span><span class="p">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int?</span><span class="p">[</span><span class="n">Size</span><span class="p">()];</span>
<a id="__codelineno-15-130" name="__codelineno-15-130" href="#__codelineno-15-130"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">Length</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-131" name="__codelineno-15-131" href="#__codelineno-15-131"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">?.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-15-132" name="__codelineno-15-132" href="#__codelineno-15-132"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">?.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-15-133" name="__codelineno-15-133" href="#__codelineno-15-133"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-134" name="__codelineno-15-134" href="#__codelineno-15-134"></a>
<a id="__codelineno-15-135" name="__codelineno-15-135" href="#__codelineno-15-135"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-15-136" name="__codelineno-15-136" href="#__codelineno-15-136"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-137" name="__codelineno-15-137" href="#__codelineno-15-137"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.go</span><pre><span></span><code><a id="__codelineno-16-1" name="__codelineno-16-1" href="#__codelineno-16-1"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-16-2" name="__codelineno-16-2" href="#__codelineno-16-2"></a><span class="kd">type</span><span class="w"> </span><span class="nx">linkedListDeque</span><span class="w"> </span><span class="kd">struct</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-3" name="__codelineno-16-3" href="#__codelineno-16-3"></a><span class="w"> </span><span class="c1">// 使用内置包 list</span>
<a id="__codelineno-16-4" name="__codelineno-16-4" href="#__codelineno-16-4"></a><span class="w"> </span><span class="nx">data</span><span class="w"> </span><span class="o">*</span><span class="nx">list</span><span class="p">.</span><span class="nx">List</span>
<a id="__codelineno-16-5" name="__codelineno-16-5" href="#__codelineno-16-5"></a><span class="p">}</span>
<a id="__codelineno-16-6" name="__codelineno-16-6" href="#__codelineno-16-6"></a>
<a id="__codelineno-16-7" name="__codelineno-16-7" href="#__codelineno-16-7"></a><span class="cm">/* 初始化双端队列 */</span>
<a id="__codelineno-16-8" name="__codelineno-16-8" href="#__codelineno-16-8"></a><span class="kd">func</span><span class="w"> </span><span class="nx">newLinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-9" name="__codelineno-16-9" href="#__codelineno-16-9"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">&amp;</span><span class="nx">linkedListDeque</span><span class="p">{</span>
<a id="__codelineno-16-10" name="__codelineno-16-10" href="#__codelineno-16-10"></a><span class="w"> </span><span class="nx">data</span><span class="p">:</span><span class="w"> </span><span class="nx">list</span><span class="p">.</span><span class="nx">New</span><span class="p">(),</span>
<a id="__codelineno-16-11" name="__codelineno-16-11" href="#__codelineno-16-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-12" name="__codelineno-16-12" href="#__codelineno-16-12"></a><span class="p">}</span>
<a id="__codelineno-16-13" name="__codelineno-16-13" href="#__codelineno-16-13"></a>
<a id="__codelineno-16-14" name="__codelineno-16-14" href="#__codelineno-16-14"></a><span class="cm">/* 队首元素入队 */</span>
<a id="__codelineno-16-15" name="__codelineno-16-15" href="#__codelineno-16-15"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">value</span><span class="w"> </span><span class="kt">any</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-16" name="__codelineno-16-16" href="#__codelineno-16-16"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">PushFront</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span>
<a id="__codelineno-16-17" name="__codelineno-16-17" href="#__codelineno-16-17"></a><span class="p">}</span>
<a id="__codelineno-16-18" name="__codelineno-16-18" href="#__codelineno-16-18"></a>
<a id="__codelineno-16-19" name="__codelineno-16-19" href="#__codelineno-16-19"></a><span class="cm">/* 队尾元素入队 */</span>
<a id="__codelineno-16-20" name="__codelineno-16-20" href="#__codelineno-16-20"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">value</span><span class="w"> </span><span class="kt">any</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-21" name="__codelineno-16-21" href="#__codelineno-16-21"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span>
<a id="__codelineno-16-22" name="__codelineno-16-22" href="#__codelineno-16-22"></a><span class="p">}</span>
<a id="__codelineno-16-23" name="__codelineno-16-23" href="#__codelineno-16-23"></a>
<a id="__codelineno-16-24" name="__codelineno-16-24" href="#__codelineno-16-24"></a><span class="cm">/* 队首元素出队 */</span>
<a id="__codelineno-16-25" name="__codelineno-16-25" href="#__codelineno-16-25"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-26" name="__codelineno-16-26" href="#__codelineno-16-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-27" name="__codelineno-16-27" href="#__codelineno-16-27"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-16-28" name="__codelineno-16-28" href="#__codelineno-16-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-29" name="__codelineno-16-29" href="#__codelineno-16-29"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span>
<a id="__codelineno-16-30" name="__codelineno-16-30" href="#__codelineno-16-30"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span>
<a id="__codelineno-16-31" name="__codelineno-16-31" href="#__codelineno-16-31"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-16-32" name="__codelineno-16-32" href="#__codelineno-16-32"></a><span class="p">}</span>
<a id="__codelineno-16-33" name="__codelineno-16-33" href="#__codelineno-16-33"></a>
<a id="__codelineno-16-34" name="__codelineno-16-34" href="#__codelineno-16-34"></a><span class="cm">/* 队尾元素出队 */</span>
<a id="__codelineno-16-35" name="__codelineno-16-35" href="#__codelineno-16-35"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-36" name="__codelineno-16-36" href="#__codelineno-16-36"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-37" name="__codelineno-16-37" href="#__codelineno-16-37"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-16-38" name="__codelineno-16-38" href="#__codelineno-16-38"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-39" name="__codelineno-16-39" href="#__codelineno-16-39"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Back</span><span class="p">()</span>
<a id="__codelineno-16-40" name="__codelineno-16-40" href="#__codelineno-16-40"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span>
<a id="__codelineno-16-41" name="__codelineno-16-41" href="#__codelineno-16-41"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-16-42" name="__codelineno-16-42" href="#__codelineno-16-42"></a><span class="p">}</span>
<a id="__codelineno-16-43" name="__codelineno-16-43" href="#__codelineno-16-43"></a>
<a id="__codelineno-16-44" name="__codelineno-16-44" href="#__codelineno-16-44"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-16-45" name="__codelineno-16-45" href="#__codelineno-16-45"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-46" name="__codelineno-16-46" href="#__codelineno-16-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-47" name="__codelineno-16-47" href="#__codelineno-16-47"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-16-48" name="__codelineno-16-48" href="#__codelineno-16-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-49" name="__codelineno-16-49" href="#__codelineno-16-49"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span>
<a id="__codelineno-16-50" name="__codelineno-16-50" href="#__codelineno-16-50"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-16-51" name="__codelineno-16-51" href="#__codelineno-16-51"></a><span class="p">}</span>
<a id="__codelineno-16-52" name="__codelineno-16-52" href="#__codelineno-16-52"></a>
<a id="__codelineno-16-53" name="__codelineno-16-53" href="#__codelineno-16-53"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-16-54" name="__codelineno-16-54" href="#__codelineno-16-54"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-55" name="__codelineno-16-55" href="#__codelineno-16-55"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-56" name="__codelineno-16-56" href="#__codelineno-16-56"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-16-57" name="__codelineno-16-57" href="#__codelineno-16-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-58" name="__codelineno-16-58" href="#__codelineno-16-58"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Back</span><span class="p">()</span>
<a id="__codelineno-16-59" name="__codelineno-16-59" href="#__codelineno-16-59"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-16-60" name="__codelineno-16-60" href="#__codelineno-16-60"></a><span class="p">}</span>
<a id="__codelineno-16-61" name="__codelineno-16-61" href="#__codelineno-16-61"></a>
<a id="__codelineno-16-62" name="__codelineno-16-62" href="#__codelineno-16-62"></a><span class="cm">/* 获取队列的长度 */</span>
<a id="__codelineno-16-63" name="__codelineno-16-63" href="#__codelineno-16-63"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-64" name="__codelineno-16-64" href="#__codelineno-16-64"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span>
<a id="__codelineno-16-65" name="__codelineno-16-65" href="#__codelineno-16-65"></a><span class="p">}</span>
<a id="__codelineno-16-66" name="__codelineno-16-66" href="#__codelineno-16-66"></a>
<a id="__codelineno-16-67" name="__codelineno-16-67" href="#__codelineno-16-67"></a><span class="cm">/* 判断队列是否为空 */</span>
<a id="__codelineno-16-68" name="__codelineno-16-68" href="#__codelineno-16-68"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-69" name="__codelineno-16-69" href="#__codelineno-16-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
<a id="__codelineno-16-70" name="__codelineno-16-70" href="#__codelineno-16-70"></a><span class="p">}</span>
<a id="__codelineno-16-71" name="__codelineno-16-71" href="#__codelineno-16-71"></a>
<a id="__codelineno-16-72" name="__codelineno-16-72" href="#__codelineno-16-72"></a><span class="cm">/* 获取 List 用于打印 */</span>
<a id="__codelineno-16-73" name="__codelineno-16-73" href="#__codelineno-16-73"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">toList</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">list</span><span class="p">.</span><span class="nx">List</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-74" name="__codelineno-16-74" href="#__codelineno-16-74"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span>
<a id="__codelineno-16-75" name="__codelineno-16-75" href="#__codelineno-16-75"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.swift</span><pre><span></span><code><a id="__codelineno-17-1" name="__codelineno-17-1" href="#__codelineno-17-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-17-2" name="__codelineno-17-2" href="#__codelineno-17-2"></a><span class="kd">class</span> <span class="nc">ListNode</span> <span class="p">{</span>
<a id="__codelineno-17-3" name="__codelineno-17-3" href="#__codelineno-17-3"></a> <span class="kd">var</span> <span class="nv">val</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 节点值</span>
<a id="__codelineno-17-4" name="__codelineno-17-4" href="#__codelineno-17-4"></a> <span class="kd">var</span> <span class="nv">next</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 后继节点引用</span>
<a id="__codelineno-17-5" name="__codelineno-17-5" href="#__codelineno-17-5"></a> <span class="kr">weak</span> <span class="kd">var</span> <span class="nv">prev</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 前驱节点引用</span>
<a id="__codelineno-17-6" name="__codelineno-17-6" href="#__codelineno-17-6"></a>
<a id="__codelineno-17-7" name="__codelineno-17-7" href="#__codelineno-17-7"></a> <span class="kd">init</span><span class="p">(</span><span class="n">val</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-17-8" name="__codelineno-17-8" href="#__codelineno-17-8"></a> <span class="kc">self</span><span class="p">.</span><span class="n">val</span> <span class="p">=</span> <span class="n">val</span>
<a id="__codelineno-17-9" name="__codelineno-17-9" href="#__codelineno-17-9"></a> <span class="p">}</span>
<a id="__codelineno-17-10" name="__codelineno-17-10" href="#__codelineno-17-10"></a><span class="p">}</span>
<a id="__codelineno-17-11" name="__codelineno-17-11" href="#__codelineno-17-11"></a>
<a id="__codelineno-17-12" name="__codelineno-17-12" href="#__codelineno-17-12"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-17-13" name="__codelineno-17-13" href="#__codelineno-17-13"></a><span class="kd">class</span> <span class="nc">LinkedListDeque</span> <span class="p">{</span>
<a id="__codelineno-17-14" name="__codelineno-17-14" href="#__codelineno-17-14"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">front</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 头节点 front</span>
<a id="__codelineno-17-15" name="__codelineno-17-15" href="#__codelineno-17-15"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">rear</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 尾节点 rear</span>
<a id="__codelineno-17-16" name="__codelineno-17-16" href="#__codelineno-17-16"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">queSize</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 双向队列的长度</span>
<a id="__codelineno-17-17" name="__codelineno-17-17" href="#__codelineno-17-17"></a>
<a id="__codelineno-17-18" name="__codelineno-17-18" href="#__codelineno-17-18"></a> <span class="kd">init</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-17-19" name="__codelineno-17-19" href="#__codelineno-17-19"></a> <span class="n">queSize</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-17-20" name="__codelineno-17-20" href="#__codelineno-17-20"></a> <span class="p">}</span>
<a id="__codelineno-17-21" name="__codelineno-17-21" href="#__codelineno-17-21"></a>
<a id="__codelineno-17-22" name="__codelineno-17-22" href="#__codelineno-17-22"></a> <span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-17-23" name="__codelineno-17-23" href="#__codelineno-17-23"></a> <span class="kd">func</span> <span class="nf">size</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-17-24" name="__codelineno-17-24" href="#__codelineno-17-24"></a> <span class="n">queSize</span>
<a id="__codelineno-17-25" name="__codelineno-17-25" href="#__codelineno-17-25"></a> <span class="p">}</span>
<a id="__codelineno-17-26" name="__codelineno-17-26" href="#__codelineno-17-26"></a>
<a id="__codelineno-17-27" name="__codelineno-17-27" href="#__codelineno-17-27"></a> <span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-17-28" name="__codelineno-17-28" href="#__codelineno-17-28"></a> <span class="kd">func</span> <span class="nf">isEmpty</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Bool</span> <span class="p">{</span>
<a id="__codelineno-17-29" name="__codelineno-17-29" href="#__codelineno-17-29"></a> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="mi">0</span>
<a id="__codelineno-17-30" name="__codelineno-17-30" href="#__codelineno-17-30"></a> <span class="p">}</span>
<a id="__codelineno-17-31" name="__codelineno-17-31" href="#__codelineno-17-31"></a>
<a id="__codelineno-17-32" name="__codelineno-17-32" href="#__codelineno-17-32"></a> <span class="cm">/* 入队操作 */</span>
<a id="__codelineno-17-33" name="__codelineno-17-33" href="#__codelineno-17-33"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="nb">Bool</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-17-34" name="__codelineno-17-34" href="#__codelineno-17-34"></a> <span class="kd">let</span> <span class="nv">node</span> <span class="p">=</span> <span class="n">ListNode</span><span class="p">(</span><span class="n">val</span><span class="p">:</span> <span class="n">num</span><span class="p">)</span>
<a id="__codelineno-17-35" name="__codelineno-17-35" href="#__codelineno-17-35"></a> <span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-17-36" name="__codelineno-17-36" href="#__codelineno-17-36"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-17-37" name="__codelineno-17-37" href="#__codelineno-17-37"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-17-38" name="__codelineno-17-38" href="#__codelineno-17-38"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-17-39" name="__codelineno-17-39" href="#__codelineno-17-39"></a> <span class="p">}</span>
<a id="__codelineno-17-40" name="__codelineno-17-40" href="#__codelineno-17-40"></a> <span class="c1">// 队首入队操作</span>
<a id="__codelineno-17-41" name="__codelineno-17-41" href="#__codelineno-17-41"></a> <span class="k">else</span> <span class="k">if</span> <span class="n">isFront</span> <span class="p">{</span>
<a id="__codelineno-17-42" name="__codelineno-17-42" href="#__codelineno-17-42"></a> <span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-17-43" name="__codelineno-17-43" href="#__codelineno-17-43"></a> <span class="n">front</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-17-44" name="__codelineno-17-44" href="#__codelineno-17-44"></a> <span class="n">node</span><span class="p">.</span><span class="n">next</span> <span class="p">=</span> <span class="n">front</span>
<a id="__codelineno-17-45" name="__codelineno-17-45" href="#__codelineno-17-45"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">node</span> <span class="c1">// 更新头节点</span>
<a id="__codelineno-17-46" name="__codelineno-17-46" href="#__codelineno-17-46"></a> <span class="p">}</span>
<a id="__codelineno-17-47" name="__codelineno-17-47" href="#__codelineno-17-47"></a> <span class="c1">// 队尾入队操作</span>
<a id="__codelineno-17-48" name="__codelineno-17-48" href="#__codelineno-17-48"></a> <span class="k">else</span> <span class="p">{</span>
<a id="__codelineno-17-49" name="__codelineno-17-49" href="#__codelineno-17-49"></a> <span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-17-50" name="__codelineno-17-50" href="#__codelineno-17-50"></a> <span class="n">rear</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-17-51" name="__codelineno-17-51" href="#__codelineno-17-51"></a> <span class="n">node</span><span class="p">.</span><span class="n">prev</span> <span class="p">=</span> <span class="n">rear</span>
<a id="__codelineno-17-52" name="__codelineno-17-52" href="#__codelineno-17-52"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">node</span> <span class="c1">// 更新尾节点</span>
<a id="__codelineno-17-53" name="__codelineno-17-53" href="#__codelineno-17-53"></a> <span class="p">}</span>
<a id="__codelineno-17-54" name="__codelineno-17-54" href="#__codelineno-17-54"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span> <span class="c1">// 更新队列长度</span>
<a id="__codelineno-17-55" name="__codelineno-17-55" href="#__codelineno-17-55"></a> <span class="p">}</span>
<a id="__codelineno-17-56" name="__codelineno-17-56" href="#__codelineno-17-56"></a>
<a id="__codelineno-17-57" name="__codelineno-17-57" href="#__codelineno-17-57"></a> <span class="cm">/* 队首入队 */</span>
<a id="__codelineno-17-58" name="__codelineno-17-58" href="#__codelineno-17-58"></a> <span class="kd">func</span> <span class="nf">pushFirst</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-17-59" name="__codelineno-17-59" href="#__codelineno-17-59"></a> <span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="n">num</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="kc">true</span><span class="p">)</span>
<a id="__codelineno-17-60" name="__codelineno-17-60" href="#__codelineno-17-60"></a> <span class="p">}</span>
<a id="__codelineno-17-61" name="__codelineno-17-61" href="#__codelineno-17-61"></a>
<a id="__codelineno-17-62" name="__codelineno-17-62" href="#__codelineno-17-62"></a> <span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-17-63" name="__codelineno-17-63" href="#__codelineno-17-63"></a> <span class="kd">func</span> <span class="nf">pushLast</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-17-64" name="__codelineno-17-64" href="#__codelineno-17-64"></a> <span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="n">num</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="kc">false</span><span class="p">)</span>
<a id="__codelineno-17-65" name="__codelineno-17-65" href="#__codelineno-17-65"></a> <span class="p">}</span>
<a id="__codelineno-17-66" name="__codelineno-17-66" href="#__codelineno-17-66"></a>
<a id="__codelineno-17-67" name="__codelineno-17-67" href="#__codelineno-17-67"></a> <span class="cm">/* 出队操作 */</span>
<a id="__codelineno-17-68" name="__codelineno-17-68" href="#__codelineno-17-68"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="nb">Bool</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-17-69" name="__codelineno-17-69" href="#__codelineno-17-69"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-17-70" name="__codelineno-17-70" href="#__codelineno-17-70"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-17-71" name="__codelineno-17-71" href="#__codelineno-17-71"></a> <span class="p">}</span>
<a id="__codelineno-17-72" name="__codelineno-17-72" href="#__codelineno-17-72"></a> <span class="kd">let</span> <span class="nv">val</span><span class="p">:</span> <span class="nb">Int</span>
<a id="__codelineno-17-73" name="__codelineno-17-73" href="#__codelineno-17-73"></a> <span class="c1">// 队首出队操作</span>
<a id="__codelineno-17-74" name="__codelineno-17-74" href="#__codelineno-17-74"></a> <span class="k">if</span> <span class="n">isFront</span> <span class="p">{</span>
<a id="__codelineno-17-75" name="__codelineno-17-75" href="#__codelineno-17-75"></a> <span class="n">val</span> <span class="p">=</span> <span class="n">front</span><span class="p">!.</span><span class="n">val</span> <span class="c1">// 暂存头节点值</span>
<a id="__codelineno-17-76" name="__codelineno-17-76" href="#__codelineno-17-76"></a> <span class="c1">// 删除头节点</span>
<a id="__codelineno-17-77" name="__codelineno-17-77" href="#__codelineno-17-77"></a> <span class="kd">let</span> <span class="nv">fNext</span> <span class="p">=</span> <span class="n">front</span><span class="p">?.</span><span class="n">next</span>
<a id="__codelineno-17-78" name="__codelineno-17-78" href="#__codelineno-17-78"></a> <span class="k">if</span> <span class="n">fNext</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
<a id="__codelineno-17-79" name="__codelineno-17-79" href="#__codelineno-17-79"></a> <span class="n">fNext</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-17-80" name="__codelineno-17-80" href="#__codelineno-17-80"></a> <span class="n">front</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-17-81" name="__codelineno-17-81" href="#__codelineno-17-81"></a> <span class="p">}</span>
<a id="__codelineno-17-82" name="__codelineno-17-82" href="#__codelineno-17-82"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">fNext</span> <span class="c1">// 更新头节点</span>
<a id="__codelineno-17-83" name="__codelineno-17-83" href="#__codelineno-17-83"></a> <span class="p">}</span>
<a id="__codelineno-17-84" name="__codelineno-17-84" href="#__codelineno-17-84"></a> <span class="c1">// 队尾出队操作</span>
<a id="__codelineno-17-85" name="__codelineno-17-85" href="#__codelineno-17-85"></a> <span class="k">else</span> <span class="p">{</span>
<a id="__codelineno-17-86" name="__codelineno-17-86" href="#__codelineno-17-86"></a> <span class="n">val</span> <span class="p">=</span> <span class="n">rear</span><span class="p">!.</span><span class="n">val</span> <span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-17-87" name="__codelineno-17-87" href="#__codelineno-17-87"></a> <span class="c1">// 删除尾节点</span>
<a id="__codelineno-17-88" name="__codelineno-17-88" href="#__codelineno-17-88"></a> <span class="kd">let</span> <span class="nv">rPrev</span> <span class="p">=</span> <span class="n">rear</span><span class="p">?.</span><span class="n">prev</span>
<a id="__codelineno-17-89" name="__codelineno-17-89" href="#__codelineno-17-89"></a> <span class="k">if</span> <span class="n">rPrev</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
<a id="__codelineno-17-90" name="__codelineno-17-90" href="#__codelineno-17-90"></a> <span class="n">rPrev</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-17-91" name="__codelineno-17-91" href="#__codelineno-17-91"></a> <span class="n">rear</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-17-92" name="__codelineno-17-92" href="#__codelineno-17-92"></a> <span class="p">}</span>
<a id="__codelineno-17-93" name="__codelineno-17-93" href="#__codelineno-17-93"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">rPrev</span> <span class="c1">// 更新尾节点</span>
<a id="__codelineno-17-94" name="__codelineno-17-94" href="#__codelineno-17-94"></a> <span class="p">}</span>
<a id="__codelineno-17-95" name="__codelineno-17-95" href="#__codelineno-17-95"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span> <span class="c1">// 更新队列长度</span>
<a id="__codelineno-17-96" name="__codelineno-17-96" href="#__codelineno-17-96"></a> <span class="k">return</span> <span class="n">val</span>
<a id="__codelineno-17-97" name="__codelineno-17-97" href="#__codelineno-17-97"></a> <span class="p">}</span>
<a id="__codelineno-17-98" name="__codelineno-17-98" href="#__codelineno-17-98"></a>
<a id="__codelineno-17-99" name="__codelineno-17-99" href="#__codelineno-17-99"></a> <span class="cm">/* 队首出队 */</span>
<a id="__codelineno-17-100" name="__codelineno-17-100" href="#__codelineno-17-100"></a> <span class="kd">func</span> <span class="nf">popFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-17-101" name="__codelineno-17-101" href="#__codelineno-17-101"></a> <span class="n">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="kc">true</span><span class="p">)</span>
<a id="__codelineno-17-102" name="__codelineno-17-102" href="#__codelineno-17-102"></a> <span class="p">}</span>
<a id="__codelineno-17-103" name="__codelineno-17-103" href="#__codelineno-17-103"></a>
<a id="__codelineno-17-104" name="__codelineno-17-104" href="#__codelineno-17-104"></a> <span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-17-105" name="__codelineno-17-105" href="#__codelineno-17-105"></a> <span class="kd">func</span> <span class="nf">popLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-17-106" name="__codelineno-17-106" href="#__codelineno-17-106"></a> <span class="n">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="kc">false</span><span class="p">)</span>
<a id="__codelineno-17-107" name="__codelineno-17-107" href="#__codelineno-17-107"></a> <span class="p">}</span>
<a id="__codelineno-17-108" name="__codelineno-17-108" href="#__codelineno-17-108"></a>
<a id="__codelineno-17-109" name="__codelineno-17-109" href="#__codelineno-17-109"></a> <span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-17-110" name="__codelineno-17-110" href="#__codelineno-17-110"></a> <span class="kd">func</span> <span class="nf">peekFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span><span class="p">?</span> <span class="p">{</span>
<a id="__codelineno-17-111" name="__codelineno-17-111" href="#__codelineno-17-111"></a> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">?</span> <span class="kc">nil</span> <span class="p">:</span> <span class="n">front</span><span class="p">?.</span><span class="n">val</span>
<a id="__codelineno-17-112" name="__codelineno-17-112" href="#__codelineno-17-112"></a> <span class="p">}</span>
<a id="__codelineno-17-113" name="__codelineno-17-113" href="#__codelineno-17-113"></a>
<a id="__codelineno-17-114" name="__codelineno-17-114" href="#__codelineno-17-114"></a> <span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-17-115" name="__codelineno-17-115" href="#__codelineno-17-115"></a> <span class="kd">func</span> <span class="nf">peekLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span><span class="p">?</span> <span class="p">{</span>
<a id="__codelineno-17-116" name="__codelineno-17-116" href="#__codelineno-17-116"></a> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">?</span> <span class="kc">nil</span> <span class="p">:</span> <span class="n">rear</span><span class="p">?.</span><span class="n">val</span>
<a id="__codelineno-17-117" name="__codelineno-17-117" href="#__codelineno-17-117"></a> <span class="p">}</span>
<a id="__codelineno-17-118" name="__codelineno-17-118" href="#__codelineno-17-118"></a>
<a id="__codelineno-17-119" name="__codelineno-17-119" href="#__codelineno-17-119"></a> <span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-17-120" name="__codelineno-17-120" href="#__codelineno-17-120"></a> <span class="kd">func</span> <span class="nf">toArray</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-17-121" name="__codelineno-17-121" href="#__codelineno-17-121"></a> <span class="kd">var</span> <span class="nv">node</span> <span class="p">=</span> <span class="n">front</span>
<a id="__codelineno-17-122" name="__codelineno-17-122" href="#__codelineno-17-122"></a> <span class="kd">var</span> <span class="nv">res</span> <span class="p">=</span> <span class="nb">Array</span><span class="p">(</span><span class="n">repeating</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="bp">count</span><span class="p">:</span> <span class="n">size</span><span class="p">())</span>
<a id="__codelineno-17-123" name="__codelineno-17-123" href="#__codelineno-17-123"></a> <span class="k">for</span> <span class="n">i</span> <span class="k">in</span> <span class="n">res</span><span class="p">.</span><span class="bp">indices</span> <span class="p">{</span>
<a id="__codelineno-17-124" name="__codelineno-17-124" href="#__codelineno-17-124"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="p">=</span> <span class="n">node</span><span class="p">!.</span><span class="n">val</span>
<a id="__codelineno-17-125" name="__codelineno-17-125" href="#__codelineno-17-125"></a> <span class="n">node</span> <span class="p">=</span> <span class="n">node</span><span class="p">?.</span><span class="n">next</span>
<a id="__codelineno-17-126" name="__codelineno-17-126" href="#__codelineno-17-126"></a> <span class="p">}</span>
<a id="__codelineno-17-127" name="__codelineno-17-127" href="#__codelineno-17-127"></a> <span class="k">return</span> <span class="n">res</span>
<a id="__codelineno-17-128" name="__codelineno-17-128" href="#__codelineno-17-128"></a> <span class="p">}</span>
<a id="__codelineno-17-129" name="__codelineno-17-129" href="#__codelineno-17-129"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.js</span><pre><span></span><code><a id="__codelineno-18-1" name="__codelineno-18-1" href="#__codelineno-18-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-18-2" name="__codelineno-18-2" href="#__codelineno-18-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-3" name="__codelineno-18-3" href="#__codelineno-18-3"></a><span class="w"> </span><span class="nx">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用 (指针)</span>
<a id="__codelineno-18-4" name="__codelineno-18-4" href="#__codelineno-18-4"></a><span class="w"> </span><span class="nx">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用 (指针)</span>
<a id="__codelineno-18-5" name="__codelineno-18-5" href="#__codelineno-18-5"></a><span class="w"> </span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-18-6" name="__codelineno-18-6" href="#__codelineno-18-6"></a>
<a id="__codelineno-18-7" name="__codelineno-18-7" href="#__codelineno-18-7"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-8" name="__codelineno-18-8" href="#__codelineno-18-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-18-9" name="__codelineno-18-9" href="#__codelineno-18-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-10" name="__codelineno-18-10" href="#__codelineno-18-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-11" name="__codelineno-18-11" href="#__codelineno-18-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-12" name="__codelineno-18-12" href="#__codelineno-18-12"></a><span class="p">}</span>
<a id="__codelineno-18-13" name="__codelineno-18-13" href="#__codelineno-18-13"></a>
<a id="__codelineno-18-14" name="__codelineno-18-14" href="#__codelineno-18-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-18-15" name="__codelineno-18-15" href="#__codelineno-18-15"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-16" name="__codelineno-18-16" href="#__codelineno-18-16"></a><span class="w"> </span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-18-17" name="__codelineno-18-17" href="#__codelineno-18-17"></a><span class="w"> </span><span class="err">#</span><span class="nx">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-18-18" name="__codelineno-18-18" href="#__codelineno-18-18"></a><span class="w"> </span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-18-19" name="__codelineno-18-19" href="#__codelineno-18-19"></a>
<a id="__codelineno-18-20" name="__codelineno-18-20" href="#__codelineno-18-20"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-21" name="__codelineno-18-21" href="#__codelineno-18-21"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-22" name="__codelineno-18-22" href="#__codelineno-18-22"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-23" name="__codelineno-18-23" href="#__codelineno-18-23"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-18-24" name="__codelineno-18-24" href="#__codelineno-18-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-25" name="__codelineno-18-25" href="#__codelineno-18-25"></a>
<a id="__codelineno-18-26" name="__codelineno-18-26" href="#__codelineno-18-26"></a><span class="w"> </span><span class="cm">/* 队尾入队操作 */</span>
<a id="__codelineno-18-27" name="__codelineno-18-27" href="#__codelineno-18-27"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-28" name="__codelineno-18-28" href="#__codelineno-18-28"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-18-29" name="__codelineno-18-29" href="#__codelineno-18-29"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-18-30" name="__codelineno-18-30" href="#__codelineno-18-30"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-31" name="__codelineno-18-31" href="#__codelineno-18-31"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-32" name="__codelineno-18-32" href="#__codelineno-18-32"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-33" name="__codelineno-18-33" href="#__codelineno-18-33"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-34" name="__codelineno-18-34" href="#__codelineno-18-34"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-18-35" name="__codelineno-18-35" href="#__codelineno-18-35"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-36" name="__codelineno-18-36" href="#__codelineno-18-36"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">;</span>
<a id="__codelineno-18-37" name="__codelineno-18-37" href="#__codelineno-18-37"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-18-38" name="__codelineno-18-38" href="#__codelineno-18-38"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-39" name="__codelineno-18-39" href="#__codelineno-18-39"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-18-40" name="__codelineno-18-40" href="#__codelineno-18-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-41" name="__codelineno-18-41" href="#__codelineno-18-41"></a>
<a id="__codelineno-18-42" name="__codelineno-18-42" href="#__codelineno-18-42"></a><span class="w"> </span><span class="cm">/* 队首入队操作 */</span>
<a id="__codelineno-18-43" name="__codelineno-18-43" href="#__codelineno-18-43"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-44" name="__codelineno-18-44" href="#__codelineno-18-44"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-18-45" name="__codelineno-18-45" href="#__codelineno-18-45"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-18-46" name="__codelineno-18-46" href="#__codelineno-18-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-47" name="__codelineno-18-47" href="#__codelineno-18-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-48" name="__codelineno-18-48" href="#__codelineno-18-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-49" name="__codelineno-18-49" href="#__codelineno-18-49"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-50" name="__codelineno-18-50" href="#__codelineno-18-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-18-51" name="__codelineno-18-51" href="#__codelineno-18-51"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-18-52" name="__codelineno-18-52" href="#__codelineno-18-52"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-18-53" name="__codelineno-18-53" href="#__codelineno-18-53"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-18-54" name="__codelineno-18-54" href="#__codelineno-18-54"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-55" name="__codelineno-18-55" href="#__codelineno-18-55"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-18-56" name="__codelineno-18-56" href="#__codelineno-18-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-57" name="__codelineno-18-57" href="#__codelineno-18-57"></a>
<a id="__codelineno-18-58" name="__codelineno-18-58" href="#__codelineno-18-58"></a><span class="w"> </span><span class="cm">/* 队尾出队操作 */</span>
<a id="__codelineno-18-59" name="__codelineno-18-59" href="#__codelineno-18-59"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-60" name="__codelineno-18-60" href="#__codelineno-18-60"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-61" name="__codelineno-18-61" href="#__codelineno-18-61"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-62" name="__codelineno-18-62" href="#__codelineno-18-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-63" name="__codelineno-18-63" href="#__codelineno-18-63"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-18-64" name="__codelineno-18-64" href="#__codelineno-18-64"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-18-65" name="__codelineno-18-65" href="#__codelineno-18-65"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="p">;</span>
<a id="__codelineno-18-66" name="__codelineno-18-66" href="#__codelineno-18-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-67" name="__codelineno-18-67" href="#__codelineno-18-67"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-68" name="__codelineno-18-68" href="#__codelineno-18-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-69" name="__codelineno-18-69" href="#__codelineno-18-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-70" name="__codelineno-18-70" href="#__codelineno-18-70"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-18-71" name="__codelineno-18-71" href="#__codelineno-18-71"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-18-72" name="__codelineno-18-72" href="#__codelineno-18-72"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-18-73" name="__codelineno-18-73" href="#__codelineno-18-73"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-74" name="__codelineno-18-74" href="#__codelineno-18-74"></a>
<a id="__codelineno-18-75" name="__codelineno-18-75" href="#__codelineno-18-75"></a><span class="w"> </span><span class="cm">/* 队首出队操作 */</span>
<a id="__codelineno-18-76" name="__codelineno-18-76" href="#__codelineno-18-76"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-77" name="__codelineno-18-77" href="#__codelineno-18-77"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-78" name="__codelineno-18-78" href="#__codelineno-18-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-79" name="__codelineno-18-79" href="#__codelineno-18-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-80" name="__codelineno-18-80" href="#__codelineno-18-80"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-18-81" name="__codelineno-18-81" href="#__codelineno-18-81"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-18-82" name="__codelineno-18-82" href="#__codelineno-18-82"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-18-83" name="__codelineno-18-83" href="#__codelineno-18-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-84" name="__codelineno-18-84" href="#__codelineno-18-84"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-85" name="__codelineno-18-85" href="#__codelineno-18-85"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-18-86" name="__codelineno-18-86" href="#__codelineno-18-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-87" name="__codelineno-18-87" href="#__codelineno-18-87"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-18-88" name="__codelineno-18-88" href="#__codelineno-18-88"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-18-89" name="__codelineno-18-89" href="#__codelineno-18-89"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-18-90" name="__codelineno-18-90" href="#__codelineno-18-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-91" name="__codelineno-18-91" href="#__codelineno-18-91"></a>
<a id="__codelineno-18-92" name="__codelineno-18-92" href="#__codelineno-18-92"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-18-93" name="__codelineno-18-93" href="#__codelineno-18-93"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-94" name="__codelineno-18-94" href="#__codelineno-18-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-18-95" name="__codelineno-18-95" href="#__codelineno-18-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-96" name="__codelineno-18-96" href="#__codelineno-18-96"></a>
<a id="__codelineno-18-97" name="__codelineno-18-97" href="#__codelineno-18-97"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-18-98" name="__codelineno-18-98" href="#__codelineno-18-98"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-99" name="__codelineno-18-99" href="#__codelineno-18-99"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-18-100" name="__codelineno-18-100" href="#__codelineno-18-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-101" name="__codelineno-18-101" href="#__codelineno-18-101"></a>
<a id="__codelineno-18-102" name="__codelineno-18-102" href="#__codelineno-18-102"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-18-103" name="__codelineno-18-103" href="#__codelineno-18-103"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-104" name="__codelineno-18-104" href="#__codelineno-18-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-18-105" name="__codelineno-18-105" href="#__codelineno-18-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-106" name="__codelineno-18-106" href="#__codelineno-18-106"></a>
<a id="__codelineno-18-107" name="__codelineno-18-107" href="#__codelineno-18-107"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-18-108" name="__codelineno-18-108" href="#__codelineno-18-108"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-109" name="__codelineno-18-109" href="#__codelineno-18-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-18-110" name="__codelineno-18-110" href="#__codelineno-18-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-111" name="__codelineno-18-111" href="#__codelineno-18-111"></a>
<a id="__codelineno-18-112" name="__codelineno-18-112" href="#__codelineno-18-112"></a><span class="w"> </span><span class="cm">/* 打印双向队列 */</span>
<a id="__codelineno-18-113" name="__codelineno-18-113" href="#__codelineno-18-113"></a><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-114" name="__codelineno-18-114" href="#__codelineno-18-114"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">arr</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-18-115" name="__codelineno-18-115" href="#__codelineno-18-115"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-18-116" name="__codelineno-18-116" href="#__codelineno-18-116"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-18-117" name="__codelineno-18-117" href="#__codelineno-18-117"></a><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">temp</span><span class="p">.</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-18-118" name="__codelineno-18-118" href="#__codelineno-18-118"></a><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-18-119" name="__codelineno-18-119" href="#__codelineno-18-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-120" name="__codelineno-18-120" href="#__codelineno-18-120"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;[&#39;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s1">&#39;]&#39;</span><span class="p">);</span>
<a id="__codelineno-18-121" name="__codelineno-18-121" href="#__codelineno-18-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-18-122" name="__codelineno-18-122" href="#__codelineno-18-122"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.ts</span><pre><span></span><code><a id="__codelineno-19-1" name="__codelineno-19-1" href="#__codelineno-19-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-19-2" name="__codelineno-19-2" href="#__codelineno-19-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-3" name="__codelineno-19-3" href="#__codelineno-19-3"></a><span class="w"> </span><span class="nx">prev</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用 (指针)</span>
<a id="__codelineno-19-4" name="__codelineno-19-4" href="#__codelineno-19-4"></a><span class="w"> </span><span class="nx">next</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用 (指针)</span>
<a id="__codelineno-19-5" name="__codelineno-19-5" href="#__codelineno-19-5"></a><span class="w"> </span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-19-6" name="__codelineno-19-6" href="#__codelineno-19-6"></a>
<a id="__codelineno-19-7" name="__codelineno-19-7" href="#__codelineno-19-7"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-8" name="__codelineno-19-8" href="#__codelineno-19-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-19-9" name="__codelineno-19-9" href="#__codelineno-19-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-10" name="__codelineno-19-10" href="#__codelineno-19-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-11" name="__codelineno-19-11" href="#__codelineno-19-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-12" name="__codelineno-19-12" href="#__codelineno-19-12"></a><span class="p">}</span>
<a id="__codelineno-19-13" name="__codelineno-19-13" href="#__codelineno-19-13"></a>
<a id="__codelineno-19-14" name="__codelineno-19-14" href="#__codelineno-19-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-19-15" name="__codelineno-19-15" href="#__codelineno-19-15"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-16" name="__codelineno-19-16" href="#__codelineno-19-16"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">front</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-19-17" name="__codelineno-19-17" href="#__codelineno-19-17"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">rear</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-19-18" name="__codelineno-19-18" href="#__codelineno-19-18"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">queSize</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-19-19" name="__codelineno-19-19" href="#__codelineno-19-19"></a>
<a id="__codelineno-19-20" name="__codelineno-19-20" href="#__codelineno-19-20"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-21" name="__codelineno-19-21" href="#__codelineno-19-21"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-22" name="__codelineno-19-22" href="#__codelineno-19-22"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-23" name="__codelineno-19-23" href="#__codelineno-19-23"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-19-24" name="__codelineno-19-24" href="#__codelineno-19-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-25" name="__codelineno-19-25" href="#__codelineno-19-25"></a>
<a id="__codelineno-19-26" name="__codelineno-19-26" href="#__codelineno-19-26"></a><span class="w"> </span><span class="cm">/* 队尾入队操作 */</span>
<a id="__codelineno-19-27" name="__codelineno-19-27" href="#__codelineno-19-27"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-28" name="__codelineno-19-28" href="#__codelineno-19-28"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-19-29" name="__codelineno-19-29" href="#__codelineno-19-29"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-19-30" name="__codelineno-19-30" href="#__codelineno-19-30"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-31" name="__codelineno-19-31" href="#__codelineno-19-31"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-32" name="__codelineno-19-32" href="#__codelineno-19-32"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-33" name="__codelineno-19-33" href="#__codelineno-19-33"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-34" name="__codelineno-19-34" href="#__codelineno-19-34"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-19-35" name="__codelineno-19-35" href="#__codelineno-19-35"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-36" name="__codelineno-19-36" href="#__codelineno-19-36"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">;</span>
<a id="__codelineno-19-37" name="__codelineno-19-37" href="#__codelineno-19-37"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-19-38" name="__codelineno-19-38" href="#__codelineno-19-38"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-39" name="__codelineno-19-39" href="#__codelineno-19-39"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-19-40" name="__codelineno-19-40" href="#__codelineno-19-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-41" name="__codelineno-19-41" href="#__codelineno-19-41"></a>
<a id="__codelineno-19-42" name="__codelineno-19-42" href="#__codelineno-19-42"></a><span class="w"> </span><span class="cm">/* 队首入队操作 */</span>
<a id="__codelineno-19-43" name="__codelineno-19-43" href="#__codelineno-19-43"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-44" name="__codelineno-19-44" href="#__codelineno-19-44"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-19-45" name="__codelineno-19-45" href="#__codelineno-19-45"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-19-46" name="__codelineno-19-46" href="#__codelineno-19-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-47" name="__codelineno-19-47" href="#__codelineno-19-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-48" name="__codelineno-19-48" href="#__codelineno-19-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-49" name="__codelineno-19-49" href="#__codelineno-19-49"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-50" name="__codelineno-19-50" href="#__codelineno-19-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-19-51" name="__codelineno-19-51" href="#__codelineno-19-51"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-19-52" name="__codelineno-19-52" href="#__codelineno-19-52"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-19-53" name="__codelineno-19-53" href="#__codelineno-19-53"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-19-54" name="__codelineno-19-54" href="#__codelineno-19-54"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-55" name="__codelineno-19-55" href="#__codelineno-19-55"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-19-56" name="__codelineno-19-56" href="#__codelineno-19-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-57" name="__codelineno-19-57" href="#__codelineno-19-57"></a>
<a id="__codelineno-19-58" name="__codelineno-19-58" href="#__codelineno-19-58"></a><span class="w"> </span><span class="cm">/* 队尾出队操作 */</span>
<a id="__codelineno-19-59" name="__codelineno-19-59" href="#__codelineno-19-59"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-60" name="__codelineno-19-60" href="#__codelineno-19-60"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-61" name="__codelineno-19-61" href="#__codelineno-19-61"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-62" name="__codelineno-19-62" href="#__codelineno-19-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-63" name="__codelineno-19-63" href="#__codelineno-19-63"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-19-64" name="__codelineno-19-64" href="#__codelineno-19-64"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-19-65" name="__codelineno-19-65" href="#__codelineno-19-65"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="p">;</span>
<a id="__codelineno-19-66" name="__codelineno-19-66" href="#__codelineno-19-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-67" name="__codelineno-19-67" href="#__codelineno-19-67"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-68" name="__codelineno-19-68" href="#__codelineno-19-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-69" name="__codelineno-19-69" href="#__codelineno-19-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-70" name="__codelineno-19-70" href="#__codelineno-19-70"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-19-71" name="__codelineno-19-71" href="#__codelineno-19-71"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-19-72" name="__codelineno-19-72" href="#__codelineno-19-72"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-19-73" name="__codelineno-19-73" href="#__codelineno-19-73"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-74" name="__codelineno-19-74" href="#__codelineno-19-74"></a>
<a id="__codelineno-19-75" name="__codelineno-19-75" href="#__codelineno-19-75"></a><span class="w"> </span><span class="cm">/* 队首出队操作 */</span>
<a id="__codelineno-19-76" name="__codelineno-19-76" href="#__codelineno-19-76"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-77" name="__codelineno-19-77" href="#__codelineno-19-77"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-78" name="__codelineno-19-78" href="#__codelineno-19-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-79" name="__codelineno-19-79" href="#__codelineno-19-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-80" name="__codelineno-19-80" href="#__codelineno-19-80"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-19-81" name="__codelineno-19-81" href="#__codelineno-19-81"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-19-82" name="__codelineno-19-82" href="#__codelineno-19-82"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-19-83" name="__codelineno-19-83" href="#__codelineno-19-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-84" name="__codelineno-19-84" href="#__codelineno-19-84"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-85" name="__codelineno-19-85" href="#__codelineno-19-85"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-86" name="__codelineno-19-86" href="#__codelineno-19-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-87" name="__codelineno-19-87" href="#__codelineno-19-87"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-19-88" name="__codelineno-19-88" href="#__codelineno-19-88"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-19-89" name="__codelineno-19-89" href="#__codelineno-19-89"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-19-90" name="__codelineno-19-90" href="#__codelineno-19-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-91" name="__codelineno-19-91" href="#__codelineno-19-91"></a>
<a id="__codelineno-19-92" name="__codelineno-19-92" href="#__codelineno-19-92"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-19-93" name="__codelineno-19-93" href="#__codelineno-19-93"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-94" name="__codelineno-19-94" href="#__codelineno-19-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="kt">this.rear.val</span><span class="p">;</span>
<a id="__codelineno-19-95" name="__codelineno-19-95" href="#__codelineno-19-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-96" name="__codelineno-19-96" href="#__codelineno-19-96"></a>
<a id="__codelineno-19-97" name="__codelineno-19-97" href="#__codelineno-19-97"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-19-98" name="__codelineno-19-98" href="#__codelineno-19-98"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-99" name="__codelineno-19-99" href="#__codelineno-19-99"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="kt">this.front.val</span><span class="p">;</span>
<a id="__codelineno-19-100" name="__codelineno-19-100" href="#__codelineno-19-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-101" name="__codelineno-19-101" href="#__codelineno-19-101"></a>
<a id="__codelineno-19-102" name="__codelineno-19-102" href="#__codelineno-19-102"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-19-103" name="__codelineno-19-103" href="#__codelineno-19-103"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-104" name="__codelineno-19-104" href="#__codelineno-19-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-19-105" name="__codelineno-19-105" href="#__codelineno-19-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-106" name="__codelineno-19-106" href="#__codelineno-19-106"></a>
<a id="__codelineno-19-107" name="__codelineno-19-107" href="#__codelineno-19-107"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-19-108" name="__codelineno-19-108" href="#__codelineno-19-108"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-109" name="__codelineno-19-109" href="#__codelineno-19-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-19-110" name="__codelineno-19-110" href="#__codelineno-19-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-111" name="__codelineno-19-111" href="#__codelineno-19-111"></a>
<a id="__codelineno-19-112" name="__codelineno-19-112" href="#__codelineno-19-112"></a><span class="w"> </span><span class="cm">/* 打印双向队列 */</span>
<a id="__codelineno-19-113" name="__codelineno-19-113" href="#__codelineno-19-113"></a><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-114" name="__codelineno-19-114" href="#__codelineno-19-114"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">arr</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-19-115" name="__codelineno-19-115" href="#__codelineno-19-115"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-19-116" name="__codelineno-19-116" href="#__codelineno-19-116"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-117" name="__codelineno-19-117" href="#__codelineno-19-117"></a><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">temp</span><span class="p">.</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-19-118" name="__codelineno-19-118" href="#__codelineno-19-118"></a><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-19-119" name="__codelineno-19-119" href="#__codelineno-19-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-120" name="__codelineno-19-120" href="#__codelineno-19-120"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;[&#39;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s1">&#39;]&#39;</span><span class="p">);</span>
<a id="__codelineno-19-121" name="__codelineno-19-121" href="#__codelineno-19-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-122" name="__codelineno-19-122" href="#__codelineno-19-122"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.dart</span><pre><span></span><code><a id="__codelineno-20-1" name="__codelineno-20-1" href="#__codelineno-20-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-20-2" name="__codelineno-20-2" href="#__codelineno-20-2"></a><span class="kd">class</span><span class="w"> </span><span class="nc">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-3" name="__codelineno-20-3" href="#__codelineno-20-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-20-4" name="__codelineno-20-4" href="#__codelineno-20-4"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用</span>
<a id="__codelineno-20-5" name="__codelineno-20-5" href="#__codelineno-20-5"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用</span>
<a id="__codelineno-20-6" name="__codelineno-20-6" href="#__codelineno-20-6"></a>
<a id="__codelineno-20-7" name="__codelineno-20-7" href="#__codelineno-20-7"></a><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="n">val</span><span class="p">,</span><span class="w"> </span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="n">next</span><span class="p">,</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">prev</span><span class="p">});</span>
<a id="__codelineno-20-8" name="__codelineno-20-8" href="#__codelineno-20-8"></a><span class="p">}</span>
<a id="__codelineno-20-9" name="__codelineno-20-9" href="#__codelineno-20-9"></a>
<a id="__codelineno-20-10" name="__codelineno-20-10" href="#__codelineno-20-10"></a><span class="cm">/* 基于双向链表实现的双向对列 */</span>
<a id="__codelineno-20-11" name="__codelineno-20-11" href="#__codelineno-20-11"></a><span class="kd">class</span><span class="w"> </span><span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-12" name="__codelineno-20-12" href="#__codelineno-20-12"></a><span class="w"> </span><span class="kd">late</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">_front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 _front</span>
<a id="__codelineno-20-13" name="__codelineno-20-13" href="#__codelineno-20-13"></a><span class="w"> </span><span class="kd">late</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">_rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾节点 _rear</span>
<a id="__codelineno-20-14" name="__codelineno-20-14" href="#__codelineno-20-14"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">_queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-20-15" name="__codelineno-20-15" href="#__codelineno-20-15"></a>
<a id="__codelineno-20-16" name="__codelineno-20-16" href="#__codelineno-20-16"></a><span class="w"> </span><span class="n">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-17" name="__codelineno-20-17" href="#__codelineno-20-17"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-18" name="__codelineno-20-18" href="#__codelineno-20-18"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-19" name="__codelineno-20-19" href="#__codelineno-20-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-20" name="__codelineno-20-20" href="#__codelineno-20-20"></a>
<a id="__codelineno-20-21" name="__codelineno-20-21" href="#__codelineno-20-21"></a><span class="w"> </span><span class="cm">/* 获取双向队列长度 */</span>
<a id="__codelineno-20-22" name="__codelineno-20-22" href="#__codelineno-20-22"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-23" name="__codelineno-20-23" href="#__codelineno-20-23"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_queSize</span><span class="p">;</span>
<a id="__codelineno-20-24" name="__codelineno-20-24" href="#__codelineno-20-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-25" name="__codelineno-20-25" href="#__codelineno-20-25"></a>
<a id="__codelineno-20-26" name="__codelineno-20-26" href="#__codelineno-20-26"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-20-27" name="__codelineno-20-27" href="#__codelineno-20-27"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-28" name="__codelineno-20-28" href="#__codelineno-20-28"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-20-29" name="__codelineno-20-29" href="#__codelineno-20-29"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-30" name="__codelineno-20-30" href="#__codelineno-20-30"></a>
<a id="__codelineno-20-31" name="__codelineno-20-31" href="#__codelineno-20-31"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-20-32" name="__codelineno-20-32" href="#__codelineno-20-32"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-33" name="__codelineno-20-33" href="#__codelineno-20-33"></a><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="kt">num</span><span class="p">);</span>
<a id="__codelineno-20-34" name="__codelineno-20-34" href="#__codelineno-20-34"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-35" name="__codelineno-20-35" href="#__codelineno-20-35"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 _front 和 _rear 都指向 node</span>
<a id="__codelineno-20-36" name="__codelineno-20-36" href="#__codelineno-20-36"></a><span class="w"> </span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-20-37" name="__codelineno-20-37" href="#__codelineno-20-37"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-38" name="__codelineno-20-38" href="#__codelineno-20-38"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-20-39" name="__codelineno-20-39" href="#__codelineno-20-39"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-20-40" name="__codelineno-20-40" href="#__codelineno-20-40"></a><span class="w"> </span><span class="n">_front</span><span class="o">!</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-20-41" name="__codelineno-20-41" href="#__codelineno-20-41"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_front</span><span class="p">;</span>
<a id="__codelineno-20-42" name="__codelineno-20-42" href="#__codelineno-20-42"></a><span class="w"> </span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-20-43" name="__codelineno-20-43" href="#__codelineno-20-43"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-44" name="__codelineno-20-44" href="#__codelineno-20-44"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-20-45" name="__codelineno-20-45" href="#__codelineno-20-45"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-20-46" name="__codelineno-20-46" href="#__codelineno-20-46"></a><span class="w"> </span><span class="n">_rear</span><span class="o">!</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-20-47" name="__codelineno-20-47" href="#__codelineno-20-47"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_rear</span><span class="p">;</span>
<a id="__codelineno-20-48" name="__codelineno-20-48" href="#__codelineno-20-48"></a><span class="w"> </span><span class="n">_rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-20-49" name="__codelineno-20-49" href="#__codelineno-20-49"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-50" name="__codelineno-20-50" href="#__codelineno-20-50"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-20-51" name="__codelineno-20-51" href="#__codelineno-20-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-52" name="__codelineno-20-52" href="#__codelineno-20-52"></a>
<a id="__codelineno-20-53" name="__codelineno-20-53" href="#__codelineno-20-53"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-20-54" name="__codelineno-20-54" href="#__codelineno-20-54"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-55" name="__codelineno-20-55" href="#__codelineno-20-55"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="kt">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-20-56" name="__codelineno-20-56" href="#__codelineno-20-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-57" name="__codelineno-20-57" href="#__codelineno-20-57"></a>
<a id="__codelineno-20-58" name="__codelineno-20-58" href="#__codelineno-20-58"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-20-59" name="__codelineno-20-59" href="#__codelineno-20-59"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-60" name="__codelineno-20-60" href="#__codelineno-20-60"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="kt">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-20-61" name="__codelineno-20-61" href="#__codelineno-20-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-62" name="__codelineno-20-62" href="#__codelineno-20-62"></a>
<a id="__codelineno-20-63" name="__codelineno-20-63" href="#__codelineno-20-63"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-20-64" name="__codelineno-20-64" href="#__codelineno-20-64"></a><span class="w"> </span><span class="kt">int</span><span class="o">?</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-65" name="__codelineno-20-65" href="#__codelineno-20-65"></a><span class="w"> </span><span class="c1">// 若队列为空,直接返回 null</span>
<a id="__codelineno-20-66" name="__codelineno-20-66" href="#__codelineno-20-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-67" name="__codelineno-20-67" href="#__codelineno-20-67"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-68" name="__codelineno-20-68" href="#__codelineno-20-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-69" name="__codelineno-20-69" href="#__codelineno-20-69"></a><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-20-70" name="__codelineno-20-70" href="#__codelineno-20-70"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-71" name="__codelineno-20-71" href="#__codelineno-20-71"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-20-72" name="__codelineno-20-72" href="#__codelineno-20-72"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_front</span><span class="o">!</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-20-73" name="__codelineno-20-73" href="#__codelineno-20-73"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-20-74" name="__codelineno-20-74" href="#__codelineno-20-74"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_front</span><span class="o">!</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-20-75" name="__codelineno-20-75" href="#__codelineno-20-75"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-76" name="__codelineno-20-76" href="#__codelineno-20-76"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-77" name="__codelineno-20-77" href="#__codelineno-20-77"></a><span class="w"> </span><span class="n">_front</span><span class="o">!</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-78" name="__codelineno-20-78" href="#__codelineno-20-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-79" name="__codelineno-20-79" href="#__codelineno-20-79"></a><span class="w"> </span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-20-80" name="__codelineno-20-80" href="#__codelineno-20-80"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-81" name="__codelineno-20-81" href="#__codelineno-20-81"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-20-82" name="__codelineno-20-82" href="#__codelineno-20-82"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_rear</span><span class="o">!</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-20-83" name="__codelineno-20-83" href="#__codelineno-20-83"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-20-84" name="__codelineno-20-84" href="#__codelineno-20-84"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_rear</span><span class="o">!</span><span class="p">.</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-20-85" name="__codelineno-20-85" href="#__codelineno-20-85"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-86" name="__codelineno-20-86" href="#__codelineno-20-86"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-87" name="__codelineno-20-87" href="#__codelineno-20-87"></a><span class="w"> </span><span class="n">_rear</span><span class="o">!</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-20-88" name="__codelineno-20-88" href="#__codelineno-20-88"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-89" name="__codelineno-20-89" href="#__codelineno-20-89"></a><span class="w"> </span><span class="n">_rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-20-90" name="__codelineno-20-90" href="#__codelineno-20-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-91" name="__codelineno-20-91" href="#__codelineno-20-91"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-20-92" name="__codelineno-20-92" href="#__codelineno-20-92"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-20-93" name="__codelineno-20-93" href="#__codelineno-20-93"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-94" name="__codelineno-20-94" href="#__codelineno-20-94"></a>
<a id="__codelineno-20-95" name="__codelineno-20-95" href="#__codelineno-20-95"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-20-96" name="__codelineno-20-96" href="#__codelineno-20-96"></a><span class="w"> </span><span class="kt">int</span><span class="o">?</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-97" name="__codelineno-20-97" href="#__codelineno-20-97"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-20-98" name="__codelineno-20-98" href="#__codelineno-20-98"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-99" name="__codelineno-20-99" href="#__codelineno-20-99"></a>
<a id="__codelineno-20-100" name="__codelineno-20-100" href="#__codelineno-20-100"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-20-101" name="__codelineno-20-101" href="#__codelineno-20-101"></a><span class="w"> </span><span class="kt">int</span><span class="o">?</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-102" name="__codelineno-20-102" href="#__codelineno-20-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-20-103" name="__codelineno-20-103" href="#__codelineno-20-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-104" name="__codelineno-20-104" href="#__codelineno-20-104"></a>
<a id="__codelineno-20-105" name="__codelineno-20-105" href="#__codelineno-20-105"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-20-106" name="__codelineno-20-106" href="#__codelineno-20-106"></a><span class="w"> </span><span class="kt">int</span><span class="o">?</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-107" name="__codelineno-20-107" href="#__codelineno-20-107"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_front</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-20-108" name="__codelineno-20-108" href="#__codelineno-20-108"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-109" name="__codelineno-20-109" href="#__codelineno-20-109"></a>
<a id="__codelineno-20-110" name="__codelineno-20-110" href="#__codelineno-20-110"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-20-111" name="__codelineno-20-111" href="#__codelineno-20-111"></a><span class="w"> </span><span class="kt">int</span><span class="o">?</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-112" name="__codelineno-20-112" href="#__codelineno-20-112"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_rear</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-20-113" name="__codelineno-20-113" href="#__codelineno-20-113"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-114" name="__codelineno-20-114" href="#__codelineno-20-114"></a>
<a id="__codelineno-20-115" name="__codelineno-20-115" href="#__codelineno-20-115"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-20-116" name="__codelineno-20-116" href="#__codelineno-20-116"></a><span class="w"> </span><span class="n">List</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-117" name="__codelineno-20-117" href="#__codelineno-20-117"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_front</span><span class="p">;</span>
<a id="__codelineno-20-118" name="__codelineno-20-118" href="#__codelineno-20-118"></a><span class="w"> </span><span class="kd">final</span><span class="w"> </span><span class="n">List</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-20-119" name="__codelineno-20-119" href="#__codelineno-20-119"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">_queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-120" name="__codelineno-20-120" href="#__codelineno-20-120"></a><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">add</span><span class="p">(</span><span class="n">node</span><span class="o">!</span><span class="p">.</span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-20-121" name="__codelineno-20-121" href="#__codelineno-20-121"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-20-122" name="__codelineno-20-122" href="#__codelineno-20-122"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-123" name="__codelineno-20-123" href="#__codelineno-20-123"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-20-124" name="__codelineno-20-124" href="#__codelineno-20-124"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-125" name="__codelineno-20-125" href="#__codelineno-20-125"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.rs</span><pre><span></span><code><a id="__codelineno-21-1" name="__codelineno-21-1" href="#__codelineno-21-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-21-2" name="__codelineno-21-2" href="#__codelineno-21-2"></a><span class="k">pub</span><span class="w"> </span><span class="k">struct</span> <span class="nc">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-3" name="__codelineno-21-3" href="#__codelineno-21-3"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="n">val</span>: <span class="nc">T</span><span class="p">,</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-21-4" name="__codelineno-21-4" href="#__codelineno-21-4"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="n">next</span>: <span class="nb">Option</span><span class="o">&lt;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="p">,</span><span class="w"> </span><span class="c1">// 后继节点指针</span>
<a id="__codelineno-21-5" name="__codelineno-21-5" href="#__codelineno-21-5"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="n">prev</span>: <span class="nb">Option</span><span class="o">&lt;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="p">,</span><span class="w"> </span><span class="c1">// 前驱节点指针</span>
<a id="__codelineno-21-6" name="__codelineno-21-6" href="#__codelineno-21-6"></a><span class="p">}</span>
<a id="__codelineno-21-7" name="__codelineno-21-7" href="#__codelineno-21-7"></a>
<a id="__codelineno-21-8" name="__codelineno-21-8" href="#__codelineno-21-8"></a><span class="k">impl</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-9" name="__codelineno-21-9" href="#__codelineno-21-9"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">new</span><span class="p">(</span><span class="n">val</span>: <span class="nc">T</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nc">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-10" name="__codelineno-21-10" href="#__codelineno-21-10"></a><span class="w"> </span><span class="n">Rc</span>::<span class="n">new</span><span class="p">(</span><span class="n">RefCell</span>::<span class="n">new</span><span class="p">(</span><span class="n">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-11" name="__codelineno-21-11" href="#__codelineno-21-11"></a><span class="w"> </span><span class="n">val</span><span class="p">,</span>
<a id="__codelineno-21-12" name="__codelineno-21-12" href="#__codelineno-21-12"></a><span class="w"> </span><span class="n">next</span>: <span class="nb">None</span><span class="p">,</span>
<a id="__codelineno-21-13" name="__codelineno-21-13" href="#__codelineno-21-13"></a><span class="w"> </span><span class="n">prev</span>: <span class="nb">None</span><span class="p">,</span>
<a id="__codelineno-21-14" name="__codelineno-21-14" href="#__codelineno-21-14"></a><span class="w"> </span><span class="p">}))</span>
<a id="__codelineno-21-15" name="__codelineno-21-15" href="#__codelineno-21-15"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-16" name="__codelineno-21-16" href="#__codelineno-21-16"></a><span class="p">}</span>
<a id="__codelineno-21-17" name="__codelineno-21-17" href="#__codelineno-21-17"></a>
<a id="__codelineno-21-18" name="__codelineno-21-18" href="#__codelineno-21-18"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-21-19" name="__codelineno-21-19" href="#__codelineno-21-19"></a><span class="cp">#[allow(dead_code)]</span>
<a id="__codelineno-21-20" name="__codelineno-21-20" href="#__codelineno-21-20"></a><span class="k">pub</span><span class="w"> </span><span class="k">struct</span> <span class="nc">LinkedListDeque</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-21" name="__codelineno-21-21" href="#__codelineno-21-21"></a><span class="w"> </span><span class="n">front</span>: <span class="nb">Option</span><span class="o">&lt;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="p">,</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-21-22" name="__codelineno-21-22" href="#__codelineno-21-22"></a><span class="w"> </span><span class="n">rear</span>: <span class="nb">Option</span><span class="o">&lt;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="p">,</span><span class="w"> </span><span class="c1">// 尾节点 rear </span>
<a id="__codelineno-21-23" name="__codelineno-21-23" href="#__codelineno-21-23"></a><span class="w"> </span><span class="n">que_size</span>: <span class="kt">usize</span><span class="p">,</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-21-24" name="__codelineno-21-24" href="#__codelineno-21-24"></a><span class="p">}</span>
<a id="__codelineno-21-25" name="__codelineno-21-25" href="#__codelineno-21-25"></a>
<a id="__codelineno-21-26" name="__codelineno-21-26" href="#__codelineno-21-26"></a><span class="k">impl</span><span class="o">&lt;</span><span class="n">T</span>: <span class="nb">Copy</span><span class="o">&gt;</span><span class="w"> </span><span class="n">LinkedListDeque</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-27" name="__codelineno-21-27" href="#__codelineno-21-27"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">new</span><span class="p">()</span><span class="w"> </span>-&gt; <span class="nc">Self</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-28" name="__codelineno-21-28" href="#__codelineno-21-28"></a><span class="w"> </span><span class="bp">Self</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-29" name="__codelineno-21-29" href="#__codelineno-21-29"></a><span class="w"> </span><span class="n">front</span>: <span class="nb">None</span><span class="p">,</span>
<a id="__codelineno-21-30" name="__codelineno-21-30" href="#__codelineno-21-30"></a><span class="w"> </span><span class="n">rear</span>: <span class="nb">None</span><span class="p">,</span>
<a id="__codelineno-21-31" name="__codelineno-21-31" href="#__codelineno-21-31"></a><span class="w"> </span><span class="n">que_size</span>: <span class="mi">0</span><span class="p">,</span><span class="w"> </span>
<a id="__codelineno-21-32" name="__codelineno-21-32" href="#__codelineno-21-32"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-33" name="__codelineno-21-33" href="#__codelineno-21-33"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-34" name="__codelineno-21-34" href="#__codelineno-21-34"></a>
<a id="__codelineno-21-35" name="__codelineno-21-35" href="#__codelineno-21-35"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-21-36" name="__codelineno-21-36" href="#__codelineno-21-36"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">size</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">usize</span> <span class="p">{</span>
<a id="__codelineno-21-37" name="__codelineno-21-37" href="#__codelineno-21-37"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="p">;</span>
<a id="__codelineno-21-38" name="__codelineno-21-38" href="#__codelineno-21-38"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-39" name="__codelineno-21-39" href="#__codelineno-21-39"></a>
<a id="__codelineno-21-40" name="__codelineno-21-40" href="#__codelineno-21-40"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-21-41" name="__codelineno-21-41" href="#__codelineno-21-41"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">is_empty</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">bool</span> <span class="p">{</span>
<a id="__codelineno-21-42" name="__codelineno-21-42" href="#__codelineno-21-42"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-21-43" name="__codelineno-21-43" href="#__codelineno-21-43"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-44" name="__codelineno-21-44" href="#__codelineno-21-44"></a>
<a id="__codelineno-21-45" name="__codelineno-21-45" href="#__codelineno-21-45"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-21-46" name="__codelineno-21-46" href="#__codelineno-21-46"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">push</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span>: <span class="nc">T</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span>: <span class="kt">bool</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-47" name="__codelineno-21-47" href="#__codelineno-21-47"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">ListNode</span>::<span class="n">new</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-21-48" name="__codelineno-21-48" href="#__codelineno-21-48"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-21-49" name="__codelineno-21-49" href="#__codelineno-21-49"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">is_front</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-50" name="__codelineno-21-50" href="#__codelineno-21-50"></a><span class="w"> </span><span class="k">match</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="n">take</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-51" name="__codelineno-21-51" href="#__codelineno-21-51"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-21-52" name="__codelineno-21-52" href="#__codelineno-21-52"></a><span class="w"> </span><span class="nb">None</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-53" name="__codelineno-21-53" href="#__codelineno-21-53"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">.</span><span class="n">clone</span><span class="p">());</span>
<a id="__codelineno-21-54" name="__codelineno-21-54" href="#__codelineno-21-54"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-21-55" name="__codelineno-21-55" href="#__codelineno-21-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-56" name="__codelineno-21-56" href="#__codelineno-21-56"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-21-57" name="__codelineno-21-57" href="#__codelineno-21-57"></a><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">old_front</span><span class="p">)</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-58" name="__codelineno-21-58" href="#__codelineno-21-58"></a><span class="w"> </span><span class="n">old_front</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">.</span><span class="n">clone</span><span class="p">());</span>
<a id="__codelineno-21-59" name="__codelineno-21-59" href="#__codelineno-21-59"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">old_front</span><span class="p">);</span>
<a id="__codelineno-21-60" name="__codelineno-21-60" href="#__codelineno-21-60"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">);</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-21-61" name="__codelineno-21-61" href="#__codelineno-21-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-62" name="__codelineno-21-62" href="#__codelineno-21-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-63" name="__codelineno-21-63" href="#__codelineno-21-63"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-21-64" name="__codelineno-21-64" href="#__codelineno-21-64"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-21-65" name="__codelineno-21-65" href="#__codelineno-21-65"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-66" name="__codelineno-21-66" href="#__codelineno-21-66"></a><span class="w"> </span><span class="k">match</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="n">take</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-67" name="__codelineno-21-67" href="#__codelineno-21-67"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-21-68" name="__codelineno-21-68" href="#__codelineno-21-68"></a><span class="w"> </span><span class="nb">None</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-69" name="__codelineno-21-69" href="#__codelineno-21-69"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">.</span><span class="n">clone</span><span class="p">());</span>
<a id="__codelineno-21-70" name="__codelineno-21-70" href="#__codelineno-21-70"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-21-71" name="__codelineno-21-71" href="#__codelineno-21-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-72" name="__codelineno-21-72" href="#__codelineno-21-72"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-21-73" name="__codelineno-21-73" href="#__codelineno-21-73"></a><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">old_rear</span><span class="p">)</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-74" name="__codelineno-21-74" href="#__codelineno-21-74"></a><span class="w"> </span><span class="n">old_rear</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">.</span><span class="n">clone</span><span class="p">());</span>
<a id="__codelineno-21-75" name="__codelineno-21-75" href="#__codelineno-21-75"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">old_rear</span><span class="p">);</span>
<a id="__codelineno-21-76" name="__codelineno-21-76" href="#__codelineno-21-76"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">);</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-21-77" name="__codelineno-21-77" href="#__codelineno-21-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-78" name="__codelineno-21-78" href="#__codelineno-21-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-79" name="__codelineno-21-79" href="#__codelineno-21-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-80" name="__codelineno-21-80" href="#__codelineno-21-80"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-21-81" name="__codelineno-21-81" href="#__codelineno-21-81"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-82" name="__codelineno-21-82" href="#__codelineno-21-82"></a>
<a id="__codelineno-21-83" name="__codelineno-21-83" href="#__codelineno-21-83"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-21-84" name="__codelineno-21-84" href="#__codelineno-21-84"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">push_first</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span>: <span class="nc">T</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-85" name="__codelineno-21-85" href="#__codelineno-21-85"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-21-86" name="__codelineno-21-86" href="#__codelineno-21-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-87" name="__codelineno-21-87" href="#__codelineno-21-87"></a>
<a id="__codelineno-21-88" name="__codelineno-21-88" href="#__codelineno-21-88"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-21-89" name="__codelineno-21-89" href="#__codelineno-21-89"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">push_last</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span>: <span class="nc">T</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-90" name="__codelineno-21-90" href="#__codelineno-21-90"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-21-91" name="__codelineno-21-91" href="#__codelineno-21-91"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-92" name="__codelineno-21-92" href="#__codelineno-21-92"></a>
<a id="__codelineno-21-93" name="__codelineno-21-93" href="#__codelineno-21-93"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-21-94" name="__codelineno-21-94" href="#__codelineno-21-94"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">pop</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span>: <span class="kt">bool</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Option</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-95" name="__codelineno-21-95" href="#__codelineno-21-95"></a><span class="w"> </span><span class="c1">// 若队列为空,直接返回 None</span>
<a id="__codelineno-21-96" name="__codelineno-21-96" href="#__codelineno-21-96"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">is_empty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span>
<a id="__codelineno-21-97" name="__codelineno-21-97" href="#__codelineno-21-97"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nb">None</span><span class="w"> </span>
<a id="__codelineno-21-98" name="__codelineno-21-98" href="#__codelineno-21-98"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-21-99" name="__codelineno-21-99" href="#__codelineno-21-99"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-21-100" name="__codelineno-21-100" href="#__codelineno-21-100"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="n">is_front</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-101" name="__codelineno-21-101" href="#__codelineno-21-101"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="n">take</span><span class="p">().</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="n">old_front</span><span class="o">|</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-102" name="__codelineno-21-102" href="#__codelineno-21-102"></a><span class="w"> </span><span class="k">match</span><span class="w"> </span><span class="n">old_front</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">next</span><span class="p">.</span><span class="n">take</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-103" name="__codelineno-21-103" href="#__codelineno-21-103"></a><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">new_front</span><span class="p">)</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-104" name="__codelineno-21-104" href="#__codelineno-21-104"></a><span class="w"> </span><span class="n">new_front</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">prev</span><span class="p">.</span><span class="n">take</span><span class="p">();</span>
<a id="__codelineno-21-105" name="__codelineno-21-105" href="#__codelineno-21-105"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">new_front</span><span class="p">);</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-21-106" name="__codelineno-21-106" href="#__codelineno-21-106"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-107" name="__codelineno-21-107" href="#__codelineno-21-107"></a><span class="w"> </span><span class="nb">None</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-108" name="__codelineno-21-108" href="#__codelineno-21-108"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="n">take</span><span class="p">();</span>
<a id="__codelineno-21-109" name="__codelineno-21-109" href="#__codelineno-21-109"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-110" name="__codelineno-21-110" href="#__codelineno-21-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-111" name="__codelineno-21-111" href="#__codelineno-21-111"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-21-112" name="__codelineno-21-112" href="#__codelineno-21-112"></a><span class="w"> </span><span class="n">Rc</span>::<span class="n">try_unwrap</span><span class="p">(</span><span class="n">old_front</span><span class="p">).</span><span class="n">ok</span><span class="p">().</span><span class="n">unwrap</span><span class="p">().</span><span class="n">into_inner</span><span class="p">().</span><span class="n">val</span>
<a id="__codelineno-21-113" name="__codelineno-21-113" href="#__codelineno-21-113"></a><span class="w"> </span><span class="p">})</span>
<a id="__codelineno-21-114" name="__codelineno-21-114" href="#__codelineno-21-114"></a>
<a id="__codelineno-21-115" name="__codelineno-21-115" href="#__codelineno-21-115"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-21-116" name="__codelineno-21-116" href="#__codelineno-21-116"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-21-117" name="__codelineno-21-117" href="#__codelineno-21-117"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-118" name="__codelineno-21-118" href="#__codelineno-21-118"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="n">take</span><span class="p">().</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="n">old_rear</span><span class="o">|</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-119" name="__codelineno-21-119" href="#__codelineno-21-119"></a><span class="w"> </span><span class="k">match</span><span class="w"> </span><span class="n">old_rear</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">prev</span><span class="p">.</span><span class="n">take</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-120" name="__codelineno-21-120" href="#__codelineno-21-120"></a><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">new_rear</span><span class="p">)</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-121" name="__codelineno-21-121" href="#__codelineno-21-121"></a><span class="w"> </span><span class="n">new_rear</span><span class="p">.</span><span class="n">borrow_mut</span><span class="p">().</span><span class="n">next</span><span class="p">.</span><span class="n">take</span><span class="p">();</span>
<a id="__codelineno-21-122" name="__codelineno-21-122" href="#__codelineno-21-122"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">new_rear</span><span class="p">);</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-21-123" name="__codelineno-21-123" href="#__codelineno-21-123"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-124" name="__codelineno-21-124" href="#__codelineno-21-124"></a><span class="w"> </span><span class="nb">None</span><span class="w"> </span><span class="o">=&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-125" name="__codelineno-21-125" href="#__codelineno-21-125"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="n">take</span><span class="p">();</span>
<a id="__codelineno-21-126" name="__codelineno-21-126" href="#__codelineno-21-126"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-127" name="__codelineno-21-127" href="#__codelineno-21-127"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-128" name="__codelineno-21-128" href="#__codelineno-21-128"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-21-129" name="__codelineno-21-129" href="#__codelineno-21-129"></a><span class="w"> </span><span class="n">Rc</span>::<span class="n">try_unwrap</span><span class="p">(</span><span class="n">old_rear</span><span class="p">).</span><span class="n">ok</span><span class="p">().</span><span class="n">unwrap</span><span class="p">().</span><span class="n">into_inner</span><span class="p">().</span><span class="n">val</span>
<a id="__codelineno-21-130" name="__codelineno-21-130" href="#__codelineno-21-130"></a><span class="w"> </span><span class="p">})</span>
<a id="__codelineno-21-131" name="__codelineno-21-131" href="#__codelineno-21-131"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-132" name="__codelineno-21-132" href="#__codelineno-21-132"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-133" name="__codelineno-21-133" href="#__codelineno-21-133"></a>
<a id="__codelineno-21-134" name="__codelineno-21-134" href="#__codelineno-21-134"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-21-135" name="__codelineno-21-135" href="#__codelineno-21-135"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">pop_first</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Option</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-136" name="__codelineno-21-136" href="#__codelineno-21-136"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-21-137" name="__codelineno-21-137" href="#__codelineno-21-137"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-138" name="__codelineno-21-138" href="#__codelineno-21-138"></a>
<a id="__codelineno-21-139" name="__codelineno-21-139" href="#__codelineno-21-139"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-21-140" name="__codelineno-21-140" href="#__codelineno-21-140"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">pop_last</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Option</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-141" name="__codelineno-21-141" href="#__codelineno-21-141"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-21-142" name="__codelineno-21-142" href="#__codelineno-21-142"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-143" name="__codelineno-21-143" href="#__codelineno-21-143"></a>
<a id="__codelineno-21-144" name="__codelineno-21-144" href="#__codelineno-21-144"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-21-145" name="__codelineno-21-145" href="#__codelineno-21-145"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">peek_first</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Option</span><span class="o">&lt;&amp;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-146" name="__codelineno-21-146" href="#__codelineno-21-146"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="n">as_ref</span><span class="p">()</span>
<a id="__codelineno-21-147" name="__codelineno-21-147" href="#__codelineno-21-147"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-148" name="__codelineno-21-148" href="#__codelineno-21-148"></a>
<a id="__codelineno-21-149" name="__codelineno-21-149" href="#__codelineno-21-149"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-21-150" name="__codelineno-21-150" href="#__codelineno-21-150"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">peek_last</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Option</span><span class="o">&lt;&amp;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-151" name="__codelineno-21-151" href="#__codelineno-21-151"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="n">as_ref</span><span class="p">()</span>
<a id="__codelineno-21-152" name="__codelineno-21-152" href="#__codelineno-21-152"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-153" name="__codelineno-21-153" href="#__codelineno-21-153"></a>
<a id="__codelineno-21-154" name="__codelineno-21-154" href="#__codelineno-21-154"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-21-155" name="__codelineno-21-155" href="#__codelineno-21-155"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">to_array</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">head</span>: <span class="nb">Option</span><span class="o">&lt;&amp;</span><span class="n">Rc</span><span class="o">&lt;</span><span class="n">RefCell</span><span class="o">&lt;</span><span class="n">ListNode</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;&gt;&gt;&gt;</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Vec</span><span class="o">&lt;</span><span class="n">T</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-156" name="__codelineno-21-156" href="#__codelineno-21-156"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="n">node</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">head</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-157" name="__codelineno-21-157" href="#__codelineno-21-157"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">to_array</span><span class="p">(</span><span class="n">node</span><span class="p">.</span><span class="n">borrow</span><span class="p">().</span><span class="n">next</span><span class="p">.</span><span class="n">as_ref</span><span class="p">());</span>
<a id="__codelineno-21-158" name="__codelineno-21-158" href="#__codelineno-21-158"></a><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">insert</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">borrow</span><span class="p">().</span><span class="n">val</span><span class="p">);</span>
<a id="__codelineno-21-159" name="__codelineno-21-159" href="#__codelineno-21-159"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span>
<a id="__codelineno-21-160" name="__codelineno-21-160" href="#__codelineno-21-160"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-161" name="__codelineno-21-161" href="#__codelineno-21-161"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nb">Vec</span>::<span class="n">new</span><span class="p">();</span>
<a id="__codelineno-21-162" name="__codelineno-21-162" href="#__codelineno-21-162"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-163" name="__codelineno-21-163" href="#__codelineno-21-163"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.c</span><pre><span></span><code><a id="__codelineno-22-1" name="__codelineno-22-1" href="#__codelineno-22-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-22-2" name="__codelineno-22-2" href="#__codelineno-22-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-3" name="__codelineno-22-3" href="#__codelineno-22-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-22-4" name="__codelineno-22-4" href="#__codelineno-22-4"></a><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点</span>
<a id="__codelineno-22-5" name="__codelineno-22-5" href="#__codelineno-22-5"></a><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点</span>
<a id="__codelineno-22-6" name="__codelineno-22-6" href="#__codelineno-22-6"></a><span class="p">};</span>
<a id="__codelineno-22-7" name="__codelineno-22-7" href="#__codelineno-22-7"></a>
<a id="__codelineno-22-8" name="__codelineno-22-8" href="#__codelineno-22-8"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="n">doublyListNode</span><span class="p">;</span>
<a id="__codelineno-22-9" name="__codelineno-22-9" href="#__codelineno-22-9"></a>
<a id="__codelineno-22-10" name="__codelineno-22-10" href="#__codelineno-22-10"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-22-11" name="__codelineno-22-11" href="#__codelineno-22-11"></a><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="nf">newDoublyListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-12" name="__codelineno-22-12" href="#__codelineno-22-12"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">new</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">doublyListNode</span><span class="p">));</span>
<a id="__codelineno-22-13" name="__codelineno-22-13" href="#__codelineno-22-13"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-22-14" name="__codelineno-22-14" href="#__codelineno-22-14"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-15" name="__codelineno-22-15" href="#__codelineno-22-15"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-16" name="__codelineno-22-16" href="#__codelineno-22-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">new</span><span class="p">;</span>
<a id="__codelineno-22-17" name="__codelineno-22-17" href="#__codelineno-22-17"></a><span class="p">}</span>
<a id="__codelineno-22-18" name="__codelineno-22-18" href="#__codelineno-22-18"></a>
<a id="__codelineno-22-19" name="__codelineno-22-19" href="#__codelineno-22-19"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-22-20" name="__codelineno-22-20" href="#__codelineno-22-20"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delDoublyListNode</span><span class="p">(</span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-21" name="__codelineno-22-21" href="#__codelineno-22-21"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-22-22" name="__codelineno-22-22" href="#__codelineno-22-22"></a><span class="p">}</span>
<a id="__codelineno-22-23" name="__codelineno-22-23" href="#__codelineno-22-23"></a>
<a id="__codelineno-22-24" name="__codelineno-22-24" href="#__codelineno-22-24"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-22-25" name="__codelineno-22-25" href="#__codelineno-22-25"></a><span class="k">struct</span><span class="w"> </span><span class="nc">linkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-26" name="__codelineno-22-26" href="#__codelineno-22-26"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ,尾节点 rear</span>
<a id="__codelineno-22-27" name="__codelineno-22-27" href="#__codelineno-22-27"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-22-28" name="__codelineno-22-28" href="#__codelineno-22-28"></a><span class="p">};</span>
<a id="__codelineno-22-29" name="__codelineno-22-29" href="#__codelineno-22-29"></a>
<a id="__codelineno-22-30" name="__codelineno-22-30" href="#__codelineno-22-30"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">linkedListDeque</span><span class="w"> </span><span class="n">linkedListDeque</span><span class="p">;</span>
<a id="__codelineno-22-31" name="__codelineno-22-31" href="#__codelineno-22-31"></a>
<a id="__codelineno-22-32" name="__codelineno-22-32" href="#__codelineno-22-32"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-22-33" name="__codelineno-22-33" href="#__codelineno-22-33"></a><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="nf">newLinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-34" name="__codelineno-22-34" href="#__codelineno-22-34"></a><span class="w"> </span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="p">));</span>
<a id="__codelineno-22-35" name="__codelineno-22-35" href="#__codelineno-22-35"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-36" name="__codelineno-22-36" href="#__codelineno-22-36"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-37" name="__codelineno-22-37" href="#__codelineno-22-37"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-22-38" name="__codelineno-22-38" href="#__codelineno-22-38"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-22-39" name="__codelineno-22-39" href="#__codelineno-22-39"></a><span class="p">}</span>
<a id="__codelineno-22-40" name="__codelineno-22-40" href="#__codelineno-22-40"></a>
<a id="__codelineno-22-41" name="__codelineno-22-41" href="#__codelineno-22-41"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-22-42" name="__codelineno-22-42" href="#__codelineno-22-42"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delLinkedListdeque</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-43" name="__codelineno-22-43" href="#__codelineno-22-43"></a><span class="w"> </span><span class="c1">// 释放所有节点</span>
<a id="__codelineno-22-44" name="__codelineno-22-44" href="#__codelineno-22-44"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-45" name="__codelineno-22-45" href="#__codelineno-22-45"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">tmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-22-46" name="__codelineno-22-46" href="#__codelineno-22-46"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-22-47" name="__codelineno-22-47" href="#__codelineno-22-47"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">tmp</span><span class="p">);</span>
<a id="__codelineno-22-48" name="__codelineno-22-48" href="#__codelineno-22-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-49" name="__codelineno-22-49" href="#__codelineno-22-49"></a><span class="w"> </span><span class="c1">// 释放 deque 结构体</span>
<a id="__codelineno-22-50" name="__codelineno-22-50" href="#__codelineno-22-50"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-22-51" name="__codelineno-22-51" href="#__codelineno-22-51"></a><span class="p">}</span>
<a id="__codelineno-22-52" name="__codelineno-22-52" href="#__codelineno-22-52"></a>
<a id="__codelineno-22-53" name="__codelineno-22-53" href="#__codelineno-22-53"></a><span class="cm">/* 获取队列的长度 */</span>
<a id="__codelineno-22-54" name="__codelineno-22-54" href="#__codelineno-22-54"></a><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-55" name="__codelineno-22-55" href="#__codelineno-22-55"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-22-56" name="__codelineno-22-56" href="#__codelineno-22-56"></a><span class="p">}</span>
<a id="__codelineno-22-57" name="__codelineno-22-57" href="#__codelineno-22-57"></a>
<a id="__codelineno-22-58" name="__codelineno-22-58" href="#__codelineno-22-58"></a><span class="cm">/* 判断队列是否为空 */</span>
<a id="__codelineno-22-59" name="__codelineno-22-59" href="#__codelineno-22-59"></a><span class="kt">bool</span><span class="w"> </span><span class="nf">empty</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-60" name="__codelineno-22-60" href="#__codelineno-22-60"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-22-61" name="__codelineno-22-61" href="#__codelineno-22-61"></a><span class="p">}</span>
<a id="__codelineno-22-62" name="__codelineno-22-62" href="#__codelineno-22-62"></a>
<a id="__codelineno-22-63" name="__codelineno-22-63" href="#__codelineno-22-63"></a><span class="cm">/* 入队 */</span>
<a id="__codelineno-22-64" name="__codelineno-22-64" href="#__codelineno-22-64"></a><span class="kt">void</span><span class="w"> </span><span class="nf">push</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-65" name="__codelineno-22-65" href="#__codelineno-22-65"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">newDoublyListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-22-66" name="__codelineno-22-66" href="#__codelineno-22-66"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向node</span>
<a id="__codelineno-22-67" name="__codelineno-22-67" href="#__codelineno-22-67"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-68" name="__codelineno-22-68" href="#__codelineno-22-68"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-22-69" name="__codelineno-22-69" href="#__codelineno-22-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-70" name="__codelineno-22-70" href="#__codelineno-22-70"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-22-71" name="__codelineno-22-71" href="#__codelineno-22-71"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-72" name="__codelineno-22-72" href="#__codelineno-22-72"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-22-73" name="__codelineno-22-73" href="#__codelineno-22-73"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-22-74" name="__codelineno-22-74" href="#__codelineno-22-74"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-22-75" name="__codelineno-22-75" href="#__codelineno-22-75"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-22-76" name="__codelineno-22-76" href="#__codelineno-22-76"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-77" name="__codelineno-22-77" href="#__codelineno-22-77"></a><span class="w"> </span><span class="c1">// 对尾入队操作</span>
<a id="__codelineno-22-78" name="__codelineno-22-78" href="#__codelineno-22-78"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-79" name="__codelineno-22-79" href="#__codelineno-22-79"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-22-80" name="__codelineno-22-80" href="#__codelineno-22-80"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-22-81" name="__codelineno-22-81" href="#__codelineno-22-81"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-22-82" name="__codelineno-22-82" href="#__codelineno-22-82"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-22-83" name="__codelineno-22-83" href="#__codelineno-22-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-84" name="__codelineno-22-84" href="#__codelineno-22-84"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-22-85" name="__codelineno-22-85" href="#__codelineno-22-85"></a><span class="p">}</span>
<a id="__codelineno-22-86" name="__codelineno-22-86" href="#__codelineno-22-86"></a>
<a id="__codelineno-22-87" name="__codelineno-22-87" href="#__codelineno-22-87"></a><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-22-88" name="__codelineno-22-88" href="#__codelineno-22-88"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-89" name="__codelineno-22-89" href="#__codelineno-22-89"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-22-90" name="__codelineno-22-90" href="#__codelineno-22-90"></a><span class="p">}</span>
<a id="__codelineno-22-91" name="__codelineno-22-91" href="#__codelineno-22-91"></a>
<a id="__codelineno-22-92" name="__codelineno-22-92" href="#__codelineno-22-92"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-22-93" name="__codelineno-22-93" href="#__codelineno-22-93"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-94" name="__codelineno-22-94" href="#__codelineno-22-94"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-22-95" name="__codelineno-22-95" href="#__codelineno-22-95"></a><span class="p">}</span>
<a id="__codelineno-22-96" name="__codelineno-22-96" href="#__codelineno-22-96"></a>
<a id="__codelineno-22-97" name="__codelineno-22-97" href="#__codelineno-22-97"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-22-98" name="__codelineno-22-98" href="#__codelineno-22-98"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-99" name="__codelineno-22-99" href="#__codelineno-22-99"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">);</span>
<a id="__codelineno-22-100" name="__codelineno-22-100" href="#__codelineno-22-100"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-22-101" name="__codelineno-22-101" href="#__codelineno-22-101"></a><span class="p">}</span>
<a id="__codelineno-22-102" name="__codelineno-22-102" href="#__codelineno-22-102"></a>
<a id="__codelineno-22-103" name="__codelineno-22-103" href="#__codelineno-22-103"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-22-104" name="__codelineno-22-104" href="#__codelineno-22-104"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-105" name="__codelineno-22-105" href="#__codelineno-22-105"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">);</span>
<a id="__codelineno-22-106" name="__codelineno-22-106" href="#__codelineno-22-106"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-22-107" name="__codelineno-22-107" href="#__codelineno-22-107"></a><span class="p">}</span>
<a id="__codelineno-22-108" name="__codelineno-22-108" href="#__codelineno-22-108"></a>
<a id="__codelineno-22-109" name="__codelineno-22-109" href="#__codelineno-22-109"></a><span class="cm">/* 出队 */</span>
<a id="__codelineno-22-110" name="__codelineno-22-110" href="#__codelineno-22-110"></a><span class="kt">int</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-111" name="__codelineno-22-111" href="#__codelineno-22-111"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span>
<a id="__codelineno-22-112" name="__codelineno-22-112" href="#__codelineno-22-112"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<a id="__codelineno-22-113" name="__codelineno-22-113" href="#__codelineno-22-113"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-22-114" name="__codelineno-22-114" href="#__codelineno-22-114"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-22-115" name="__codelineno-22-115" href="#__codelineno-22-115"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-116" name="__codelineno-22-116" href="#__codelineno-22-116"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-22-117" name="__codelineno-22-117" href="#__codelineno-22-117"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-22-118" name="__codelineno-22-118" href="#__codelineno-22-118"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-119" name="__codelineno-22-119" href="#__codelineno-22-119"></a><span class="w"> </span><span class="n">fNext</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-120" name="__codelineno-22-120" href="#__codelineno-22-120"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-121" name="__codelineno-22-121" href="#__codelineno-22-121"></a><span class="w"> </span><span class="n">delDoublyListNode</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">);</span>
<a id="__codelineno-22-122" name="__codelineno-22-122" href="#__codelineno-22-122"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-123" name="__codelineno-22-123" href="#__codelineno-22-123"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-22-124" name="__codelineno-22-124" href="#__codelineno-22-124"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-125" name="__codelineno-22-125" href="#__codelineno-22-125"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-22-126" name="__codelineno-22-126" href="#__codelineno-22-126"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-127" name="__codelineno-22-127" href="#__codelineno-22-127"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-22-128" name="__codelineno-22-128" href="#__codelineno-22-128"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-22-129" name="__codelineno-22-129" href="#__codelineno-22-129"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-130" name="__codelineno-22-130" href="#__codelineno-22-130"></a><span class="w"> </span><span class="n">rPrev</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-131" name="__codelineno-22-131" href="#__codelineno-22-131"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-22-132" name="__codelineno-22-132" href="#__codelineno-22-132"></a><span class="w"> </span><span class="n">delDoublyListNode</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">);</span>
<a id="__codelineno-22-133" name="__codelineno-22-133" href="#__codelineno-22-133"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-134" name="__codelineno-22-134" href="#__codelineno-22-134"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-22-135" name="__codelineno-22-135" href="#__codelineno-22-135"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-136" name="__codelineno-22-136" href="#__codelineno-22-136"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-22-137" name="__codelineno-22-137" href="#__codelineno-22-137"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-22-138" name="__codelineno-22-138" href="#__codelineno-22-138"></a><span class="p">}</span>
<a id="__codelineno-22-139" name="__codelineno-22-139" href="#__codelineno-22-139"></a>
<a id="__codelineno-22-140" name="__codelineno-22-140" href="#__codelineno-22-140"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-22-141" name="__codelineno-22-141" href="#__codelineno-22-141"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-142" name="__codelineno-22-142" href="#__codelineno-22-142"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-22-143" name="__codelineno-22-143" href="#__codelineno-22-143"></a><span class="p">}</span>
<a id="__codelineno-22-144" name="__codelineno-22-144" href="#__codelineno-22-144"></a>
<a id="__codelineno-22-145" name="__codelineno-22-145" href="#__codelineno-22-145"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-22-146" name="__codelineno-22-146" href="#__codelineno-22-146"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-147" name="__codelineno-22-147" href="#__codelineno-22-147"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-22-148" name="__codelineno-22-148" href="#__codelineno-22-148"></a><span class="p">}</span>
<a id="__codelineno-22-149" name="__codelineno-22-149" href="#__codelineno-22-149"></a>
<a id="__codelineno-22-150" name="__codelineno-22-150" href="#__codelineno-22-150"></a><span class="cm">/* 打印队列 */</span>
<a id="__codelineno-22-151" name="__codelineno-22-151" href="#__codelineno-22-151"></a><span class="kt">void</span><span class="w"> </span><span class="nf">printLinkedListDeque</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-152" name="__codelineno-22-152" href="#__codelineno-22-152"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-22-153" name="__codelineno-22-153" href="#__codelineno-22-153"></a><span class="w"> </span><span class="c1">// 拷贝链表中的数据到数组</span>
<a id="__codelineno-22-154" name="__codelineno-22-154" href="#__codelineno-22-154"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-22-155" name="__codelineno-22-155" href="#__codelineno-22-155"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-22-156" name="__codelineno-22-156" href="#__codelineno-22-156"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-22-157" name="__codelineno-22-157" href="#__codelineno-22-157"></a><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-22-158" name="__codelineno-22-158" href="#__codelineno-22-158"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-22-159" name="__codelineno-22-159" href="#__codelineno-22-159"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-22-160" name="__codelineno-22-160" href="#__codelineno-22-160"></a><span class="w"> </span><span class="n">printArray</span><span class="p">(</span><span class="n">arr</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-22-161" name="__codelineno-22-161" href="#__codelineno-22-161"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.zig</span><pre><span></span><code><a id="__codelineno-23-1" name="__codelineno-23-1" href="#__codelineno-23-1"></a><span class="c1">// 双向链表节点</span>
<a id="__codelineno-23-2" name="__codelineno-23-2" href="#__codelineno-23-2"></a><span class="k">fn</span><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="kr">comptime</span><span class="w"> </span><span class="n">T</span><span class="o">:</span><span class="w"> </span><span class="kt">type</span><span class="p">)</span><span class="w"> </span><span class="kt">type</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-3" name="__codelineno-23-3" href="#__codelineno-23-3"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-4" name="__codelineno-23-4" href="#__codelineno-23-4"></a><span class="w"> </span><span class="kr">const</span><span class="w"> </span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">@This</span><span class="p">();</span>
<a id="__codelineno-23-5" name="__codelineno-23-5" href="#__codelineno-23-5"></a>
<a id="__codelineno-23-6" name="__codelineno-23-6" href="#__codelineno-23-6"></a><span class="w"> </span><span class="n">val</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">,</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-23-7" name="__codelineno-23-7" href="#__codelineno-23-7"></a><span class="w"> </span><span class="n">next</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 后继节点指针</span>
<a id="__codelineno-23-8" name="__codelineno-23-8" href="#__codelineno-23-8"></a><span class="w"> </span><span class="n">prev</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 前驱节点指针</span>
<a id="__codelineno-23-9" name="__codelineno-23-9" href="#__codelineno-23-9"></a>
<a id="__codelineno-23-10" name="__codelineno-23-10" href="#__codelineno-23-10"></a><span class="w"> </span><span class="c1">// Initialize a list node with specific value</span>
<a id="__codelineno-23-11" name="__codelineno-23-11" href="#__codelineno-23-11"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">init</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">x</span><span class="o">:</span><span class="w"> </span><span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-12" name="__codelineno-23-12" href="#__codelineno-23-12"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">x</span><span class="p">;</span>
<a id="__codelineno-23-13" name="__codelineno-23-13" href="#__codelineno-23-13"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-14" name="__codelineno-23-14" href="#__codelineno-23-14"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-15" name="__codelineno-23-15" href="#__codelineno-23-15"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-16" name="__codelineno-23-16" href="#__codelineno-23-16"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-23-17" name="__codelineno-23-17" href="#__codelineno-23-17"></a><span class="p">}</span>
<a id="__codelineno-23-18" name="__codelineno-23-18" href="#__codelineno-23-18"></a>
<a id="__codelineno-23-19" name="__codelineno-23-19" href="#__codelineno-23-19"></a><span class="c1">// 基于双向链表实现的双向队列</span>
<a id="__codelineno-23-20" name="__codelineno-23-20" href="#__codelineno-23-20"></a><span class="k">fn</span><span class="w"> </span><span class="n">LinkedListDeque</span><span class="p">(</span><span class="kr">comptime</span><span class="w"> </span><span class="n">T</span><span class="o">:</span><span class="w"> </span><span class="kt">type</span><span class="p">)</span><span class="w"> </span><span class="kt">type</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-21" name="__codelineno-23-21" href="#__codelineno-23-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-22" name="__codelineno-23-22" href="#__codelineno-23-22"></a><span class="w"> </span><span class="kr">const</span><span class="w"> </span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">@This</span><span class="p">();</span>
<a id="__codelineno-23-23" name="__codelineno-23-23" href="#__codelineno-23-23"></a>
<a id="__codelineno-23-24" name="__codelineno-23-24" href="#__codelineno-23-24"></a><span class="w"> </span><span class="n">front</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-23-25" name="__codelineno-23-25" href="#__codelineno-23-25"></a><span class="w"> </span><span class="n">rear</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-23-26" name="__codelineno-23-26" href="#__codelineno-23-26"></a><span class="w"> </span><span class="n">que_size</span><span class="o">:</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-23-27" name="__codelineno-23-27" href="#__codelineno-23-27"></a><span class="w"> </span><span class="n">mem_arena</span><span class="o">:</span><span class="w"> </span><span class="o">?</span><span class="n">std</span><span class="p">.</span><span class="n">heap</span><span class="p">.</span><span class="n">ArenaAllocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span>
<a id="__codelineno-23-28" name="__codelineno-23-28" href="#__codelineno-23-28"></a><span class="w"> </span><span class="n">mem_allocator</span><span class="o">:</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">mem</span><span class="p">.</span><span class="n">Allocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">,</span><span class="w"> </span><span class="c1">// 内存分配器</span>
<a id="__codelineno-23-29" name="__codelineno-23-29" href="#__codelineno-23-29"></a>
<a id="__codelineno-23-30" name="__codelineno-23-30" href="#__codelineno-23-30"></a><span class="w"> </span><span class="c1">// 构造函数(分配内存+初始化队列)</span>
<a id="__codelineno-23-31" name="__codelineno-23-31" href="#__codelineno-23-31"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">init</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">allocator</span><span class="o">:</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">mem</span><span class="p">.</span><span class="n">Allocator</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-32" name="__codelineno-23-32" href="#__codelineno-23-32"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-33" name="__codelineno-23-33" href="#__codelineno-23-33"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">heap</span><span class="p">.</span><span class="n">ArenaAllocator</span><span class="p">.</span><span class="n">init</span><span class="p">(</span><span class="n">allocator</span><span class="p">);</span>
<a id="__codelineno-23-34" name="__codelineno-23-34" href="#__codelineno-23-34"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">allocator</span><span class="p">();</span>
<a id="__codelineno-23-35" name="__codelineno-23-35" href="#__codelineno-23-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-36" name="__codelineno-23-36" href="#__codelineno-23-36"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-37" name="__codelineno-23-37" href="#__codelineno-23-37"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-38" name="__codelineno-23-38" href="#__codelineno-23-38"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-23-39" name="__codelineno-23-39" href="#__codelineno-23-39"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-40" name="__codelineno-23-40" href="#__codelineno-23-40"></a>
<a id="__codelineno-23-41" name="__codelineno-23-41" href="#__codelineno-23-41"></a><span class="w"> </span><span class="c1">// 析构函数(释放内存)</span>
<a id="__codelineno-23-42" name="__codelineno-23-42" href="#__codelineno-23-42"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">deinit</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-43" name="__codelineno-23-43" href="#__codelineno-23-43"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-23-44" name="__codelineno-23-44" href="#__codelineno-23-44"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">deinit</span><span class="p">();</span>
<a id="__codelineno-23-45" name="__codelineno-23-45" href="#__codelineno-23-45"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-46" name="__codelineno-23-46" href="#__codelineno-23-46"></a>
<a id="__codelineno-23-47" name="__codelineno-23-47" href="#__codelineno-23-47"></a><span class="w"> </span><span class="c1">// 获取双向队列的长度</span>
<a id="__codelineno-23-48" name="__codelineno-23-48" href="#__codelineno-23-48"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">size</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-49" name="__codelineno-23-49" href="#__codelineno-23-49"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="p">;</span>
<a id="__codelineno-23-50" name="__codelineno-23-50" href="#__codelineno-23-50"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-51" name="__codelineno-23-51" href="#__codelineno-23-51"></a>
<a id="__codelineno-23-52" name="__codelineno-23-52" href="#__codelineno-23-52"></a><span class="w"> </span><span class="c1">// 判断双向队列是否为空</span>
<a id="__codelineno-23-53" name="__codelineno-23-53" href="#__codelineno-23-53"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-54" name="__codelineno-23-54" href="#__codelineno-23-54"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-23-55" name="__codelineno-23-55" href="#__codelineno-23-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-56" name="__codelineno-23-56" href="#__codelineno-23-56"></a>
<a id="__codelineno-23-57" name="__codelineno-23-57" href="#__codelineno-23-57"></a><span class="w"> </span><span class="c1">// 入队操作</span>
<a id="__codelineno-23-58" name="__codelineno-23-58" href="#__codelineno-23-58"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span><span class="o">:</span><span class="w"> </span><span class="kt">bool</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-59" name="__codelineno-23-59" href="#__codelineno-23-59"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="p">.</span><span class="n">create</span><span class="p">(</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">));</span>
<a id="__codelineno-23-60" name="__codelineno-23-60" href="#__codelineno-23-60"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">init</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-23-61" name="__codelineno-23-61" href="#__codelineno-23-61"></a><span class="w"> </span><span class="c1">// 若链表为空,则令 front, rear 都指向 node</span>
<a id="__codelineno-23-62" name="__codelineno-23-62" href="#__codelineno-23-62"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-63" name="__codelineno-23-63" href="#__codelineno-23-63"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-23-64" name="__codelineno-23-64" href="#__codelineno-23-64"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-23-65" name="__codelineno-23-65" href="#__codelineno-23-65"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-23-66" name="__codelineno-23-66" href="#__codelineno-23-66"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">is_front</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-67" name="__codelineno-23-67" href="#__codelineno-23-67"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-23-68" name="__codelineno-23-68" href="#__codelineno-23-68"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-23-69" name="__codelineno-23-69" href="#__codelineno-23-69"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-23-70" name="__codelineno-23-70" href="#__codelineno-23-70"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-23-71" name="__codelineno-23-71" href="#__codelineno-23-71"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-23-72" name="__codelineno-23-72" href="#__codelineno-23-72"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-73" name="__codelineno-23-73" href="#__codelineno-23-73"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-23-74" name="__codelineno-23-74" href="#__codelineno-23-74"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-23-75" name="__codelineno-23-75" href="#__codelineno-23-75"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-23-76" name="__codelineno-23-76" href="#__codelineno-23-76"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-23-77" name="__codelineno-23-77" href="#__codelineno-23-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-78" name="__codelineno-23-78" href="#__codelineno-23-78"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-23-79" name="__codelineno-23-79" href="#__codelineno-23-79"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-80" name="__codelineno-23-80" href="#__codelineno-23-80"></a>
<a id="__codelineno-23-81" name="__codelineno-23-81" href="#__codelineno-23-81"></a><span class="w"> </span><span class="c1">// 队首入队</span>
<a id="__codelineno-23-82" name="__codelineno-23-82" href="#__codelineno-23-82"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-83" name="__codelineno-23-83" href="#__codelineno-23-83"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-23-84" name="__codelineno-23-84" href="#__codelineno-23-84"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-85" name="__codelineno-23-85" href="#__codelineno-23-85"></a>
<a id="__codelineno-23-86" name="__codelineno-23-86" href="#__codelineno-23-86"></a><span class="w"> </span><span class="c1">// 队尾入队</span>
<a id="__codelineno-23-87" name="__codelineno-23-87" href="#__codelineno-23-87"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-88" name="__codelineno-23-88" href="#__codelineno-23-88"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-23-89" name="__codelineno-23-89" href="#__codelineno-23-89"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-90" name="__codelineno-23-90" href="#__codelineno-23-90"></a>
<a id="__codelineno-23-91" name="__codelineno-23-91" href="#__codelineno-23-91"></a><span class="w"> </span><span class="c1">// 出队操作</span>
<a id="__codelineno-23-92" name="__codelineno-23-92" href="#__codelineno-23-92"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span><span class="o">:</span><span class="w"> </span><span class="kt">bool</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-93" name="__codelineno-23-93" href="#__codelineno-23-93"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-23-94" name="__codelineno-23-94" href="#__codelineno-23-94"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">val</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">;</span>
<a id="__codelineno-23-95" name="__codelineno-23-95" href="#__codelineno-23-95"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-23-96" name="__codelineno-23-96" href="#__codelineno-23-96"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">is_front</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-97" name="__codelineno-23-97" href="#__codelineno-23-97"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-23-98" name="__codelineno-23-98" href="#__codelineno-23-98"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-23-99" name="__codelineno-23-99" href="#__codelineno-23-99"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-23-100" name="__codelineno-23-100" href="#__codelineno-23-100"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-101" name="__codelineno-23-101" href="#__codelineno-23-101"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-102" name="__codelineno-23-102" href="#__codelineno-23-102"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-103" name="__codelineno-23-103" href="#__codelineno-23-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-104" name="__codelineno-23-104" href="#__codelineno-23-104"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-23-105" name="__codelineno-23-105" href="#__codelineno-23-105"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-23-106" name="__codelineno-23-106" href="#__codelineno-23-106"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-107" name="__codelineno-23-107" href="#__codelineno-23-107"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-23-108" name="__codelineno-23-108" href="#__codelineno-23-108"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-23-109" name="__codelineno-23-109" href="#__codelineno-23-109"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-23-110" name="__codelineno-23-110" href="#__codelineno-23-110"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-111" name="__codelineno-23-111" href="#__codelineno-23-111"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-112" name="__codelineno-23-112" href="#__codelineno-23-112"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-23-113" name="__codelineno-23-113" href="#__codelineno-23-113"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-114" name="__codelineno-23-114" href="#__codelineno-23-114"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-23-115" name="__codelineno-23-115" href="#__codelineno-23-115"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-116" name="__codelineno-23-116" href="#__codelineno-23-116"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-23-117" name="__codelineno-23-117" href="#__codelineno-23-117"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-23-118" name="__codelineno-23-118" href="#__codelineno-23-118"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-119" name="__codelineno-23-119" href="#__codelineno-23-119"></a>
<a id="__codelineno-23-120" name="__codelineno-23-120" href="#__codelineno-23-120"></a><span class="w"> </span><span class="c1">// 队首出队</span>
<a id="__codelineno-23-121" name="__codelineno-23-121" href="#__codelineno-23-121"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">popFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-122" name="__codelineno-23-122" href="#__codelineno-23-122"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-23-123" name="__codelineno-23-123" href="#__codelineno-23-123"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-124" name="__codelineno-23-124" href="#__codelineno-23-124"></a>
<a id="__codelineno-23-125" name="__codelineno-23-125" href="#__codelineno-23-125"></a><span class="w"> </span><span class="c1">// 队尾出队</span>
<a id="__codelineno-23-126" name="__codelineno-23-126" href="#__codelineno-23-126"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">popLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-127" name="__codelineno-23-127" href="#__codelineno-23-127"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-23-128" name="__codelineno-23-128" href="#__codelineno-23-128"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-129" name="__codelineno-23-129" href="#__codelineno-23-129"></a>
<a id="__codelineno-23-130" name="__codelineno-23-130" href="#__codelineno-23-130"></a><span class="w"> </span><span class="c1">// 访问队首元素</span>
<a id="__codelineno-23-131" name="__codelineno-23-131" href="#__codelineno-23-131"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-132" name="__codelineno-23-132" href="#__codelineno-23-132"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-23-133" name="__codelineno-23-133" href="#__codelineno-23-133"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-23-134" name="__codelineno-23-134" href="#__codelineno-23-134"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-23-135" name="__codelineno-23-135" href="#__codelineno-23-135"></a>
<a id="__codelineno-23-136" name="__codelineno-23-136" href="#__codelineno-23-136"></a><span class="w"> </span><span class="c1">// 访问队尾元素</span>
<a id="__codelineno-23-137" name="__codelineno-23-137" href="#__codelineno-23-137"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-138" name="__codelineno-23-138" href="#__codelineno-23-138"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-23-139" name="__codelineno-23-139" href="#__codelineno-23-139"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-23-140" name="__codelineno-23-140" href="#__codelineno-23-140"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-141" name="__codelineno-23-141" href="#__codelineno-23-141"></a>
<a id="__codelineno-23-142" name="__codelineno-23-142" href="#__codelineno-23-142"></a><span class="w"> </span><span class="c1">// 返回数组用于打印</span>
<a id="__codelineno-23-143" name="__codelineno-23-143" href="#__codelineno-23-143"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">toArray</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="p">[]</span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-144" name="__codelineno-23-144" href="#__codelineno-23-144"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-23-145" name="__codelineno-23-145" href="#__codelineno-23-145"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="p">.</span><span class="n">alloc</span><span class="p">(</span><span class="n">T</span><span class="p">,</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">());</span>
<a id="__codelineno-23-146" name="__codelineno-23-146" href="#__codelineno-23-146"></a><span class="w"> </span><span class="nb">@memset</span><span class="p">(</span><span class="n">res</span><span class="p">,</span><span class="w"> </span><span class="nb">@as</span><span class="p">(</span><span class="n">T</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">));</span>
<a id="__codelineno-23-147" name="__codelineno-23-147" href="#__codelineno-23-147"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">i</span><span class="o">:</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-23-148" name="__codelineno-23-148" href="#__codelineno-23-148"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">len</span><span class="p">)</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-149" name="__codelineno-23-149" href="#__codelineno-23-149"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-23-150" name="__codelineno-23-150" href="#__codelineno-23-150"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-23-151" name="__codelineno-23-151" href="#__codelineno-23-151"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-152" name="__codelineno-23-152" href="#__codelineno-23-152"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-23-153" name="__codelineno-23-153" href="#__codelineno-23-153"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-154" name="__codelineno-23-154" href="#__codelineno-23-154"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-23-155" name="__codelineno-23-155" href="#__codelineno-23-155"></a><span class="p">}</span>
</code></pre></div>
</div>
</div>
</div>
<h3 id="2">2. &nbsp; 基于数组的实现<a class="headerlink" href="#2" title="Permanent link">&para;</a></h3>
<p>如图 5-9 所示,与基于数组实现队列类似,我们也可以使用环形数组来实现双向队列。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:5"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">ArrayDeque</label><label for="__tabbed_4_2">pushLast()</label><label for="__tabbed_4_3">pushFirst()</label><label for="__tabbed_4_4">popLast()</label><label for="__tabbed_4_5">popFirst()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/array_deque.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="基于数组实现双向队列的入队出队操作" src="../deque.assets/array_deque.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/array_deque_push_last.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="array_deque_push_last" src="../deque.assets/array_deque_push_last.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/array_deque_push_first.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="array_deque_push_first" src="../deque.assets/array_deque_push_first.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/array_deque_pop_last.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="array_deque_pop_last" src="../deque.assets/array_deque_pop_last.png" /></a></p>
</div>
<div class="tabbed-block">
<p><a class="glightbox" href="../deque.assets/array_deque_pop_first.png" data-type="image" data-width="100%" data-height="auto" data-desc-position="bottom"><img alt="array_deque_pop_first" src="../deque.assets/array_deque_pop_first.png" /></a></p>
</div>
</div>
</div>
<p align="center"> 图 5-9 &nbsp; 基于数组实现双向队列的入队出队操作 </p>
<p>在队列的实现基础上,仅需增加“队首入队”和“队尾出队”的方法。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="5:12"><input checked="checked" id="__tabbed_5_1" name="__tabbed_5" type="radio" /><input id="__tabbed_5_2" name="__tabbed_5" type="radio" /><input id="__tabbed_5_3" name="__tabbed_5" type="radio" /><input id="__tabbed_5_4" name="__tabbed_5" type="radio" /><input id="__tabbed_5_5" name="__tabbed_5" type="radio" /><input id="__tabbed_5_6" name="__tabbed_5" type="radio" /><input id="__tabbed_5_7" name="__tabbed_5" type="radio" /><input id="__tabbed_5_8" name="__tabbed_5" type="radio" /><input id="__tabbed_5_9" name="__tabbed_5" type="radio" /><input id="__tabbed_5_10" name="__tabbed_5" type="radio" /><input id="__tabbed_5_11" name="__tabbed_5" type="radio" /><input id="__tabbed_5_12" name="__tabbed_5" type="radio" /><div class="tabbed-labels"><label for="__tabbed_5_1">Python</label><label for="__tabbed_5_2">C++</label><label for="__tabbed_5_3">Java</label><label for="__tabbed_5_4">C#</label><label for="__tabbed_5_5">Go</label><label for="__tabbed_5_6">Swift</label><label for="__tabbed_5_7">JS</label><label for="__tabbed_5_8">TS</label><label for="__tabbed_5_9">Dart</label><label for="__tabbed_5_10">Rust</label><label for="__tabbed_5_11">C</label><label for="__tabbed_5_12">Zig</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.py</span><pre><span></span><code><a id="__codelineno-24-1" name="__codelineno-24-1" href="#__codelineno-24-1"></a><span class="k">class</span> <span class="nc">ArrayDeque</span><span class="p">:</span>
<a id="__codelineno-24-2" name="__codelineno-24-2" href="#__codelineno-24-2"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;基于环形数组实现的双向队列&quot;&quot;&quot;</span>
<a id="__codelineno-24-3" name="__codelineno-24-3" href="#__codelineno-24-3"></a>
<a id="__codelineno-24-4" name="__codelineno-24-4" href="#__codelineno-24-4"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">capacity</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-24-5" name="__codelineno-24-5" href="#__codelineno-24-5"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-24-6" name="__codelineno-24-6" href="#__codelineno-24-6"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">*</span> <span class="n">capacity</span>
<a id="__codelineno-24-7" name="__codelineno-24-7" href="#__codelineno-24-7"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-24-8" name="__codelineno-24-8" href="#__codelineno-24-8"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-24-9" name="__codelineno-24-9" href="#__codelineno-24-9"></a>
<a id="__codelineno-24-10" name="__codelineno-24-10" href="#__codelineno-24-10"></a> <span class="k">def</span> <span class="nf">capacity</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-11" name="__codelineno-24-11" href="#__codelineno-24-11"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的容量&quot;&quot;&quot;</span>
<a id="__codelineno-24-12" name="__codelineno-24-12" href="#__codelineno-24-12"></a> <span class="k">return</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">)</span>
<a id="__codelineno-24-13" name="__codelineno-24-13" href="#__codelineno-24-13"></a>
<a id="__codelineno-24-14" name="__codelineno-24-14" href="#__codelineno-24-14"></a> <span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-15" name="__codelineno-24-15" href="#__codelineno-24-15"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的长度&quot;&quot;&quot;</span>
<a id="__codelineno-24-16" name="__codelineno-24-16" href="#__codelineno-24-16"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span>
<a id="__codelineno-24-17" name="__codelineno-24-17" href="#__codelineno-24-17"></a>
<a id="__codelineno-24-18" name="__codelineno-24-18" href="#__codelineno-24-18"></a> <span class="k">def</span> <span class="nf">is_empty</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">bool</span><span class="p">:</span>
<a id="__codelineno-24-19" name="__codelineno-24-19" href="#__codelineno-24-19"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;判断双向队列是否为空&quot;&quot;&quot;</span>
<a id="__codelineno-24-20" name="__codelineno-24-20" href="#__codelineno-24-20"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">==</span> <span class="mi">0</span>
<a id="__codelineno-24-21" name="__codelineno-24-21" href="#__codelineno-24-21"></a>
<a id="__codelineno-24-22" name="__codelineno-24-22" href="#__codelineno-24-22"></a> <span class="k">def</span> <span class="nf">index</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">i</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-23" name="__codelineno-24-23" href="#__codelineno-24-23"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;计算环形数组索引&quot;&quot;&quot;</span>
<a id="__codelineno-24-24" name="__codelineno-24-24" href="#__codelineno-24-24"></a> <span class="c1"># 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-24-25" name="__codelineno-24-25" href="#__codelineno-24-25"></a> <span class="c1"># 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-24-26" name="__codelineno-24-26" href="#__codelineno-24-26"></a> <span class="c1"># 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-24-27" name="__codelineno-24-27" href="#__codelineno-24-27"></a> <span class="k">return</span> <span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">())</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">()</span>
<a id="__codelineno-24-28" name="__codelineno-24-28" href="#__codelineno-24-28"></a>
<a id="__codelineno-24-29" name="__codelineno-24-29" href="#__codelineno-24-29"></a> <span class="k">def</span> <span class="nf">push_first</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-24-30" name="__codelineno-24-30" href="#__codelineno-24-30"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首入队&quot;&quot;&quot;</span>
<a id="__codelineno-24-31" name="__codelineno-24-31" href="#__codelineno-24-31"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">==</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">():</span>
<a id="__codelineno-24-32" name="__codelineno-24-32" href="#__codelineno-24-32"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-24-33" name="__codelineno-24-33" href="#__codelineno-24-33"></a> <span class="k">return</span>
<a id="__codelineno-24-34" name="__codelineno-24-34" href="#__codelineno-24-34"></a> <span class="c1"># 队首指针向左移动一位</span>
<a id="__codelineno-24-35" name="__codelineno-24-35" href="#__codelineno-24-35"></a> <span class="c1"># 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-24-36" name="__codelineno-24-36" href="#__codelineno-24-36"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-24-37" name="__codelineno-24-37" href="#__codelineno-24-37"></a> <span class="c1"># 将 num 添加至队首</span>
<a id="__codelineno-24-38" name="__codelineno-24-38" href="#__codelineno-24-38"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="p">]</span> <span class="o">=</span> <span class="n">num</span>
<a id="__codelineno-24-39" name="__codelineno-24-39" href="#__codelineno-24-39"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-24-40" name="__codelineno-24-40" href="#__codelineno-24-40"></a>
<a id="__codelineno-24-41" name="__codelineno-24-41" href="#__codelineno-24-41"></a> <span class="k">def</span> <span class="nf">push_last</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">):</span>
<a id="__codelineno-24-42" name="__codelineno-24-42" href="#__codelineno-24-42"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾入队&quot;&quot;&quot;</span>
<a id="__codelineno-24-43" name="__codelineno-24-43" href="#__codelineno-24-43"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">==</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">():</span>
<a id="__codelineno-24-44" name="__codelineno-24-44" href="#__codelineno-24-44"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-24-45" name="__codelineno-24-45" href="#__codelineno-24-45"></a> <span class="k">return</span>
<a id="__codelineno-24-46" name="__codelineno-24-46" href="#__codelineno-24-46"></a> <span class="c1"># 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-24-47" name="__codelineno-24-47" href="#__codelineno-24-47"></a> <span class="n">rear</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">)</span>
<a id="__codelineno-24-48" name="__codelineno-24-48" href="#__codelineno-24-48"></a> <span class="c1"># 将 num 添加至队尾</span>
<a id="__codelineno-24-49" name="__codelineno-24-49" href="#__codelineno-24-49"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span> <span class="o">=</span> <span class="n">num</span>
<a id="__codelineno-24-50" name="__codelineno-24-50" href="#__codelineno-24-50"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-24-51" name="__codelineno-24-51" href="#__codelineno-24-51"></a>
<a id="__codelineno-24-52" name="__codelineno-24-52" href="#__codelineno-24-52"></a> <span class="k">def</span> <span class="nf">pop_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-53" name="__codelineno-24-53" href="#__codelineno-24-53"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首出队&quot;&quot;&quot;</span>
<a id="__codelineno-24-54" name="__codelineno-24-54" href="#__codelineno-24-54"></a> <span class="n">num</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">peek_first</span><span class="p">()</span>
<a id="__codelineno-24-55" name="__codelineno-24-55" href="#__codelineno-24-55"></a> <span class="c1"># 队首指针向后移动一位</span>
<a id="__codelineno-24-56" name="__codelineno-24-56" href="#__codelineno-24-56"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-24-57" name="__codelineno-24-57" href="#__codelineno-24-57"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-24-58" name="__codelineno-24-58" href="#__codelineno-24-58"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-24-59" name="__codelineno-24-59" href="#__codelineno-24-59"></a>
<a id="__codelineno-24-60" name="__codelineno-24-60" href="#__codelineno-24-60"></a> <span class="k">def</span> <span class="nf">pop_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-61" name="__codelineno-24-61" href="#__codelineno-24-61"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾出队&quot;&quot;&quot;</span>
<a id="__codelineno-24-62" name="__codelineno-24-62" href="#__codelineno-24-62"></a> <span class="n">num</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">peek_last</span><span class="p">()</span>
<a id="__codelineno-24-63" name="__codelineno-24-63" href="#__codelineno-24-63"></a> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-24-64" name="__codelineno-24-64" href="#__codelineno-24-64"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-24-65" name="__codelineno-24-65" href="#__codelineno-24-65"></a>
<a id="__codelineno-24-66" name="__codelineno-24-66" href="#__codelineno-24-66"></a> <span class="k">def</span> <span class="nf">peek_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-67" name="__codelineno-24-67" href="#__codelineno-24-67"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队首元素&quot;&quot;&quot;</span>
<a id="__codelineno-24-68" name="__codelineno-24-68" href="#__codelineno-24-68"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-24-69" name="__codelineno-24-69" href="#__codelineno-24-69"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-24-70" name="__codelineno-24-70" href="#__codelineno-24-70"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span><span class="p">]</span>
<a id="__codelineno-24-71" name="__codelineno-24-71" href="#__codelineno-24-71"></a>
<a id="__codelineno-24-72" name="__codelineno-24-72" href="#__codelineno-24-72"></a> <span class="k">def</span> <span class="nf">peek_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-24-73" name="__codelineno-24-73" href="#__codelineno-24-73"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队尾元素&quot;&quot;&quot;</span>
<a id="__codelineno-24-74" name="__codelineno-24-74" href="#__codelineno-24-74"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-24-75" name="__codelineno-24-75" href="#__codelineno-24-75"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-24-76" name="__codelineno-24-76" href="#__codelineno-24-76"></a> <span class="c1"># 计算尾元素索引</span>
<a id="__codelineno-24-77" name="__codelineno-24-77" href="#__codelineno-24-77"></a> <span class="n">last</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">_size</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-24-78" name="__codelineno-24-78" href="#__codelineno-24-78"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">[</span><span class="n">last</span><span class="p">]</span>
<a id="__codelineno-24-79" name="__codelineno-24-79" href="#__codelineno-24-79"></a>
<a id="__codelineno-24-80" name="__codelineno-24-80" href="#__codelineno-24-80"></a> <span class="k">def</span> <span class="nf">to_array</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]:</span>
<a id="__codelineno-24-81" name="__codelineno-24-81" href="#__codelineno-24-81"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;返回数组用于打印&quot;&quot;&quot;</span>
<a id="__codelineno-24-82" name="__codelineno-24-82" href="#__codelineno-24-82"></a> <span class="c1"># 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-24-83" name="__codelineno-24-83" href="#__codelineno-24-83"></a> <span class="n">res</span> <span class="o">=</span> <span class="p">[]</span>
<a id="__codelineno-24-84" name="__codelineno-24-84" href="#__codelineno-24-84"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_size</span><span class="p">):</span>
<a id="__codelineno-24-85" name="__codelineno-24-85" href="#__codelineno-24-85"></a> <span class="n">res</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">_front</span> <span class="o">+</span> <span class="n">i</span><span class="p">)])</span>
<a id="__codelineno-24-86" name="__codelineno-24-86" href="#__codelineno-24-86"></a> <span class="k">return</span> <span class="n">res</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.cpp</span><pre><span></span><code><a id="__codelineno-25-1" name="__codelineno-25-1" href="#__codelineno-25-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-25-2" name="__codelineno-25-2" href="#__codelineno-25-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-3" name="__codelineno-25-3" href="#__codelineno-25-3"></a><span class="w"> </span><span class="k">private</span><span class="o">:</span>
<a id="__codelineno-25-4" name="__codelineno-25-4" href="#__codelineno-25-4"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-25-5" name="__codelineno-25-5" href="#__codelineno-25-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-25-6" name="__codelineno-25-6" href="#__codelineno-25-6"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-25-7" name="__codelineno-25-7" href="#__codelineno-25-7"></a>
<a id="__codelineno-25-8" name="__codelineno-25-8" href="#__codelineno-25-8"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-25-9" name="__codelineno-25-9" href="#__codelineno-25-9"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-25-10" name="__codelineno-25-10" href="#__codelineno-25-10"></a><span class="w"> </span><span class="n">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-11" name="__codelineno-25-11" href="#__codelineno-25-11"></a><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">resize</span><span class="p">(</span><span class="n">capacity</span><span class="p">);</span>
<a id="__codelineno-25-12" name="__codelineno-25-12" href="#__codelineno-25-12"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-25-13" name="__codelineno-25-13" href="#__codelineno-25-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-14" name="__codelineno-25-14" href="#__codelineno-25-14"></a>
<a id="__codelineno-25-15" name="__codelineno-25-15" href="#__codelineno-25-15"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-25-16" name="__codelineno-25-16" href="#__codelineno-25-16"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-17" name="__codelineno-25-17" href="#__codelineno-25-17"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">size</span><span class="p">();</span>
<a id="__codelineno-25-18" name="__codelineno-25-18" href="#__codelineno-25-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-19" name="__codelineno-25-19" href="#__codelineno-25-19"></a>
<a id="__codelineno-25-20" name="__codelineno-25-20" href="#__codelineno-25-20"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-25-21" name="__codelineno-25-21" href="#__codelineno-25-21"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-22" name="__codelineno-25-22" href="#__codelineno-25-22"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-25-23" name="__codelineno-25-23" href="#__codelineno-25-23"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-24" name="__codelineno-25-24" href="#__codelineno-25-24"></a>
<a id="__codelineno-25-25" name="__codelineno-25-25" href="#__codelineno-25-25"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-25-26" name="__codelineno-25-26" href="#__codelineno-25-26"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-27" name="__codelineno-25-27" href="#__codelineno-25-27"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-25-28" name="__codelineno-25-28" href="#__codelineno-25-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-29" name="__codelineno-25-29" href="#__codelineno-25-29"></a>
<a id="__codelineno-25-30" name="__codelineno-25-30" href="#__codelineno-25-30"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-25-31" name="__codelineno-25-31" href="#__codelineno-25-31"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-32" name="__codelineno-25-32" href="#__codelineno-25-32"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-25-33" name="__codelineno-25-33" href="#__codelineno-25-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-25-34" name="__codelineno-25-34" href="#__codelineno-25-34"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-25-35" name="__codelineno-25-35" href="#__codelineno-25-35"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-25-36" name="__codelineno-25-36" href="#__codelineno-25-36"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-37" name="__codelineno-25-37" href="#__codelineno-25-37"></a>
<a id="__codelineno-25-38" name="__codelineno-25-38" href="#__codelineno-25-38"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-25-39" name="__codelineno-25-39" href="#__codelineno-25-39"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-40" name="__codelineno-25-40" href="#__codelineno-25-40"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-41" name="__codelineno-25-41" href="#__codelineno-25-41"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot;双向队列已满&quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-25-42" name="__codelineno-25-42" href="#__codelineno-25-42"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-25-43" name="__codelineno-25-43" href="#__codelineno-25-43"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-44" name="__codelineno-25-44" href="#__codelineno-25-44"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-25-45" name="__codelineno-25-45" href="#__codelineno-25-45"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-25-46" name="__codelineno-25-46" href="#__codelineno-25-46"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-25-47" name="__codelineno-25-47" href="#__codelineno-25-47"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-25-48" name="__codelineno-25-48" href="#__codelineno-25-48"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-25-49" name="__codelineno-25-49" href="#__codelineno-25-49"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-25-50" name="__codelineno-25-50" href="#__codelineno-25-50"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-51" name="__codelineno-25-51" href="#__codelineno-25-51"></a>
<a id="__codelineno-25-52" name="__codelineno-25-52" href="#__codelineno-25-52"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-25-53" name="__codelineno-25-53" href="#__codelineno-25-53"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-54" name="__codelineno-25-54" href="#__codelineno-25-54"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-55" name="__codelineno-25-55" href="#__codelineno-25-55"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot;双向队列已满&quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-25-56" name="__codelineno-25-56" href="#__codelineno-25-56"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-25-57" name="__codelineno-25-57" href="#__codelineno-25-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-58" name="__codelineno-25-58" href="#__codelineno-25-58"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-25-59" name="__codelineno-25-59" href="#__codelineno-25-59"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-25-60" name="__codelineno-25-60" href="#__codelineno-25-60"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-25-61" name="__codelineno-25-61" href="#__codelineno-25-61"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-25-62" name="__codelineno-25-62" href="#__codelineno-25-62"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-25-63" name="__codelineno-25-63" href="#__codelineno-25-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-64" name="__codelineno-25-64" href="#__codelineno-25-64"></a>
<a id="__codelineno-25-65" name="__codelineno-25-65" href="#__codelineno-25-65"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-25-66" name="__codelineno-25-66" href="#__codelineno-25-66"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-67" name="__codelineno-25-67" href="#__codelineno-25-67"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-25-68" name="__codelineno-25-68" href="#__codelineno-25-68"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-25-69" name="__codelineno-25-69" href="#__codelineno-25-69"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-25-70" name="__codelineno-25-70" href="#__codelineno-25-70"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-25-71" name="__codelineno-25-71" href="#__codelineno-25-71"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-25-72" name="__codelineno-25-72" href="#__codelineno-25-72"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-73" name="__codelineno-25-73" href="#__codelineno-25-73"></a>
<a id="__codelineno-25-74" name="__codelineno-25-74" href="#__codelineno-25-74"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-25-75" name="__codelineno-25-75" href="#__codelineno-25-75"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-76" name="__codelineno-25-76" href="#__codelineno-25-76"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-25-77" name="__codelineno-25-77" href="#__codelineno-25-77"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-25-78" name="__codelineno-25-78" href="#__codelineno-25-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-25-79" name="__codelineno-25-79" href="#__codelineno-25-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-80" name="__codelineno-25-80" href="#__codelineno-25-80"></a>
<a id="__codelineno-25-81" name="__codelineno-25-81" href="#__codelineno-25-81"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-25-82" name="__codelineno-25-82" href="#__codelineno-25-82"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-83" name="__codelineno-25-83" href="#__codelineno-25-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-25-84" name="__codelineno-25-84" href="#__codelineno-25-84"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-25-85" name="__codelineno-25-85" href="#__codelineno-25-85"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-25-86" name="__codelineno-25-86" href="#__codelineno-25-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-87" name="__codelineno-25-87" href="#__codelineno-25-87"></a>
<a id="__codelineno-25-88" name="__codelineno-25-88" href="#__codelineno-25-88"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-25-89" name="__codelineno-25-89" href="#__codelineno-25-89"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-90" name="__codelineno-25-90" href="#__codelineno-25-90"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-25-91" name="__codelineno-25-91" href="#__codelineno-25-91"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-25-92" name="__codelineno-25-92" href="#__codelineno-25-92"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-25-93" name="__codelineno-25-93" href="#__codelineno-25-93"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-25-94" name="__codelineno-25-94" href="#__codelineno-25-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-25-95" name="__codelineno-25-95" href="#__codelineno-25-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-96" name="__codelineno-25-96" href="#__codelineno-25-96"></a>
<a id="__codelineno-25-97" name="__codelineno-25-97" href="#__codelineno-25-97"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-25-98" name="__codelineno-25-98" href="#__codelineno-25-98"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">toVector</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-99" name="__codelineno-25-99" href="#__codelineno-25-99"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-25-100" name="__codelineno-25-100" href="#__codelineno-25-100"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">res</span><span class="p">(</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-25-101" name="__codelineno-25-101" href="#__codelineno-25-101"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-102" name="__codelineno-25-102" href="#__codelineno-25-102"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)];</span>
<a id="__codelineno-25-103" name="__codelineno-25-103" href="#__codelineno-25-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-104" name="__codelineno-25-104" href="#__codelineno-25-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-25-105" name="__codelineno-25-105" href="#__codelineno-25-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-106" name="__codelineno-25-106" href="#__codelineno-25-106"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.java</span><pre><span></span><code><a id="__codelineno-26-1" name="__codelineno-26-1" href="#__codelineno-26-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-26-2" name="__codelineno-26-2" href="#__codelineno-26-2"></a><span class="kd">class</span> <span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-3" name="__codelineno-26-3" href="#__codelineno-26-3"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-26-4" name="__codelineno-26-4" href="#__codelineno-26-4"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-26-5" name="__codelineno-26-5" href="#__codelineno-26-5"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-26-6" name="__codelineno-26-6" href="#__codelineno-26-6"></a>
<a id="__codelineno-26-7" name="__codelineno-26-7" href="#__codelineno-26-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-26-8" name="__codelineno-26-8" href="#__codelineno-26-8"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-9" name="__codelineno-26-9" href="#__codelineno-26-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="na">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-26-10" name="__codelineno-26-10" href="#__codelineno-26-10"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-11" name="__codelineno-26-11" href="#__codelineno-26-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-12" name="__codelineno-26-12" href="#__codelineno-26-12"></a>
<a id="__codelineno-26-13" name="__codelineno-26-13" href="#__codelineno-26-13"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-26-14" name="__codelineno-26-14" href="#__codelineno-26-14"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-15" name="__codelineno-26-15" href="#__codelineno-26-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="na">length</span><span class="p">;</span>
<a id="__codelineno-26-16" name="__codelineno-26-16" href="#__codelineno-26-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-17" name="__codelineno-26-17" href="#__codelineno-26-17"></a>
<a id="__codelineno-26-18" name="__codelineno-26-18" href="#__codelineno-26-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-26-19" name="__codelineno-26-19" href="#__codelineno-26-19"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-20" name="__codelineno-26-20" href="#__codelineno-26-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-26-21" name="__codelineno-26-21" href="#__codelineno-26-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-22" name="__codelineno-26-22" href="#__codelineno-26-22"></a>
<a id="__codelineno-26-23" name="__codelineno-26-23" href="#__codelineno-26-23"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-26-24" name="__codelineno-26-24" href="#__codelineno-26-24"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-25" name="__codelineno-26-25" href="#__codelineno-26-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-26" name="__codelineno-26-26" href="#__codelineno-26-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-27" name="__codelineno-26-27" href="#__codelineno-26-27"></a>
<a id="__codelineno-26-28" name="__codelineno-26-28" href="#__codelineno-26-28"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-26-29" name="__codelineno-26-29" href="#__codelineno-26-29"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-30" name="__codelineno-26-30" href="#__codelineno-26-30"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-26-31" name="__codelineno-26-31" href="#__codelineno-26-31"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-26-32" name="__codelineno-26-32" href="#__codelineno-26-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-26-33" name="__codelineno-26-33" href="#__codelineno-26-33"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-26-34" name="__codelineno-26-34" href="#__codelineno-26-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-35" name="__codelineno-26-35" href="#__codelineno-26-35"></a>
<a id="__codelineno-26-36" name="__codelineno-26-36" href="#__codelineno-26-36"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-26-37" name="__codelineno-26-37" href="#__codelineno-26-37"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-38" name="__codelineno-26-38" href="#__codelineno-26-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-39" name="__codelineno-26-39" href="#__codelineno-26-39"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-26-40" name="__codelineno-26-40" href="#__codelineno-26-40"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-26-41" name="__codelineno-26-41" href="#__codelineno-26-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-42" name="__codelineno-26-42" href="#__codelineno-26-42"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-26-43" name="__codelineno-26-43" href="#__codelineno-26-43"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-26-44" name="__codelineno-26-44" href="#__codelineno-26-44"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-45" name="__codelineno-26-45" href="#__codelineno-26-45"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-26-46" name="__codelineno-26-46" href="#__codelineno-26-46"></a><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">front</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-47" name="__codelineno-26-47" href="#__codelineno-26-47"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-26-48" name="__codelineno-26-48" href="#__codelineno-26-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-49" name="__codelineno-26-49" href="#__codelineno-26-49"></a>
<a id="__codelineno-26-50" name="__codelineno-26-50" href="#__codelineno-26-50"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-26-51" name="__codelineno-26-51" href="#__codelineno-26-51"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-52" name="__codelineno-26-52" href="#__codelineno-26-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-53" name="__codelineno-26-53" href="#__codelineno-26-53"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-26-54" name="__codelineno-26-54" href="#__codelineno-26-54"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-26-55" name="__codelineno-26-55" href="#__codelineno-26-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-56" name="__codelineno-26-56" href="#__codelineno-26-56"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-26-57" name="__codelineno-26-57" href="#__codelineno-26-57"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-26-58" name="__codelineno-26-58" href="#__codelineno-26-58"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-26-59" name="__codelineno-26-59" href="#__codelineno-26-59"></a><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">rear</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-60" name="__codelineno-26-60" href="#__codelineno-26-60"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-26-61" name="__codelineno-26-61" href="#__codelineno-26-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-62" name="__codelineno-26-62" href="#__codelineno-26-62"></a>
<a id="__codelineno-26-63" name="__codelineno-26-63" href="#__codelineno-26-63"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-26-64" name="__codelineno-26-64" href="#__codelineno-26-64"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-65" name="__codelineno-26-65" href="#__codelineno-26-65"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-26-66" name="__codelineno-26-66" href="#__codelineno-26-66"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-26-67" name="__codelineno-26-67" href="#__codelineno-26-67"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-68" name="__codelineno-26-68" href="#__codelineno-26-68"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-26-69" name="__codelineno-26-69" href="#__codelineno-26-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-70" name="__codelineno-26-70" href="#__codelineno-26-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-71" name="__codelineno-26-71" href="#__codelineno-26-71"></a>
<a id="__codelineno-26-72" name="__codelineno-26-72" href="#__codelineno-26-72"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-26-73" name="__codelineno-26-73" href="#__codelineno-26-73"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-74" name="__codelineno-26-74" href="#__codelineno-26-74"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-26-75" name="__codelineno-26-75" href="#__codelineno-26-75"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-26-76" name="__codelineno-26-76" href="#__codelineno-26-76"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-77" name="__codelineno-26-77" href="#__codelineno-26-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-78" name="__codelineno-26-78" href="#__codelineno-26-78"></a>
<a id="__codelineno-26-79" name="__codelineno-26-79" href="#__codelineno-26-79"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-26-80" name="__codelineno-26-80" href="#__codelineno-26-80"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-81" name="__codelineno-26-81" href="#__codelineno-26-81"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-26-82" name="__codelineno-26-82" href="#__codelineno-26-82"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-26-83" name="__codelineno-26-83" href="#__codelineno-26-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">front</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-26-84" name="__codelineno-26-84" href="#__codelineno-26-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-85" name="__codelineno-26-85" href="#__codelineno-26-85"></a>
<a id="__codelineno-26-86" name="__codelineno-26-86" href="#__codelineno-26-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-26-87" name="__codelineno-26-87" href="#__codelineno-26-87"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-88" name="__codelineno-26-88" href="#__codelineno-26-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-26-89" name="__codelineno-26-89" href="#__codelineno-26-89"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-26-90" name="__codelineno-26-90" href="#__codelineno-26-90"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-26-91" name="__codelineno-26-91" href="#__codelineno-26-91"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-92" name="__codelineno-26-92" href="#__codelineno-26-92"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">last</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-26-93" name="__codelineno-26-93" href="#__codelineno-26-93"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-94" name="__codelineno-26-94" href="#__codelineno-26-94"></a>
<a id="__codelineno-26-95" name="__codelineno-26-95" href="#__codelineno-26-95"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-26-96" name="__codelineno-26-96" href="#__codelineno-26-96"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="nf">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-97" name="__codelineno-26-97" href="#__codelineno-26-97"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-26-98" name="__codelineno-26-98" href="#__codelineno-26-98"></a><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="o">[</span><span class="n">queSize</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-26-99" name="__codelineno-26-99" href="#__codelineno-26-99"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-100" name="__codelineno-26-100" href="#__codelineno-26-100"></a><span class="w"> </span><span class="n">res</span><span class="o">[</span><span class="n">i</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-26-101" name="__codelineno-26-101" href="#__codelineno-26-101"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-102" name="__codelineno-26-102" href="#__codelineno-26-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-26-103" name="__codelineno-26-103" href="#__codelineno-26-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-104" name="__codelineno-26-104" href="#__codelineno-26-104"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.cs</span><pre><span></span><code><a id="__codelineno-27-1" name="__codelineno-27-1" href="#__codelineno-27-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-27-2" name="__codelineno-27-2" href="#__codelineno-27-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-3" name="__codelineno-27-3" href="#__codelineno-27-3"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="k">readonly</span><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-27-4" name="__codelineno-27-4" href="#__codelineno-27-4"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-27-5" name="__codelineno-27-5" href="#__codelineno-27-5"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-27-6" name="__codelineno-27-6" href="#__codelineno-27-6"></a>
<a id="__codelineno-27-7" name="__codelineno-27-7" href="#__codelineno-27-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-27-8" name="__codelineno-27-8" href="#__codelineno-27-8"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-9" name="__codelineno-27-9" href="#__codelineno-27-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="p">[</span><span class="n">capacity</span><span class="p">];</span>
<a id="__codelineno-27-10" name="__codelineno-27-10" href="#__codelineno-27-10"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-27-11" name="__codelineno-27-11" href="#__codelineno-27-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-12" name="__codelineno-27-12" href="#__codelineno-27-12"></a>
<a id="__codelineno-27-13" name="__codelineno-27-13" href="#__codelineno-27-13"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-27-14" name="__codelineno-27-14" href="#__codelineno-27-14"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">Capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-15" name="__codelineno-27-15" href="#__codelineno-27-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">Length</span><span class="p">;</span>
<a id="__codelineno-27-16" name="__codelineno-27-16" href="#__codelineno-27-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-17" name="__codelineno-27-17" href="#__codelineno-27-17"></a>
<a id="__codelineno-27-18" name="__codelineno-27-18" href="#__codelineno-27-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-27-19" name="__codelineno-27-19" href="#__codelineno-27-19"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">Size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-20" name="__codelineno-27-20" href="#__codelineno-27-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-27-21" name="__codelineno-27-21" href="#__codelineno-27-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-22" name="__codelineno-27-22" href="#__codelineno-27-22"></a>
<a id="__codelineno-27-23" name="__codelineno-27-23" href="#__codelineno-27-23"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-27-24" name="__codelineno-27-24" href="#__codelineno-27-24"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="nf">IsEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-25" name="__codelineno-27-25" href="#__codelineno-27-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-27-26" name="__codelineno-27-26" href="#__codelineno-27-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-27" name="__codelineno-27-27" href="#__codelineno-27-27"></a>
<a id="__codelineno-27-28" name="__codelineno-27-28" href="#__codelineno-27-28"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-27-29" name="__codelineno-27-29" href="#__codelineno-27-29"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">Index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-30" name="__codelineno-27-30" href="#__codelineno-27-30"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-27-31" name="__codelineno-27-31" href="#__codelineno-27-31"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-27-32" name="__codelineno-27-32" href="#__codelineno-27-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-27-33" name="__codelineno-27-33" href="#__codelineno-27-33"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">Capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">Capacity</span><span class="p">();</span>
<a id="__codelineno-27-34" name="__codelineno-27-34" href="#__codelineno-27-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-35" name="__codelineno-27-35" href="#__codelineno-27-35"></a>
<a id="__codelineno-27-36" name="__codelineno-27-36" href="#__codelineno-27-36"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-27-37" name="__codelineno-27-37" href="#__codelineno-27-37"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">PushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-38" name="__codelineno-27-38" href="#__codelineno-27-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">Capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-39" name="__codelineno-27-39" href="#__codelineno-27-39"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-27-40" name="__codelineno-27-40" href="#__codelineno-27-40"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-27-41" name="__codelineno-27-41" href="#__codelineno-27-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-42" name="__codelineno-27-42" href="#__codelineno-27-42"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-27-43" name="__codelineno-27-43" href="#__codelineno-27-43"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-27-44" name="__codelineno-27-44" href="#__codelineno-27-44"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-45" name="__codelineno-27-45" href="#__codelineno-27-45"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-27-46" name="__codelineno-27-46" href="#__codelineno-27-46"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-47" name="__codelineno-27-47" href="#__codelineno-27-47"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-27-48" name="__codelineno-27-48" href="#__codelineno-27-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-49" name="__codelineno-27-49" href="#__codelineno-27-49"></a>
<a id="__codelineno-27-50" name="__codelineno-27-50" href="#__codelineno-27-50"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-27-51" name="__codelineno-27-51" href="#__codelineno-27-51"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">PushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-52" name="__codelineno-27-52" href="#__codelineno-27-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">Capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-53" name="__codelineno-27-53" href="#__codelineno-27-53"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-27-54" name="__codelineno-27-54" href="#__codelineno-27-54"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-27-55" name="__codelineno-27-55" href="#__codelineno-27-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-56" name="__codelineno-27-56" href="#__codelineno-27-56"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-27-57" name="__codelineno-27-57" href="#__codelineno-27-57"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-27-58" name="__codelineno-27-58" href="#__codelineno-27-58"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-27-59" name="__codelineno-27-59" href="#__codelineno-27-59"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-60" name="__codelineno-27-60" href="#__codelineno-27-60"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-27-61" name="__codelineno-27-61" href="#__codelineno-27-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-62" name="__codelineno-27-62" href="#__codelineno-27-62"></a>
<a id="__codelineno-27-63" name="__codelineno-27-63" href="#__codelineno-27-63"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-27-64" name="__codelineno-27-64" href="#__codelineno-27-64"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">PopFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-65" name="__codelineno-27-65" href="#__codelineno-27-65"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">PeekFirst</span><span class="p">();</span>
<a id="__codelineno-27-66" name="__codelineno-27-66" href="#__codelineno-27-66"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-27-67" name="__codelineno-27-67" href="#__codelineno-27-67"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-68" name="__codelineno-27-68" href="#__codelineno-27-68"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-27-69" name="__codelineno-27-69" href="#__codelineno-27-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-70" name="__codelineno-27-70" href="#__codelineno-27-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-71" name="__codelineno-27-71" href="#__codelineno-27-71"></a>
<a id="__codelineno-27-72" name="__codelineno-27-72" href="#__codelineno-27-72"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-27-73" name="__codelineno-27-73" href="#__codelineno-27-73"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">PopLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-74" name="__codelineno-27-74" href="#__codelineno-27-74"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">PeekLast</span><span class="p">();</span>
<a id="__codelineno-27-75" name="__codelineno-27-75" href="#__codelineno-27-75"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-27-76" name="__codelineno-27-76" href="#__codelineno-27-76"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-77" name="__codelineno-27-77" href="#__codelineno-27-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-78" name="__codelineno-27-78" href="#__codelineno-27-78"></a>
<a id="__codelineno-27-79" name="__codelineno-27-79" href="#__codelineno-27-79"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-27-80" name="__codelineno-27-80" href="#__codelineno-27-80"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">PeekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-81" name="__codelineno-27-81" href="#__codelineno-27-81"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-82" name="__codelineno-27-82" href="#__codelineno-27-82"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">InvalidOperationException</span><span class="p">();</span>
<a id="__codelineno-27-83" name="__codelineno-27-83" href="#__codelineno-27-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-84" name="__codelineno-27-84" href="#__codelineno-27-84"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-27-85" name="__codelineno-27-85" href="#__codelineno-27-85"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-86" name="__codelineno-27-86" href="#__codelineno-27-86"></a>
<a id="__codelineno-27-87" name="__codelineno-27-87" href="#__codelineno-27-87"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-27-88" name="__codelineno-27-88" href="#__codelineno-27-88"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">PeekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-89" name="__codelineno-27-89" href="#__codelineno-27-89"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">IsEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-90" name="__codelineno-27-90" href="#__codelineno-27-90"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">InvalidOperationException</span><span class="p">();</span>
<a id="__codelineno-27-91" name="__codelineno-27-91" href="#__codelineno-27-91"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-92" name="__codelineno-27-92" href="#__codelineno-27-92"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-27-93" name="__codelineno-27-93" href="#__codelineno-27-93"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-94" name="__codelineno-27-94" href="#__codelineno-27-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-27-95" name="__codelineno-27-95" href="#__codelineno-27-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-96" name="__codelineno-27-96" href="#__codelineno-27-96"></a>
<a id="__codelineno-27-97" name="__codelineno-27-97" href="#__codelineno-27-97"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-27-98" name="__codelineno-27-98" href="#__codelineno-27-98"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="nf">ToArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-99" name="__codelineno-27-99" href="#__codelineno-27-99"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-27-100" name="__codelineno-27-100" href="#__codelineno-27-100"></a><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="p">[</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-27-101" name="__codelineno-27-101" href="#__codelineno-27-101"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-102" name="__codelineno-27-102" href="#__codelineno-27-102"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">Index</span><span class="p">(</span><span class="n">j</span><span class="p">)];</span>
<a id="__codelineno-27-103" name="__codelineno-27-103" href="#__codelineno-27-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-104" name="__codelineno-27-104" href="#__codelineno-27-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-27-105" name="__codelineno-27-105" href="#__codelineno-27-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-106" name="__codelineno-27-106" href="#__codelineno-27-106"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.go</span><pre><span></span><code><a id="__codelineno-28-1" name="__codelineno-28-1" href="#__codelineno-28-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-28-2" name="__codelineno-28-2" href="#__codelineno-28-2"></a><span class="kd">type</span><span class="w"> </span><span class="nx">arrayDeque</span><span class="w"> </span><span class="kd">struct</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-3" name="__codelineno-28-3" href="#__codelineno-28-3"></a><span class="w"> </span><span class="nx">nums</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-28-4" name="__codelineno-28-4" href="#__codelineno-28-4"></a><span class="w"> </span><span class="nx">front</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-28-5" name="__codelineno-28-5" href="#__codelineno-28-5"></a><span class="w"> </span><span class="nx">queSize</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-28-6" name="__codelineno-28-6" href="#__codelineno-28-6"></a><span class="w"> </span><span class="nx">queCapacity</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 队列容量(即最大容纳元素数量)</span>
<a id="__codelineno-28-7" name="__codelineno-28-7" href="#__codelineno-28-7"></a><span class="p">}</span>
<a id="__codelineno-28-8" name="__codelineno-28-8" href="#__codelineno-28-8"></a>
<a id="__codelineno-28-9" name="__codelineno-28-9" href="#__codelineno-28-9"></a><span class="cm">/* 初始化队列 */</span>
<a id="__codelineno-28-10" name="__codelineno-28-10" href="#__codelineno-28-10"></a><span class="kd">func</span><span class="w"> </span><span class="nx">newArrayDeque</span><span class="p">(</span><span class="nx">queCapacity</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-11" name="__codelineno-28-11" href="#__codelineno-28-11"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">&amp;</span><span class="nx">arrayDeque</span><span class="p">{</span>
<a id="__codelineno-28-12" name="__codelineno-28-12" href="#__codelineno-28-12"></a><span class="w"> </span><span class="nx">nums</span><span class="p">:</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">queCapacity</span><span class="p">),</span>
<a id="__codelineno-28-13" name="__codelineno-28-13" href="#__codelineno-28-13"></a><span class="w"> </span><span class="nx">queCapacity</span><span class="p">:</span><span class="w"> </span><span class="nx">queCapacity</span><span class="p">,</span>
<a id="__codelineno-28-14" name="__codelineno-28-14" href="#__codelineno-28-14"></a><span class="w"> </span><span class="nx">front</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-28-15" name="__codelineno-28-15" href="#__codelineno-28-15"></a><span class="w"> </span><span class="nx">queSize</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-28-16" name="__codelineno-28-16" href="#__codelineno-28-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-17" name="__codelineno-28-17" href="#__codelineno-28-17"></a><span class="p">}</span>
<a id="__codelineno-28-18" name="__codelineno-28-18" href="#__codelineno-28-18"></a>
<a id="__codelineno-28-19" name="__codelineno-28-19" href="#__codelineno-28-19"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-28-20" name="__codelineno-28-20" href="#__codelineno-28-20"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-21" name="__codelineno-28-21" href="#__codelineno-28-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span>
<a id="__codelineno-28-22" name="__codelineno-28-22" href="#__codelineno-28-22"></a><span class="p">}</span>
<a id="__codelineno-28-23" name="__codelineno-28-23" href="#__codelineno-28-23"></a>
<a id="__codelineno-28-24" name="__codelineno-28-24" href="#__codelineno-28-24"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-28-25" name="__codelineno-28-25" href="#__codelineno-28-25"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-26" name="__codelineno-28-26" href="#__codelineno-28-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
<a id="__codelineno-28-27" name="__codelineno-28-27" href="#__codelineno-28-27"></a><span class="p">}</span>
<a id="__codelineno-28-28" name="__codelineno-28-28" href="#__codelineno-28-28"></a>
<a id="__codelineno-28-29" name="__codelineno-28-29" href="#__codelineno-28-29"></a><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-28-30" name="__codelineno-28-30" href="#__codelineno-28-30"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-31" name="__codelineno-28-31" href="#__codelineno-28-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-28-32" name="__codelineno-28-32" href="#__codelineno-28-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-28-33" name="__codelineno-28-33" href="#__codelineno-28-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-28-34" name="__codelineno-28-34" href="#__codelineno-28-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="p">)</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span>
<a id="__codelineno-28-35" name="__codelineno-28-35" href="#__codelineno-28-35"></a><span class="p">}</span>
<a id="__codelineno-28-36" name="__codelineno-28-36" href="#__codelineno-28-36"></a>
<a id="__codelineno-28-37" name="__codelineno-28-37" href="#__codelineno-28-37"></a><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-28-38" name="__codelineno-28-38" href="#__codelineno-28-38"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-39" name="__codelineno-28-39" href="#__codelineno-28-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-40" name="__codelineno-28-40" href="#__codelineno-28-40"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-28-41" name="__codelineno-28-41" href="#__codelineno-28-41"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-28-42" name="__codelineno-28-42" href="#__codelineno-28-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-43" name="__codelineno-28-43" href="#__codelineno-28-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-28-44" name="__codelineno-28-44" href="#__codelineno-28-44"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-28-45" name="__codelineno-28-45" href="#__codelineno-28-45"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-46" name="__codelineno-28-46" href="#__codelineno-28-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-28-47" name="__codelineno-28-47" href="#__codelineno-28-47"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-28-48" name="__codelineno-28-48" href="#__codelineno-28-48"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span>
<a id="__codelineno-28-49" name="__codelineno-28-49" href="#__codelineno-28-49"></a><span class="p">}</span>
<a id="__codelineno-28-50" name="__codelineno-28-50" href="#__codelineno-28-50"></a>
<a id="__codelineno-28-51" name="__codelineno-28-51" href="#__codelineno-28-51"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-28-52" name="__codelineno-28-52" href="#__codelineno-28-52"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-53" name="__codelineno-28-53" href="#__codelineno-28-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-54" name="__codelineno-28-54" href="#__codelineno-28-54"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-28-55" name="__codelineno-28-55" href="#__codelineno-28-55"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-28-56" name="__codelineno-28-56" href="#__codelineno-28-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-57" name="__codelineno-28-57" href="#__codelineno-28-57"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-28-58" name="__codelineno-28-58" href="#__codelineno-28-58"></a><span class="w"> </span><span class="nx">rear</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">)</span>
<a id="__codelineno-28-59" name="__codelineno-28-59" href="#__codelineno-28-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-28-60" name="__codelineno-28-60" href="#__codelineno-28-60"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-28-61" name="__codelineno-28-61" href="#__codelineno-28-61"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span>
<a id="__codelineno-28-62" name="__codelineno-28-62" href="#__codelineno-28-62"></a><span class="p">}</span>
<a id="__codelineno-28-63" name="__codelineno-28-63" href="#__codelineno-28-63"></a>
<a id="__codelineno-28-64" name="__codelineno-28-64" href="#__codelineno-28-64"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-28-65" name="__codelineno-28-65" href="#__codelineno-28-65"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-66" name="__codelineno-28-66" href="#__codelineno-28-66"></a><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">()</span>
<a id="__codelineno-28-67" name="__codelineno-28-67" href="#__codelineno-28-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-28-68" name="__codelineno-28-68" href="#__codelineno-28-68"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-69" name="__codelineno-28-69" href="#__codelineno-28-69"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span>
<a id="__codelineno-28-70" name="__codelineno-28-70" href="#__codelineno-28-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-28-71" name="__codelineno-28-71" href="#__codelineno-28-71"></a><span class="p">}</span>
<a id="__codelineno-28-72" name="__codelineno-28-72" href="#__codelineno-28-72"></a>
<a id="__codelineno-28-73" name="__codelineno-28-73" href="#__codelineno-28-73"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-28-74" name="__codelineno-28-74" href="#__codelineno-28-74"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-75" name="__codelineno-28-75" href="#__codelineno-28-75"></a><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">()</span>
<a id="__codelineno-28-76" name="__codelineno-28-76" href="#__codelineno-28-76"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span>
<a id="__codelineno-28-77" name="__codelineno-28-77" href="#__codelineno-28-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-28-78" name="__codelineno-28-78" href="#__codelineno-28-78"></a><span class="p">}</span>
<a id="__codelineno-28-79" name="__codelineno-28-79" href="#__codelineno-28-79"></a>
<a id="__codelineno-28-80" name="__codelineno-28-80" href="#__codelineno-28-80"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-28-81" name="__codelineno-28-81" href="#__codelineno-28-81"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-82" name="__codelineno-28-82" href="#__codelineno-28-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-83" name="__codelineno-28-83" href="#__codelineno-28-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-28-84" name="__codelineno-28-84" href="#__codelineno-28-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-85" name="__codelineno-28-85" href="#__codelineno-28-85"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span>
<a id="__codelineno-28-86" name="__codelineno-28-86" href="#__codelineno-28-86"></a><span class="p">}</span>
<a id="__codelineno-28-87" name="__codelineno-28-87" href="#__codelineno-28-87"></a>
<a id="__codelineno-28-88" name="__codelineno-28-88" href="#__codelineno-28-88"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-28-89" name="__codelineno-28-89" href="#__codelineno-28-89"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-90" name="__codelineno-28-90" href="#__codelineno-28-90"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-91" name="__codelineno-28-91" href="#__codelineno-28-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-28-92" name="__codelineno-28-92" href="#__codelineno-28-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-93" name="__codelineno-28-93" href="#__codelineno-28-93"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-28-94" name="__codelineno-28-94" href="#__codelineno-28-94"></a><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-95" name="__codelineno-28-95" href="#__codelineno-28-95"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">]</span>
<a id="__codelineno-28-96" name="__codelineno-28-96" href="#__codelineno-28-96"></a><span class="p">}</span>
<a id="__codelineno-28-97" name="__codelineno-28-97" href="#__codelineno-28-97"></a>
<a id="__codelineno-28-98" name="__codelineno-28-98" href="#__codelineno-28-98"></a><span class="cm">/* 获取 Slice 用于打印 */</span>
<a id="__codelineno-28-99" name="__codelineno-28-99" href="#__codelineno-28-99"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">toSlice</span><span class="p">()</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-100" name="__codelineno-28-100" href="#__codelineno-28-100"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-28-101" name="__codelineno-28-101" href="#__codelineno-28-101"></a><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">)</span>
<a id="__codelineno-28-102" name="__codelineno-28-102" href="#__codelineno-28-102"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-28-103" name="__codelineno-28-103" href="#__codelineno-28-103"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)]</span>
<a id="__codelineno-28-104" name="__codelineno-28-104" href="#__codelineno-28-104"></a><span class="w"> </span><span class="nx">j</span><span class="o">++</span>
<a id="__codelineno-28-105" name="__codelineno-28-105" href="#__codelineno-28-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-28-106" name="__codelineno-28-106" href="#__codelineno-28-106"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span>
<a id="__codelineno-28-107" name="__codelineno-28-107" href="#__codelineno-28-107"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.swift</span><pre><span></span><code><a id="__codelineno-29-1" name="__codelineno-29-1" href="#__codelineno-29-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-29-2" name="__codelineno-29-2" href="#__codelineno-29-2"></a><span class="kd">class</span> <span class="nc">ArrayDeque</span> <span class="p">{</span>
<a id="__codelineno-29-3" name="__codelineno-29-3" href="#__codelineno-29-3"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">nums</span><span class="p">:</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-29-4" name="__codelineno-29-4" href="#__codelineno-29-4"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">front</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-29-5" name="__codelineno-29-5" href="#__codelineno-29-5"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">queSize</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 双向队列长度</span>
<a id="__codelineno-29-6" name="__codelineno-29-6" href="#__codelineno-29-6"></a>
<a id="__codelineno-29-7" name="__codelineno-29-7" href="#__codelineno-29-7"></a> <span class="cm">/* 构造方法 */</span>
<a id="__codelineno-29-8" name="__codelineno-29-8" href="#__codelineno-29-8"></a> <span class="kd">init</span><span class="p">(</span><span class="n">capacity</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-29-9" name="__codelineno-29-9" href="#__codelineno-29-9"></a> <span class="n">nums</span> <span class="p">=</span> <span class="nb">Array</span><span class="p">(</span><span class="n">repeating</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="bp">count</span><span class="p">:</span> <span class="n">capacity</span><span class="p">)</span>
<a id="__codelineno-29-10" name="__codelineno-29-10" href="#__codelineno-29-10"></a> <span class="n">front</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-29-11" name="__codelineno-29-11" href="#__codelineno-29-11"></a> <span class="n">queSize</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-29-12" name="__codelineno-29-12" href="#__codelineno-29-12"></a> <span class="p">}</span>
<a id="__codelineno-29-13" name="__codelineno-29-13" href="#__codelineno-29-13"></a>
<a id="__codelineno-29-14" name="__codelineno-29-14" href="#__codelineno-29-14"></a> <span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-29-15" name="__codelineno-29-15" href="#__codelineno-29-15"></a> <span class="kd">func</span> <span class="nf">capacity</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-16" name="__codelineno-29-16" href="#__codelineno-29-16"></a> <span class="n">nums</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-29-17" name="__codelineno-29-17" href="#__codelineno-29-17"></a> <span class="p">}</span>
<a id="__codelineno-29-18" name="__codelineno-29-18" href="#__codelineno-29-18"></a>
<a id="__codelineno-29-19" name="__codelineno-29-19" href="#__codelineno-29-19"></a> <span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-29-20" name="__codelineno-29-20" href="#__codelineno-29-20"></a> <span class="kd">func</span> <span class="nf">size</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-21" name="__codelineno-29-21" href="#__codelineno-29-21"></a> <span class="n">queSize</span>
<a id="__codelineno-29-22" name="__codelineno-29-22" href="#__codelineno-29-22"></a> <span class="p">}</span>
<a id="__codelineno-29-23" name="__codelineno-29-23" href="#__codelineno-29-23"></a>
<a id="__codelineno-29-24" name="__codelineno-29-24" href="#__codelineno-29-24"></a> <span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-29-25" name="__codelineno-29-25" href="#__codelineno-29-25"></a> <span class="kd">func</span> <span class="nf">isEmpty</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Bool</span> <span class="p">{</span>
<a id="__codelineno-29-26" name="__codelineno-29-26" href="#__codelineno-29-26"></a> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="mi">0</span>
<a id="__codelineno-29-27" name="__codelineno-29-27" href="#__codelineno-29-27"></a> <span class="p">}</span>
<a id="__codelineno-29-28" name="__codelineno-29-28" href="#__codelineno-29-28"></a>
<a id="__codelineno-29-29" name="__codelineno-29-29" href="#__codelineno-29-29"></a> <span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-29-30" name="__codelineno-29-30" href="#__codelineno-29-30"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-31" name="__codelineno-29-31" href="#__codelineno-29-31"></a> <span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-29-32" name="__codelineno-29-32" href="#__codelineno-29-32"></a> <span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-29-33" name="__codelineno-29-33" href="#__codelineno-29-33"></a> <span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-29-34" name="__codelineno-29-34" href="#__codelineno-29-34"></a> <span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="n">capacity</span><span class="p">())</span> <span class="o">%</span> <span class="n">capacity</span><span class="p">()</span>
<a id="__codelineno-29-35" name="__codelineno-29-35" href="#__codelineno-29-35"></a> <span class="p">}</span>
<a id="__codelineno-29-36" name="__codelineno-29-36" href="#__codelineno-29-36"></a>
<a id="__codelineno-29-37" name="__codelineno-29-37" href="#__codelineno-29-37"></a> <span class="cm">/* 队首入队 */</span>
<a id="__codelineno-29-38" name="__codelineno-29-38" href="#__codelineno-29-38"></a> <span class="kd">func</span> <span class="nf">pushFirst</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-29-39" name="__codelineno-29-39" href="#__codelineno-29-39"></a> <span class="k">if</span> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="n">capacity</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-29-40" name="__codelineno-29-40" href="#__codelineno-29-40"></a> <span class="bp">print</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-29-41" name="__codelineno-29-41" href="#__codelineno-29-41"></a> <span class="k">return</span>
<a id="__codelineno-29-42" name="__codelineno-29-42" href="#__codelineno-29-42"></a> <span class="p">}</span>
<a id="__codelineno-29-43" name="__codelineno-29-43" href="#__codelineno-29-43"></a> <span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-29-44" name="__codelineno-29-44" href="#__codelineno-29-44"></a> <span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-29-45" name="__codelineno-29-45" href="#__codelineno-29-45"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-29-46" name="__codelineno-29-46" href="#__codelineno-29-46"></a> <span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-29-47" name="__codelineno-29-47" href="#__codelineno-29-47"></a> <span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span> <span class="p">=</span> <span class="n">num</span>
<a id="__codelineno-29-48" name="__codelineno-29-48" href="#__codelineno-29-48"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-29-49" name="__codelineno-29-49" href="#__codelineno-29-49"></a> <span class="p">}</span>
<a id="__codelineno-29-50" name="__codelineno-29-50" href="#__codelineno-29-50"></a>
<a id="__codelineno-29-51" name="__codelineno-29-51" href="#__codelineno-29-51"></a> <span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-29-52" name="__codelineno-29-52" href="#__codelineno-29-52"></a> <span class="kd">func</span> <span class="nf">pushLast</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-29-53" name="__codelineno-29-53" href="#__codelineno-29-53"></a> <span class="k">if</span> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="n">capacity</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-29-54" name="__codelineno-29-54" href="#__codelineno-29-54"></a> <span class="bp">print</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-29-55" name="__codelineno-29-55" href="#__codelineno-29-55"></a> <span class="k">return</span>
<a id="__codelineno-29-56" name="__codelineno-29-56" href="#__codelineno-29-56"></a> <span class="p">}</span>
<a id="__codelineno-29-57" name="__codelineno-29-57" href="#__codelineno-29-57"></a> <span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-29-58" name="__codelineno-29-58" href="#__codelineno-29-58"></a> <span class="kd">let</span> <span class="nv">rear</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="n">size</span><span class="p">())</span>
<a id="__codelineno-29-59" name="__codelineno-29-59" href="#__codelineno-29-59"></a> <span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-29-60" name="__codelineno-29-60" href="#__codelineno-29-60"></a> <span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span> <span class="p">=</span> <span class="n">num</span>
<a id="__codelineno-29-61" name="__codelineno-29-61" href="#__codelineno-29-61"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-29-62" name="__codelineno-29-62" href="#__codelineno-29-62"></a> <span class="p">}</span>
<a id="__codelineno-29-63" name="__codelineno-29-63" href="#__codelineno-29-63"></a>
<a id="__codelineno-29-64" name="__codelineno-29-64" href="#__codelineno-29-64"></a> <span class="cm">/* 队首出队 */</span>
<a id="__codelineno-29-65" name="__codelineno-29-65" href="#__codelineno-29-65"></a> <span class="kd">func</span> <span class="nf">popFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-66" name="__codelineno-29-66" href="#__codelineno-29-66"></a> <span class="kd">let</span> <span class="nv">num</span> <span class="p">=</span> <span class="n">peekFirst</span><span class="p">()</span>
<a id="__codelineno-29-67" name="__codelineno-29-67" href="#__codelineno-29-67"></a> <span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-29-68" name="__codelineno-29-68" href="#__codelineno-29-68"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-29-69" name="__codelineno-29-69" href="#__codelineno-29-69"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-29-70" name="__codelineno-29-70" href="#__codelineno-29-70"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-29-71" name="__codelineno-29-71" href="#__codelineno-29-71"></a> <span class="p">}</span>
<a id="__codelineno-29-72" name="__codelineno-29-72" href="#__codelineno-29-72"></a>
<a id="__codelineno-29-73" name="__codelineno-29-73" href="#__codelineno-29-73"></a> <span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-29-74" name="__codelineno-29-74" href="#__codelineno-29-74"></a> <span class="kd">func</span> <span class="nf">popLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-75" name="__codelineno-29-75" href="#__codelineno-29-75"></a> <span class="kd">let</span> <span class="nv">num</span> <span class="p">=</span> <span class="n">peekLast</span><span class="p">()</span>
<a id="__codelineno-29-76" name="__codelineno-29-76" href="#__codelineno-29-76"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-29-77" name="__codelineno-29-77" href="#__codelineno-29-77"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-29-78" name="__codelineno-29-78" href="#__codelineno-29-78"></a> <span class="p">}</span>
<a id="__codelineno-29-79" name="__codelineno-29-79" href="#__codelineno-29-79"></a>
<a id="__codelineno-29-80" name="__codelineno-29-80" href="#__codelineno-29-80"></a> <span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-29-81" name="__codelineno-29-81" href="#__codelineno-29-81"></a> <span class="kd">func</span> <span class="nf">peekFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-82" name="__codelineno-29-82" href="#__codelineno-29-82"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-29-83" name="__codelineno-29-83" href="#__codelineno-29-83"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-29-84" name="__codelineno-29-84" href="#__codelineno-29-84"></a> <span class="p">}</span>
<a id="__codelineno-29-85" name="__codelineno-29-85" href="#__codelineno-29-85"></a> <span class="k">return</span> <span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span>
<a id="__codelineno-29-86" name="__codelineno-29-86" href="#__codelineno-29-86"></a> <span class="p">}</span>
<a id="__codelineno-29-87" name="__codelineno-29-87" href="#__codelineno-29-87"></a>
<a id="__codelineno-29-88" name="__codelineno-29-88" href="#__codelineno-29-88"></a> <span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-29-89" name="__codelineno-29-89" href="#__codelineno-29-89"></a> <span class="kd">func</span> <span class="nf">peekLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-29-90" name="__codelineno-29-90" href="#__codelineno-29-90"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-29-91" name="__codelineno-29-91" href="#__codelineno-29-91"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-29-92" name="__codelineno-29-92" href="#__codelineno-29-92"></a> <span class="p">}</span>
<a id="__codelineno-29-93" name="__codelineno-29-93" href="#__codelineno-29-93"></a> <span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-29-94" name="__codelineno-29-94" href="#__codelineno-29-94"></a> <span class="kd">let</span> <span class="nv">last</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="n">size</span><span class="p">()</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-29-95" name="__codelineno-29-95" href="#__codelineno-29-95"></a> <span class="k">return</span> <span class="n">nums</span><span class="p">[</span><span class="bp">last</span><span class="p">]</span>
<a id="__codelineno-29-96" name="__codelineno-29-96" href="#__codelineno-29-96"></a> <span class="p">}</span>
<a id="__codelineno-29-97" name="__codelineno-29-97" href="#__codelineno-29-97"></a>
<a id="__codelineno-29-98" name="__codelineno-29-98" href="#__codelineno-29-98"></a> <span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-29-99" name="__codelineno-29-99" href="#__codelineno-29-99"></a> <span class="kd">func</span> <span class="nf">toArray</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-29-100" name="__codelineno-29-100" href="#__codelineno-29-100"></a> <span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-29-101" name="__codelineno-29-101" href="#__codelineno-29-101"></a> <span class="kd">var</span> <span class="nv">res</span> <span class="p">=</span> <span class="nb">Array</span><span class="p">(</span><span class="n">repeating</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="bp">count</span><span class="p">:</span> <span class="n">size</span><span class="p">())</span>
<a id="__codelineno-29-102" name="__codelineno-29-102" href="#__codelineno-29-102"></a> <span class="k">for</span> <span class="p">(</span><span class="n">i</span><span class="p">,</span> <span class="n">j</span><span class="p">)</span> <span class="k">in</span> <span class="n">sequence</span><span class="p">(</span><span class="bp">first</span><span class="p">:</span> <span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">front</span><span class="p">),</span> <span class="n">next</span><span class="p">:</span> <span class="p">{</span> <span class="nv">$0</span> <span class="o">&lt;</span> <span class="kc">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span> <span class="o">-</span> <span class="mi">1</span> <span class="p">?</span> <span class="p">(</span><span class="nv">$0</span> <span class="o">+</span> <span class="mi">1</span><span class="p">,</span> <span class="nv">$1</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span> <span class="p">:</span> <span class="kc">nil</span> <span class="p">})</span> <span class="p">{</span>
<a id="__codelineno-29-103" name="__codelineno-29-103" href="#__codelineno-29-103"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="p">=</span> <span class="n">nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">j</span><span class="p">)]</span>
<a id="__codelineno-29-104" name="__codelineno-29-104" href="#__codelineno-29-104"></a> <span class="p">}</span>
<a id="__codelineno-29-105" name="__codelineno-29-105" href="#__codelineno-29-105"></a> <span class="k">return</span> <span class="n">res</span>
<a id="__codelineno-29-106" name="__codelineno-29-106" href="#__codelineno-29-106"></a> <span class="p">}</span>
<a id="__codelineno-29-107" name="__codelineno-29-107" href="#__codelineno-29-107"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.js</span><pre><span></span><code><a id="__codelineno-30-1" name="__codelineno-30-1" href="#__codelineno-30-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-30-2" name="__codelineno-30-2" href="#__codelineno-30-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-3" name="__codelineno-30-3" href="#__codelineno-30-3"></a><span class="w"> </span><span class="err">#</span><span class="nx">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-30-4" name="__codelineno-30-4" href="#__codelineno-30-4"></a><span class="w"> </span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-30-5" name="__codelineno-30-5" href="#__codelineno-30-5"></a><span class="w"> </span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-30-6" name="__codelineno-30-6" href="#__codelineno-30-6"></a>
<a id="__codelineno-30-7" name="__codelineno-30-7" href="#__codelineno-30-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-30-8" name="__codelineno-30-8" href="#__codelineno-30-8"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-9" name="__codelineno-30-9" href="#__codelineno-30-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">capacity</span><span class="p">);</span>
<a id="__codelineno-30-10" name="__codelineno-30-10" href="#__codelineno-30-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-30-11" name="__codelineno-30-11" href="#__codelineno-30-11"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-30-12" name="__codelineno-30-12" href="#__codelineno-30-12"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-13" name="__codelineno-30-13" href="#__codelineno-30-13"></a>
<a id="__codelineno-30-14" name="__codelineno-30-14" href="#__codelineno-30-14"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-30-15" name="__codelineno-30-15" href="#__codelineno-30-15"></a><span class="w"> </span><span class="nx">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-16" name="__codelineno-30-16" href="#__codelineno-30-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-30-17" name="__codelineno-30-17" href="#__codelineno-30-17"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-18" name="__codelineno-30-18" href="#__codelineno-30-18"></a>
<a id="__codelineno-30-19" name="__codelineno-30-19" href="#__codelineno-30-19"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-30-20" name="__codelineno-30-20" href="#__codelineno-30-20"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-21" name="__codelineno-30-21" href="#__codelineno-30-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-30-22" name="__codelineno-30-22" href="#__codelineno-30-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-23" name="__codelineno-30-23" href="#__codelineno-30-23"></a>
<a id="__codelineno-30-24" name="__codelineno-30-24" href="#__codelineno-30-24"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-30-25" name="__codelineno-30-25" href="#__codelineno-30-25"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-26" name="__codelineno-30-26" href="#__codelineno-30-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-30-27" name="__codelineno-30-27" href="#__codelineno-30-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-28" name="__codelineno-30-28" href="#__codelineno-30-28"></a>
<a id="__codelineno-30-29" name="__codelineno-30-29" href="#__codelineno-30-29"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-30-30" name="__codelineno-30-30" href="#__codelineno-30-30"></a><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-31" name="__codelineno-30-31" href="#__codelineno-30-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-30-32" name="__codelineno-30-32" href="#__codelineno-30-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-30-33" name="__codelineno-30-33" href="#__codelineno-30-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-30-34" name="__codelineno-30-34" href="#__codelineno-30-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">();</span>
<a id="__codelineno-30-35" name="__codelineno-30-35" href="#__codelineno-30-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-36" name="__codelineno-30-36" href="#__codelineno-30-36"></a>
<a id="__codelineno-30-37" name="__codelineno-30-37" href="#__codelineno-30-37"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-30-38" name="__codelineno-30-38" href="#__codelineno-30-38"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-39" name="__codelineno-30-39" href="#__codelineno-30-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-40" name="__codelineno-30-40" href="#__codelineno-30-40"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-30-41" name="__codelineno-30-41" href="#__codelineno-30-41"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-30-42" name="__codelineno-30-42" href="#__codelineno-30-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-43" name="__codelineno-30-43" href="#__codelineno-30-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-30-44" name="__codelineno-30-44" href="#__codelineno-30-44"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-30-45" name="__codelineno-30-45" href="#__codelineno-30-45"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-30-46" name="__codelineno-30-46" href="#__codelineno-30-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-30-47" name="__codelineno-30-47" href="#__codelineno-30-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-30-48" name="__codelineno-30-48" href="#__codelineno-30-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-30-49" name="__codelineno-30-49" href="#__codelineno-30-49"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-50" name="__codelineno-30-50" href="#__codelineno-30-50"></a>
<a id="__codelineno-30-51" name="__codelineno-30-51" href="#__codelineno-30-51"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-30-52" name="__codelineno-30-52" href="#__codelineno-30-52"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-53" name="__codelineno-30-53" href="#__codelineno-30-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-54" name="__codelineno-30-54" href="#__codelineno-30-54"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-30-55" name="__codelineno-30-55" href="#__codelineno-30-55"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-30-56" name="__codelineno-30-56" href="#__codelineno-30-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-57" name="__codelineno-30-57" href="#__codelineno-30-57"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-30-58" name="__codelineno-30-58" href="#__codelineno-30-58"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">);</span>
<a id="__codelineno-30-59" name="__codelineno-30-59" href="#__codelineno-30-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-30-60" name="__codelineno-30-60" href="#__codelineno-30-60"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-30-61" name="__codelineno-30-61" href="#__codelineno-30-61"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-30-62" name="__codelineno-30-62" href="#__codelineno-30-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-63" name="__codelineno-30-63" href="#__codelineno-30-63"></a>
<a id="__codelineno-30-64" name="__codelineno-30-64" href="#__codelineno-30-64"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-30-65" name="__codelineno-30-65" href="#__codelineno-30-65"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-66" name="__codelineno-30-66" href="#__codelineno-30-66"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">();</span>
<a id="__codelineno-30-67" name="__codelineno-30-67" href="#__codelineno-30-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-30-68" name="__codelineno-30-68" href="#__codelineno-30-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-30-69" name="__codelineno-30-69" href="#__codelineno-30-69"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-30-70" name="__codelineno-30-70" href="#__codelineno-30-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-30-71" name="__codelineno-30-71" href="#__codelineno-30-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-72" name="__codelineno-30-72" href="#__codelineno-30-72"></a>
<a id="__codelineno-30-73" name="__codelineno-30-73" href="#__codelineno-30-73"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-30-74" name="__codelineno-30-74" href="#__codelineno-30-74"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-75" name="__codelineno-30-75" href="#__codelineno-30-75"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">();</span>
<a id="__codelineno-30-76" name="__codelineno-30-76" href="#__codelineno-30-76"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-30-77" name="__codelineno-30-77" href="#__codelineno-30-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-30-78" name="__codelineno-30-78" href="#__codelineno-30-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-79" name="__codelineno-30-79" href="#__codelineno-30-79"></a>
<a id="__codelineno-30-80" name="__codelineno-30-80" href="#__codelineno-30-80"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-30-81" name="__codelineno-30-81" href="#__codelineno-30-81"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-82" name="__codelineno-30-82" href="#__codelineno-30-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-30-83" name="__codelineno-30-83" href="#__codelineno-30-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">];</span>
<a id="__codelineno-30-84" name="__codelineno-30-84" href="#__codelineno-30-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-85" name="__codelineno-30-85" href="#__codelineno-30-85"></a>
<a id="__codelineno-30-86" name="__codelineno-30-86" href="#__codelineno-30-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-30-87" name="__codelineno-30-87" href="#__codelineno-30-87"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-88" name="__codelineno-30-88" href="#__codelineno-30-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-30-89" name="__codelineno-30-89" href="#__codelineno-30-89"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-30-90" name="__codelineno-30-90" href="#__codelineno-30-90"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-30-91" name="__codelineno-30-91" href="#__codelineno-30-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">];</span>
<a id="__codelineno-30-92" name="__codelineno-30-92" href="#__codelineno-30-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-93" name="__codelineno-30-93" href="#__codelineno-30-93"></a>
<a id="__codelineno-30-94" name="__codelineno-30-94" href="#__codelineno-30-94"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-30-95" name="__codelineno-30-95" href="#__codelineno-30-95"></a><span class="w"> </span><span class="nx">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-96" name="__codelineno-30-96" href="#__codelineno-30-96"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-30-97" name="__codelineno-30-97" href="#__codelineno-30-97"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-30-98" name="__codelineno-30-98" href="#__codelineno-30-98"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-30-99" name="__codelineno-30-99" href="#__codelineno-30-99"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)];</span>
<a id="__codelineno-30-100" name="__codelineno-30-100" href="#__codelineno-30-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-101" name="__codelineno-30-101" href="#__codelineno-30-101"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</span>
<a id="__codelineno-30-102" name="__codelineno-30-102" href="#__codelineno-30-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-30-103" name="__codelineno-30-103" href="#__codelineno-30-103"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.ts</span><pre><span></span><code><a id="__codelineno-31-1" name="__codelineno-31-1" href="#__codelineno-31-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-31-2" name="__codelineno-31-2" href="#__codelineno-31-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-3" name="__codelineno-31-3" href="#__codelineno-31-3"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">nums</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[];</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-31-4" name="__codelineno-31-4" href="#__codelineno-31-4"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">front</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-31-5" name="__codelineno-31-5" href="#__codelineno-31-5"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">queSize</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-31-6" name="__codelineno-31-6" href="#__codelineno-31-6"></a>
<a id="__codelineno-31-7" name="__codelineno-31-7" href="#__codelineno-31-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-31-8" name="__codelineno-31-8" href="#__codelineno-31-8"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">capacity</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-9" name="__codelineno-31-9" href="#__codelineno-31-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">capacity</span><span class="p">);</span>
<a id="__codelineno-31-10" name="__codelineno-31-10" href="#__codelineno-31-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-31-11" name="__codelineno-31-11" href="#__codelineno-31-11"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-31-12" name="__codelineno-31-12" href="#__codelineno-31-12"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-13" name="__codelineno-31-13" href="#__codelineno-31-13"></a>
<a id="__codelineno-31-14" name="__codelineno-31-14" href="#__codelineno-31-14"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-31-15" name="__codelineno-31-15" href="#__codelineno-31-15"></a><span class="w"> </span><span class="nx">capacity</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-16" name="__codelineno-31-16" href="#__codelineno-31-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-31-17" name="__codelineno-31-17" href="#__codelineno-31-17"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-18" name="__codelineno-31-18" href="#__codelineno-31-18"></a>
<a id="__codelineno-31-19" name="__codelineno-31-19" href="#__codelineno-31-19"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-31-20" name="__codelineno-31-20" href="#__codelineno-31-20"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-21" name="__codelineno-31-21" href="#__codelineno-31-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-31-22" name="__codelineno-31-22" href="#__codelineno-31-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-23" name="__codelineno-31-23" href="#__codelineno-31-23"></a>
<a id="__codelineno-31-24" name="__codelineno-31-24" href="#__codelineno-31-24"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-31-25" name="__codelineno-31-25" href="#__codelineno-31-25"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-26" name="__codelineno-31-26" href="#__codelineno-31-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-31-27" name="__codelineno-31-27" href="#__codelineno-31-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-28" name="__codelineno-31-28" href="#__codelineno-31-28"></a>
<a id="__codelineno-31-29" name="__codelineno-31-29" href="#__codelineno-31-29"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-31-30" name="__codelineno-31-30" href="#__codelineno-31-30"></a><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-31" name="__codelineno-31-31" href="#__codelineno-31-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-31-32" name="__codelineno-31-32" href="#__codelineno-31-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-31-33" name="__codelineno-31-33" href="#__codelineno-31-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-31-34" name="__codelineno-31-34" href="#__codelineno-31-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">();</span>
<a id="__codelineno-31-35" name="__codelineno-31-35" href="#__codelineno-31-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-36" name="__codelineno-31-36" href="#__codelineno-31-36"></a>
<a id="__codelineno-31-37" name="__codelineno-31-37" href="#__codelineno-31-37"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-31-38" name="__codelineno-31-38" href="#__codelineno-31-38"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-39" name="__codelineno-31-39" href="#__codelineno-31-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-40" name="__codelineno-31-40" href="#__codelineno-31-40"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-31-41" name="__codelineno-31-41" href="#__codelineno-31-41"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-31-42" name="__codelineno-31-42" href="#__codelineno-31-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-43" name="__codelineno-31-43" href="#__codelineno-31-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-31-44" name="__codelineno-31-44" href="#__codelineno-31-44"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-31-45" name="__codelineno-31-45" href="#__codelineno-31-45"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-31-46" name="__codelineno-31-46" href="#__codelineno-31-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-31-47" name="__codelineno-31-47" href="#__codelineno-31-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-31-48" name="__codelineno-31-48" href="#__codelineno-31-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-31-49" name="__codelineno-31-49" href="#__codelineno-31-49"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-50" name="__codelineno-31-50" href="#__codelineno-31-50"></a>
<a id="__codelineno-31-51" name="__codelineno-31-51" href="#__codelineno-31-51"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-31-52" name="__codelineno-31-52" href="#__codelineno-31-52"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-53" name="__codelineno-31-53" href="#__codelineno-31-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-54" name="__codelineno-31-54" href="#__codelineno-31-54"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-31-55" name="__codelineno-31-55" href="#__codelineno-31-55"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-31-56" name="__codelineno-31-56" href="#__codelineno-31-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-57" name="__codelineno-31-57" href="#__codelineno-31-57"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-31-58" name="__codelineno-31-58" href="#__codelineno-31-58"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">rear</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">);</span>
<a id="__codelineno-31-59" name="__codelineno-31-59" href="#__codelineno-31-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-31-60" name="__codelineno-31-60" href="#__codelineno-31-60"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-31-61" name="__codelineno-31-61" href="#__codelineno-31-61"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-31-62" name="__codelineno-31-62" href="#__codelineno-31-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-63" name="__codelineno-31-63" href="#__codelineno-31-63"></a>
<a id="__codelineno-31-64" name="__codelineno-31-64" href="#__codelineno-31-64"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-31-65" name="__codelineno-31-65" href="#__codelineno-31-65"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-66" name="__codelineno-31-66" href="#__codelineno-31-66"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">();</span>
<a id="__codelineno-31-67" name="__codelineno-31-67" href="#__codelineno-31-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-31-68" name="__codelineno-31-68" href="#__codelineno-31-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-31-69" name="__codelineno-31-69" href="#__codelineno-31-69"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-31-70" name="__codelineno-31-70" href="#__codelineno-31-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-31-71" name="__codelineno-31-71" href="#__codelineno-31-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-72" name="__codelineno-31-72" href="#__codelineno-31-72"></a>
<a id="__codelineno-31-73" name="__codelineno-31-73" href="#__codelineno-31-73"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-31-74" name="__codelineno-31-74" href="#__codelineno-31-74"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-75" name="__codelineno-31-75" href="#__codelineno-31-75"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">();</span>
<a id="__codelineno-31-76" name="__codelineno-31-76" href="#__codelineno-31-76"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-31-77" name="__codelineno-31-77" href="#__codelineno-31-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-31-78" name="__codelineno-31-78" href="#__codelineno-31-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-79" name="__codelineno-31-79" href="#__codelineno-31-79"></a>
<a id="__codelineno-31-80" name="__codelineno-31-80" href="#__codelineno-31-80"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-31-81" name="__codelineno-31-81" href="#__codelineno-31-81"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-82" name="__codelineno-31-82" href="#__codelineno-31-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-31-83" name="__codelineno-31-83" href="#__codelineno-31-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">];</span>
<a id="__codelineno-31-84" name="__codelineno-31-84" href="#__codelineno-31-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-85" name="__codelineno-31-85" href="#__codelineno-31-85"></a>
<a id="__codelineno-31-86" name="__codelineno-31-86" href="#__codelineno-31-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-31-87" name="__codelineno-31-87" href="#__codelineno-31-87"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-88" name="__codelineno-31-88" href="#__codelineno-31-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-31-89" name="__codelineno-31-89" href="#__codelineno-31-89"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-31-90" name="__codelineno-31-90" href="#__codelineno-31-90"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-31-91" name="__codelineno-31-91" href="#__codelineno-31-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">];</span>
<a id="__codelineno-31-92" name="__codelineno-31-92" href="#__codelineno-31-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-93" name="__codelineno-31-93" href="#__codelineno-31-93"></a>
<a id="__codelineno-31-94" name="__codelineno-31-94" href="#__codelineno-31-94"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-31-95" name="__codelineno-31-95" href="#__codelineno-31-95"></a><span class="w"> </span><span class="nx">toArray</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-96" name="__codelineno-31-96" href="#__codelineno-31-96"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-31-97" name="__codelineno-31-97" href="#__codelineno-31-97"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">res</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-31-98" name="__codelineno-31-98" href="#__codelineno-31-98"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-31-99" name="__codelineno-31-99" href="#__codelineno-31-99"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)];</span>
<a id="__codelineno-31-100" name="__codelineno-31-100" href="#__codelineno-31-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-101" name="__codelineno-31-101" href="#__codelineno-31-101"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</span>
<a id="__codelineno-31-102" name="__codelineno-31-102" href="#__codelineno-31-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-31-103" name="__codelineno-31-103" href="#__codelineno-31-103"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.dart</span><pre><span></span><code><a id="__codelineno-32-1" name="__codelineno-32-1" href="#__codelineno-32-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-32-2" name="__codelineno-32-2" href="#__codelineno-32-2"></a><span class="kd">class</span><span class="w"> </span><span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-3" name="__codelineno-32-3" href="#__codelineno-32-3"></a><span class="w"> </span><span class="kd">late</span><span class="w"> </span><span class="n">List</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">_nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-32-4" name="__codelineno-32-4" href="#__codelineno-32-4"></a><span class="w"> </span><span class="kd">late</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">_front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-32-5" name="__codelineno-32-5" href="#__codelineno-32-5"></a><span class="w"> </span><span class="kd">late</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">_queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-32-6" name="__codelineno-32-6" href="#__codelineno-32-6"></a>
<a id="__codelineno-32-7" name="__codelineno-32-7" href="#__codelineno-32-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-32-8" name="__codelineno-32-8" href="#__codelineno-32-8"></a><span class="w"> </span><span class="n">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-9" name="__codelineno-32-9" href="#__codelineno-32-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">List</span><span class="p">.</span><span class="n">filled</span><span class="p">(</span><span class="n">capacity</span><span class="p">,</span><span class="w"> </span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-32-10" name="__codelineno-32-10" href="#__codelineno-32-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">_queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-32-11" name="__codelineno-32-11" href="#__codelineno-32-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-12" name="__codelineno-32-12" href="#__codelineno-32-12"></a>
<a id="__codelineno-32-13" name="__codelineno-32-13" href="#__codelineno-32-13"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-32-14" name="__codelineno-32-14" href="#__codelineno-32-14"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-15" name="__codelineno-32-15" href="#__codelineno-32-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_nums</span><span class="p">.</span><span class="n">length</span><span class="p">;</span>
<a id="__codelineno-32-16" name="__codelineno-32-16" href="#__codelineno-32-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-17" name="__codelineno-32-17" href="#__codelineno-32-17"></a>
<a id="__codelineno-32-18" name="__codelineno-32-18" href="#__codelineno-32-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-32-19" name="__codelineno-32-19" href="#__codelineno-32-19"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-20" name="__codelineno-32-20" href="#__codelineno-32-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_queSize</span><span class="p">;</span>
<a id="__codelineno-32-21" name="__codelineno-32-21" href="#__codelineno-32-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-22" name="__codelineno-32-22" href="#__codelineno-32-22"></a>
<a id="__codelineno-32-23" name="__codelineno-32-23" href="#__codelineno-32-23"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-32-24" name="__codelineno-32-24" href="#__codelineno-32-24"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-25" name="__codelineno-32-25" href="#__codelineno-32-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-32-26" name="__codelineno-32-26" href="#__codelineno-32-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-27" name="__codelineno-32-27" href="#__codelineno-32-27"></a>
<a id="__codelineno-32-28" name="__codelineno-32-28" href="#__codelineno-32-28"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-32-29" name="__codelineno-32-29" href="#__codelineno-32-29"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-30" name="__codelineno-32-30" href="#__codelineno-32-30"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-32-31" name="__codelineno-32-31" href="#__codelineno-32-31"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-32-32" name="__codelineno-32-32" href="#__codelineno-32-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-32-33" name="__codelineno-32-33" href="#__codelineno-32-33"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-32-34" name="__codelineno-32-34" href="#__codelineno-32-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-35" name="__codelineno-32-35" href="#__codelineno-32-35"></a>
<a id="__codelineno-32-36" name="__codelineno-32-36" href="#__codelineno-32-36"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-32-37" name="__codelineno-32-37" href="#__codelineno-32-37"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-38" name="__codelineno-32-38" href="#__codelineno-32-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">_queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-39" name="__codelineno-32-39" href="#__codelineno-32-39"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">Exception</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-32-40" name="__codelineno-32-40" href="#__codelineno-32-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-41" name="__codelineno-32-41" href="#__codelineno-32-41"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-32-42" name="__codelineno-32-42" href="#__codelineno-32-42"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 _front 越过数组头部后回到尾部</span>
<a id="__codelineno-32-43" name="__codelineno-32-43" href="#__codelineno-32-43"></a><span class="w"> </span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">_front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-32-44" name="__codelineno-32-44" href="#__codelineno-32-44"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-32-45" name="__codelineno-32-45" href="#__codelineno-32-45"></a><span class="w"> </span><span class="n">_nums</span><span class="p">[</span><span class="n">_front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kt">num</span><span class="p">;</span>
<a id="__codelineno-32-46" name="__codelineno-32-46" href="#__codelineno-32-46"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-32-47" name="__codelineno-32-47" href="#__codelineno-32-47"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-48" name="__codelineno-32-48" href="#__codelineno-32-48"></a>
<a id="__codelineno-32-49" name="__codelineno-32-49" href="#__codelineno-32-49"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-32-50" name="__codelineno-32-50" href="#__codelineno-32-50"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-51" name="__codelineno-32-51" href="#__codelineno-32-51"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">_queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-52" name="__codelineno-32-52" href="#__codelineno-32-52"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">Exception</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-32-53" name="__codelineno-32-53" href="#__codelineno-32-53"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-54" name="__codelineno-32-54" href="#__codelineno-32-54"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-32-55" name="__codelineno-32-55" href="#__codelineno-32-55"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">_front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">_queSize</span><span class="p">);</span>
<a id="__codelineno-32-56" name="__codelineno-32-56" href="#__codelineno-32-56"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-32-57" name="__codelineno-32-57" href="#__codelineno-32-57"></a><span class="w"> </span><span class="n">_nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kt">num</span><span class="p">;</span>
<a id="__codelineno-32-58" name="__codelineno-32-58" href="#__codelineno-32-58"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-32-59" name="__codelineno-32-59" href="#__codelineno-32-59"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-60" name="__codelineno-32-60" href="#__codelineno-32-60"></a>
<a id="__codelineno-32-61" name="__codelineno-32-61" href="#__codelineno-32-61"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-32-62" name="__codelineno-32-62" href="#__codelineno-32-62"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-63" name="__codelineno-32-63" href="#__codelineno-32-63"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-32-64" name="__codelineno-32-64" href="#__codelineno-32-64"></a><span class="w"> </span><span class="c1">// 队首指针向右移动一位</span>
<a id="__codelineno-32-65" name="__codelineno-32-65" href="#__codelineno-32-65"></a><span class="w"> </span><span class="n">_front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">_front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-32-66" name="__codelineno-32-66" href="#__codelineno-32-66"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-32-67" name="__codelineno-32-67" href="#__codelineno-32-67"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kt">num</span><span class="p">;</span>
<a id="__codelineno-32-68" name="__codelineno-32-68" href="#__codelineno-32-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-69" name="__codelineno-32-69" href="#__codelineno-32-69"></a>
<a id="__codelineno-32-70" name="__codelineno-32-70" href="#__codelineno-32-70"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-32-71" name="__codelineno-32-71" href="#__codelineno-32-71"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-72" name="__codelineno-32-72" href="#__codelineno-32-72"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="kt">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-32-73" name="__codelineno-32-73" href="#__codelineno-32-73"></a><span class="w"> </span><span class="n">_queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-32-74" name="__codelineno-32-74" href="#__codelineno-32-74"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kt">num</span><span class="p">;</span>
<a id="__codelineno-32-75" name="__codelineno-32-75" href="#__codelineno-32-75"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-76" name="__codelineno-32-76" href="#__codelineno-32-76"></a>
<a id="__codelineno-32-77" name="__codelineno-32-77" href="#__codelineno-32-77"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-32-78" name="__codelineno-32-78" href="#__codelineno-32-78"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-79" name="__codelineno-32-79" href="#__codelineno-32-79"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-80" name="__codelineno-32-80" href="#__codelineno-32-80"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">Exception</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-32-81" name="__codelineno-32-81" href="#__codelineno-32-81"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-82" name="__codelineno-32-82" href="#__codelineno-32-82"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_nums</span><span class="p">[</span><span class="n">_front</span><span class="p">];</span>
<a id="__codelineno-32-83" name="__codelineno-32-83" href="#__codelineno-32-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-84" name="__codelineno-32-84" href="#__codelineno-32-84"></a>
<a id="__codelineno-32-85" name="__codelineno-32-85" href="#__codelineno-32-85"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-32-86" name="__codelineno-32-86" href="#__codelineno-32-86"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-87" name="__codelineno-32-87" href="#__codelineno-32-87"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-88" name="__codelineno-32-88" href="#__codelineno-32-88"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">Exception</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-32-89" name="__codelineno-32-89" href="#__codelineno-32-89"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-90" name="__codelineno-32-90" href="#__codelineno-32-90"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-32-91" name="__codelineno-32-91" href="#__codelineno-32-91"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">_front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">_queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-32-92" name="__codelineno-32-92" href="#__codelineno-32-92"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">_nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-32-93" name="__codelineno-32-93" href="#__codelineno-32-93"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-94" name="__codelineno-32-94" href="#__codelineno-32-94"></a>
<a id="__codelineno-32-95" name="__codelineno-32-95" href="#__codelineno-32-95"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-32-96" name="__codelineno-32-96" href="#__codelineno-32-96"></a><span class="w"> </span><span class="n">List</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-97" name="__codelineno-32-97" href="#__codelineno-32-97"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-32-98" name="__codelineno-32-98" href="#__codelineno-32-98"></a><span class="w"> </span><span class="n">List</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">List</span><span class="p">.</span><span class="n">filled</span><span class="p">(</span><span class="n">_queSize</span><span class="p">,</span><span class="w"> </span><span class="m">0</span><span class="p">);</span>
<a id="__codelineno-32-99" name="__codelineno-32-99" href="#__codelineno-32-99"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">_queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-32-100" name="__codelineno-32-100" href="#__codelineno-32-100"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">_nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)];</span>
<a id="__codelineno-32-101" name="__codelineno-32-101" href="#__codelineno-32-101"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-102" name="__codelineno-32-102" href="#__codelineno-32-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-32-103" name="__codelineno-32-103" href="#__codelineno-32-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-32-104" name="__codelineno-32-104" href="#__codelineno-32-104"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.rs</span><pre><span></span><code><a id="__codelineno-33-1" name="__codelineno-33-1" href="#__codelineno-33-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-33-2" name="__codelineno-33-2" href="#__codelineno-33-2"></a><span class="k">struct</span> <span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-3" name="__codelineno-33-3" href="#__codelineno-33-3"></a><span class="w"> </span><span class="n">nums</span>: <span class="nb">Vec</span><span class="o">&lt;</span><span class="kt">i32</span><span class="o">&gt;</span><span class="p">,</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-33-4" name="__codelineno-33-4" href="#__codelineno-33-4"></a><span class="w"> </span><span class="n">front</span>: <span class="kt">usize</span><span class="p">,</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-33-5" name="__codelineno-33-5" href="#__codelineno-33-5"></a><span class="w"> </span><span class="n">que_size</span>: <span class="kt">usize</span><span class="p">,</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-33-6" name="__codelineno-33-6" href="#__codelineno-33-6"></a><span class="p">}</span>
<a id="__codelineno-33-7" name="__codelineno-33-7" href="#__codelineno-33-7"></a>
<a id="__codelineno-33-8" name="__codelineno-33-8" href="#__codelineno-33-8"></a><span class="k">impl</span><span class="w"> </span><span class="n">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-9" name="__codelineno-33-9" href="#__codelineno-33-9"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-33-10" name="__codelineno-33-10" href="#__codelineno-33-10"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">new</span><span class="p">(</span><span class="n">capacity</span>: <span class="kt">usize</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nc">Self</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-11" name="__codelineno-33-11" href="#__codelineno-33-11"></a><span class="w"> </span><span class="bp">Self</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-12" name="__codelineno-33-12" href="#__codelineno-33-12"></a><span class="w"> </span><span class="n">nums</span>: <span class="nc">vec</span><span class="o">!</span><span class="p">[</span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">capacity</span><span class="p">],</span>
<a id="__codelineno-33-13" name="__codelineno-33-13" href="#__codelineno-33-13"></a><span class="w"> </span><span class="n">front</span>: <span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-33-14" name="__codelineno-33-14" href="#__codelineno-33-14"></a><span class="w"> </span><span class="n">que_size</span>: <span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-33-15" name="__codelineno-33-15" href="#__codelineno-33-15"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-16" name="__codelineno-33-16" href="#__codelineno-33-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-17" name="__codelineno-33-17" href="#__codelineno-33-17"></a>
<a id="__codelineno-33-18" name="__codelineno-33-18" href="#__codelineno-33-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-33-19" name="__codelineno-33-19" href="#__codelineno-33-19"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">capacity</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">usize</span> <span class="p">{</span>
<a id="__codelineno-33-20" name="__codelineno-33-20" href="#__codelineno-33-20"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">.</span><span class="n">len</span><span class="p">()</span>
<a id="__codelineno-33-21" name="__codelineno-33-21" href="#__codelineno-33-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-22" name="__codelineno-33-22" href="#__codelineno-33-22"></a>
<a id="__codelineno-33-23" name="__codelineno-33-23" href="#__codelineno-33-23"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-33-24" name="__codelineno-33-24" href="#__codelineno-33-24"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">size</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">usize</span> <span class="p">{</span>
<a id="__codelineno-33-25" name="__codelineno-33-25" href="#__codelineno-33-25"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span>
<a id="__codelineno-33-26" name="__codelineno-33-26" href="#__codelineno-33-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-27" name="__codelineno-33-27" href="#__codelineno-33-27"></a>
<a id="__codelineno-33-28" name="__codelineno-33-28" href="#__codelineno-33-28"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-33-29" name="__codelineno-33-29" href="#__codelineno-33-29"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">is_empty</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">bool</span> <span class="p">{</span>
<a id="__codelineno-33-30" name="__codelineno-33-30" href="#__codelineno-33-30"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
<a id="__codelineno-33-31" name="__codelineno-33-31" href="#__codelineno-33-31"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-32" name="__codelineno-33-32" href="#__codelineno-33-32"></a>
<a id="__codelineno-33-33" name="__codelineno-33-33" href="#__codelineno-33-33"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-33-34" name="__codelineno-33-34" href="#__codelineno-33-34"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">index</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">i</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">usize</span> <span class="p">{</span>
<a id="__codelineno-33-35" name="__codelineno-33-35" href="#__codelineno-33-35"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-33-36" name="__codelineno-33-36" href="#__codelineno-33-36"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后,回到头部</span>
<a id="__codelineno-33-37" name="__codelineno-33-37" href="#__codelineno-33-37"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-33-38" name="__codelineno-33-38" href="#__codelineno-33-38"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">((</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">usize</span><span class="p">;</span>
<a id="__codelineno-33-39" name="__codelineno-33-39" href="#__codelineno-33-39"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-40" name="__codelineno-33-40" href="#__codelineno-33-40"></a>
<a id="__codelineno-33-41" name="__codelineno-33-41" href="#__codelineno-33-41"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-33-42" name="__codelineno-33-42" href="#__codelineno-33-42"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">push_first</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-43" name="__codelineno-33-43" href="#__codelineno-33-43"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-44" name="__codelineno-33-44" href="#__codelineno-33-44"></a><span class="w"> </span><span class="fm">println!</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-33-45" name="__codelineno-33-45" href="#__codelineno-33-45"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-33-46" name="__codelineno-33-46" href="#__codelineno-33-46"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-47" name="__codelineno-33-47" href="#__codelineno-33-47"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-33-48" name="__codelineno-33-48" href="#__codelineno-33-48"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-33-49" name="__codelineno-33-49" href="#__codelineno-33-49"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-33-50" name="__codelineno-33-50" href="#__codelineno-33-50"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-33-51" name="__codelineno-33-51" href="#__codelineno-33-51"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">[</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-33-52" name="__codelineno-33-52" href="#__codelineno-33-52"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-33-53" name="__codelineno-33-53" href="#__codelineno-33-53"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-54" name="__codelineno-33-54" href="#__codelineno-33-54"></a>
<a id="__codelineno-33-55" name="__codelineno-33-55" href="#__codelineno-33-55"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-33-56" name="__codelineno-33-56" href="#__codelineno-33-56"></a><span class="w"> </span><span class="k">pub</span><span class="w"> </span><span class="k">fn</span> <span class="nf">push_last</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span>: <span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-57" name="__codelineno-33-57" href="#__codelineno-33-57"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-58" name="__codelineno-33-58" href="#__codelineno-33-58"></a><span class="w"> </span><span class="fm">println!</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-33-59" name="__codelineno-33-59" href="#__codelineno-33-59"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-33-60" name="__codelineno-33-60" href="#__codelineno-33-60"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-61" name="__codelineno-33-61" href="#__codelineno-33-61"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-33-62" name="__codelineno-33-62" href="#__codelineno-33-62"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="p">);</span>
<a id="__codelineno-33-63" name="__codelineno-33-63" href="#__codelineno-33-63"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-33-64" name="__codelineno-33-64" href="#__codelineno-33-64"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-33-65" name="__codelineno-33-65" href="#__codelineno-33-65"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-33-66" name="__codelineno-33-66" href="#__codelineno-33-66"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-67" name="__codelineno-33-67" href="#__codelineno-33-67"></a>
<a id="__codelineno-33-68" name="__codelineno-33-68" href="#__codelineno-33-68"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-33-69" name="__codelineno-33-69" href="#__codelineno-33-69"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">pop_first</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">i32</span> <span class="p">{</span>
<a id="__codelineno-33-70" name="__codelineno-33-70" href="#__codelineno-33-70"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">peek_first</span><span class="p">();</span>
<a id="__codelineno-33-71" name="__codelineno-33-71" href="#__codelineno-33-71"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-33-72" name="__codelineno-33-72" href="#__codelineno-33-72"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-33-73" name="__codelineno-33-73" href="#__codelineno-33-73"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-33-74" name="__codelineno-33-74" href="#__codelineno-33-74"></a><span class="w"> </span><span class="n">num</span>
<a id="__codelineno-33-75" name="__codelineno-33-75" href="#__codelineno-33-75"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-76" name="__codelineno-33-76" href="#__codelineno-33-76"></a>
<a id="__codelineno-33-77" name="__codelineno-33-77" href="#__codelineno-33-77"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-33-78" name="__codelineno-33-78" href="#__codelineno-33-78"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">pop_last</span><span class="p">(</span><span class="o">&amp;</span><span class="k">mut</span><span class="w"> </span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">i32</span> <span class="p">{</span>
<a id="__codelineno-33-79" name="__codelineno-33-79" href="#__codelineno-33-79"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">peek_last</span><span class="p">();</span>
<a id="__codelineno-33-80" name="__codelineno-33-80" href="#__codelineno-33-80"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-33-81" name="__codelineno-33-81" href="#__codelineno-33-81"></a><span class="w"> </span><span class="n">num</span>
<a id="__codelineno-33-82" name="__codelineno-33-82" href="#__codelineno-33-82"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-83" name="__codelineno-33-83" href="#__codelineno-33-83"></a>
<a id="__codelineno-33-84" name="__codelineno-33-84" href="#__codelineno-33-84"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-33-85" name="__codelineno-33-85" href="#__codelineno-33-85"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">peek_first</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">i32</span> <span class="p">{</span>
<a id="__codelineno-33-86" name="__codelineno-33-86" href="#__codelineno-33-86"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">is_empty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="fm">panic!</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-33-87" name="__codelineno-33-87" href="#__codelineno-33-87"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">[</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">]</span>
<a id="__codelineno-33-88" name="__codelineno-33-88" href="#__codelineno-33-88"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-89" name="__codelineno-33-89" href="#__codelineno-33-89"></a>
<a id="__codelineno-33-90" name="__codelineno-33-90" href="#__codelineno-33-90"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-33-91" name="__codelineno-33-91" href="#__codelineno-33-91"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">peek_last</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="kt">i32</span> <span class="p">{</span>
<a id="__codelineno-33-92" name="__codelineno-33-92" href="#__codelineno-33-92"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">is_empty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="fm">panic!</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-33-93" name="__codelineno-33-93" href="#__codelineno-33-93"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-33-94" name="__codelineno-33-94" href="#__codelineno-33-94"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-33-95" name="__codelineno-33-95" href="#__codelineno-33-95"></a><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">]</span>
<a id="__codelineno-33-96" name="__codelineno-33-96" href="#__codelineno-33-96"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-97" name="__codelineno-33-97" href="#__codelineno-33-97"></a>
<a id="__codelineno-33-98" name="__codelineno-33-98" href="#__codelineno-33-98"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-33-99" name="__codelineno-33-99" href="#__codelineno-33-99"></a><span class="w"> </span><span class="k">fn</span> <span class="nf">to_array</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">)</span><span class="w"> </span>-&gt; <span class="nb">Vec</span><span class="o">&lt;</span><span class="kt">i32</span><span class="o">&gt;</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-100" name="__codelineno-33-100" href="#__codelineno-33-100"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-33-101" name="__codelineno-33-101" href="#__codelineno-33-101"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="fm">vec!</span><span class="p">[</span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="p">];</span>
<a id="__codelineno-33-102" name="__codelineno-33-102" href="#__codelineno-33-102"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-33-103" name="__codelineno-33-103" href="#__codelineno-33-103"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="mi">0</span><span class="o">..</span><span class="bp">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-33-104" name="__codelineno-33-104" href="#__codelineno-33-104"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="bp">self</span><span class="p">.</span><span class="n">nums</span><span class="p">[</span><span class="bp">self</span><span class="p">.</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="kt">i32</span><span class="p">)];</span>
<a id="__codelineno-33-105" name="__codelineno-33-105" href="#__codelineno-33-105"></a><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<a id="__codelineno-33-106" name="__codelineno-33-106" href="#__codelineno-33-106"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-107" name="__codelineno-33-107" href="#__codelineno-33-107"></a><span class="w"> </span><span class="n">res</span>
<a id="__codelineno-33-108" name="__codelineno-33-108" href="#__codelineno-33-108"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-33-109" name="__codelineno-33-109" href="#__codelineno-33-109"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.c</span><pre><span></span><code><a id="__codelineno-34-1" name="__codelineno-34-1" href="#__codelineno-34-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-34-2" name="__codelineno-34-2" href="#__codelineno-34-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">arrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-3" name="__codelineno-34-3" href="#__codelineno-34-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="o">*</span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储队列元素的数组</span>
<a id="__codelineno-34-4" name="__codelineno-34-4" href="#__codelineno-34-4"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针,指向队首元素</span>
<a id="__codelineno-34-5" name="__codelineno-34-5" href="#__codelineno-34-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾指针,指向队尾 + 1</span>
<a id="__codelineno-34-6" name="__codelineno-34-6" href="#__codelineno-34-6"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queCapacity</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队列容量</span>
<a id="__codelineno-34-7" name="__codelineno-34-7" href="#__codelineno-34-7"></a><span class="p">};</span>
<a id="__codelineno-34-8" name="__codelineno-34-8" href="#__codelineno-34-8"></a>
<a id="__codelineno-34-9" name="__codelineno-34-9" href="#__codelineno-34-9"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">arrayDeque</span><span class="w"> </span><span class="n">arrayDeque</span><span class="p">;</span>
<a id="__codelineno-34-10" name="__codelineno-34-10" href="#__codelineno-34-10"></a>
<a id="__codelineno-34-11" name="__codelineno-34-11" href="#__codelineno-34-11"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-34-12" name="__codelineno-34-12" href="#__codelineno-34-12"></a><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="nf">newArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-13" name="__codelineno-34-13" href="#__codelineno-34-13"></a><span class="w"> </span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">arrayDeque</span><span class="p">));</span>
<a id="__codelineno-34-14" name="__codelineno-34-14" href="#__codelineno-34-14"></a><span class="w"> </span><span class="c1">// 初始化数组</span>
<a id="__codelineno-34-15" name="__codelineno-34-15" href="#__codelineno-34-15"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-34-16" name="__codelineno-34-16" href="#__codelineno-34-16"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">);</span>
<a id="__codelineno-34-17" name="__codelineno-34-17" href="#__codelineno-34-17"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-34-18" name="__codelineno-34-18" href="#__codelineno-34-18"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-34-19" name="__codelineno-34-19" href="#__codelineno-34-19"></a><span class="p">}</span>
<a id="__codelineno-34-20" name="__codelineno-34-20" href="#__codelineno-34-20"></a>
<a id="__codelineno-34-21" name="__codelineno-34-21" href="#__codelineno-34-21"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-34-22" name="__codelineno-34-22" href="#__codelineno-34-22"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delArrayDeque</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-23" name="__codelineno-34-23" href="#__codelineno-34-23"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">);</span>
<a id="__codelineno-34-24" name="__codelineno-34-24" href="#__codelineno-34-24"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-34-25" name="__codelineno-34-25" href="#__codelineno-34-25"></a><span class="p">}</span>
<a id="__codelineno-34-26" name="__codelineno-34-26" href="#__codelineno-34-26"></a>
<a id="__codelineno-34-27" name="__codelineno-34-27" href="#__codelineno-34-27"></a><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-34-28" name="__codelineno-34-28" href="#__codelineno-34-28"></a><span class="kt">int</span><span class="w"> </span><span class="nf">capacity</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-29" name="__codelineno-34-29" href="#__codelineno-34-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">;</span>
<a id="__codelineno-34-30" name="__codelineno-34-30" href="#__codelineno-34-30"></a><span class="p">}</span>
<a id="__codelineno-34-31" name="__codelineno-34-31" href="#__codelineno-34-31"></a>
<a id="__codelineno-34-32" name="__codelineno-34-32" href="#__codelineno-34-32"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-34-33" name="__codelineno-34-33" href="#__codelineno-34-33"></a><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-34" name="__codelineno-34-34" href="#__codelineno-34-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-34-35" name="__codelineno-34-35" href="#__codelineno-34-35"></a><span class="p">}</span>
<a id="__codelineno-34-36" name="__codelineno-34-36" href="#__codelineno-34-36"></a>
<a id="__codelineno-34-37" name="__codelineno-34-37" href="#__codelineno-34-37"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-34-38" name="__codelineno-34-38" href="#__codelineno-34-38"></a><span class="kt">bool</span><span class="w"> </span><span class="nf">empty</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-39" name="__codelineno-34-39" href="#__codelineno-34-39"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-34-40" name="__codelineno-34-40" href="#__codelineno-34-40"></a><span class="p">}</span>
<a id="__codelineno-34-41" name="__codelineno-34-41" href="#__codelineno-34-41"></a>
<a id="__codelineno-34-42" name="__codelineno-34-42" href="#__codelineno-34-42"></a><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-34-43" name="__codelineno-34-43" href="#__codelineno-34-43"></a><span class="kt">int</span><span class="w"> </span><span class="nf">dequeIndex</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-44" name="__codelineno-34-44" href="#__codelineno-34-44"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-34-45" name="__codelineno-34-45" href="#__codelineno-34-45"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部时,回到头部</span>
<a id="__codelineno-34-46" name="__codelineno-34-46" href="#__codelineno-34-46"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后,回到尾部</span>
<a id="__codelineno-34-47" name="__codelineno-34-47" href="#__codelineno-34-47"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">((</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">));</span>
<a id="__codelineno-34-48" name="__codelineno-34-48" href="#__codelineno-34-48"></a><span class="p">}</span>
<a id="__codelineno-34-49" name="__codelineno-34-49" href="#__codelineno-34-49"></a>
<a id="__codelineno-34-50" name="__codelineno-34-50" href="#__codelineno-34-50"></a><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-34-51" name="__codelineno-34-51" href="#__codelineno-34-51"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-52" name="__codelineno-34-52" href="#__codelineno-34-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-53" name="__codelineno-34-53" href="#__codelineno-34-53"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;双向队列已满</span><span class="se">\r\n</span><span class="s">&quot;</span><span class="p">);</span>
<a id="__codelineno-34-54" name="__codelineno-34-54" href="#__codelineno-34-54"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-34-55" name="__codelineno-34-55" href="#__codelineno-34-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-34-56" name="__codelineno-34-56" href="#__codelineno-34-56"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-34-57" name="__codelineno-34-57" href="#__codelineno-34-57"></a><span class="w"> </span><span class="c1">// 通过取余操作,实现 front 越过数组头部回到尾部</span>
<a id="__codelineno-34-58" name="__codelineno-34-58" href="#__codelineno-34-58"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-34-59" name="__codelineno-34-59" href="#__codelineno-34-59"></a><span class="w"> </span><span class="c1">// 将 num 添加到队首</span>
<a id="__codelineno-34-60" name="__codelineno-34-60" href="#__codelineno-34-60"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-34-61" name="__codelineno-34-61" href="#__codelineno-34-61"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-34-62" name="__codelineno-34-62" href="#__codelineno-34-62"></a><span class="p">}</span>
<a id="__codelineno-34-63" name="__codelineno-34-63" href="#__codelineno-34-63"></a>
<a id="__codelineno-34-64" name="__codelineno-34-64" href="#__codelineno-34-64"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-34-65" name="__codelineno-34-65" href="#__codelineno-34-65"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-66" name="__codelineno-34-66" href="#__codelineno-34-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-67" name="__codelineno-34-67" href="#__codelineno-34-67"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;双向队列已满</span><span class="se">\r\n</span><span class="s">&quot;</span><span class="p">);</span>
<a id="__codelineno-34-68" name="__codelineno-34-68" href="#__codelineno-34-68"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-34-69" name="__codelineno-34-69" href="#__codelineno-34-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-34-70" name="__codelineno-34-70" href="#__codelineno-34-70"></a><span class="w"> </span><span class="c1">// 计算尾指针,指向队尾索引 + 1</span>
<a id="__codelineno-34-71" name="__codelineno-34-71" href="#__codelineno-34-71"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-34-72" name="__codelineno-34-72" href="#__codelineno-34-72"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-34-73" name="__codelineno-34-73" href="#__codelineno-34-73"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-34-74" name="__codelineno-34-74" href="#__codelineno-34-74"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-34-75" name="__codelineno-34-75" href="#__codelineno-34-75"></a><span class="p">}</span>
<a id="__codelineno-34-76" name="__codelineno-34-76" href="#__codelineno-34-76"></a>
<a id="__codelineno-34-77" name="__codelineno-34-77" href="#__codelineno-34-77"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-34-78" name="__codelineno-34-78" href="#__codelineno-34-78"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-79" name="__codelineno-34-79" href="#__codelineno-34-79"></a><span class="w"> </span><span class="c1">// 访问异常:双向队列为空</span>
<a id="__codelineno-34-80" name="__codelineno-34-80" href="#__codelineno-34-80"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-34-81" name="__codelineno-34-81" href="#__codelineno-34-81"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-34-82" name="__codelineno-34-82" href="#__codelineno-34-82"></a><span class="p">}</span>
<a id="__codelineno-34-83" name="__codelineno-34-83" href="#__codelineno-34-83"></a>
<a id="__codelineno-34-84" name="__codelineno-34-84" href="#__codelineno-34-84"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-34-85" name="__codelineno-34-85" href="#__codelineno-34-85"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-86" name="__codelineno-34-86" href="#__codelineno-34-86"></a><span class="w"> </span><span class="c1">// 访问异常:双向队列为空</span>
<a id="__codelineno-34-87" name="__codelineno-34-87" href="#__codelineno-34-87"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-34-88" name="__codelineno-34-88" href="#__codelineno-34-88"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-34-89" name="__codelineno-34-89" href="#__codelineno-34-89"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-34-90" name="__codelineno-34-90" href="#__codelineno-34-90"></a><span class="p">}</span>
<a id="__codelineno-34-91" name="__codelineno-34-91" href="#__codelineno-34-91"></a>
<a id="__codelineno-34-92" name="__codelineno-34-92" href="#__codelineno-34-92"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-34-93" name="__codelineno-34-93" href="#__codelineno-34-93"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-94" name="__codelineno-34-94" href="#__codelineno-34-94"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-34-95" name="__codelineno-34-95" href="#__codelineno-34-95"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-34-96" name="__codelineno-34-96" href="#__codelineno-34-96"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-34-97" name="__codelineno-34-97" href="#__codelineno-34-97"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-34-98" name="__codelineno-34-98" href="#__codelineno-34-98"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-34-99" name="__codelineno-34-99" href="#__codelineno-34-99"></a><span class="p">}</span>
<a id="__codelineno-34-100" name="__codelineno-34-100" href="#__codelineno-34-100"></a>
<a id="__codelineno-34-101" name="__codelineno-34-101" href="#__codelineno-34-101"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-34-102" name="__codelineno-34-102" href="#__codelineno-34-102"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-103" name="__codelineno-34-103" href="#__codelineno-34-103"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-34-104" name="__codelineno-34-104" href="#__codelineno-34-104"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-34-105" name="__codelineno-34-105" href="#__codelineno-34-105"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-34-106" name="__codelineno-34-106" href="#__codelineno-34-106"></a><span class="p">}</span>
<a id="__codelineno-34-107" name="__codelineno-34-107" href="#__codelineno-34-107"></a>
<a id="__codelineno-34-108" name="__codelineno-34-108" href="#__codelineno-34-108"></a><span class="cm">/* 打印队列 */</span>
<a id="__codelineno-34-109" name="__codelineno-34-109" href="#__codelineno-34-109"></a><span class="kt">void</span><span class="w"> </span><span class="nf">printArrayDeque</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-110" name="__codelineno-34-110" href="#__codelineno-34-110"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-34-111" name="__codelineno-34-111" href="#__codelineno-34-111"></a><span class="w"> </span><span class="c1">// 拷贝</span>
<a id="__codelineno-34-112" name="__codelineno-34-112" href="#__codelineno-34-112"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-34-113" name="__codelineno-34-113" href="#__codelineno-34-113"></a><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">j</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">];</span>
<a id="__codelineno-34-114" name="__codelineno-34-114" href="#__codelineno-34-114"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-34-115" name="__codelineno-34-115" href="#__codelineno-34-115"></a><span class="w"> </span><span class="n">printArray</span><span class="p">(</span><span class="n">arr</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-34-116" name="__codelineno-34-116" href="#__codelineno-34-116"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.zig</span><pre><span></span><code><a id="__codelineno-35-1" name="__codelineno-35-1" href="#__codelineno-35-1"></a><span class="p">[</span><span class="n">class</span><span class="p">]{</span><span class="n">ArrayDeque</span><span class="p">}</span><span class="o">-</span><span class="p">[</span><span class="n">func</span><span class="p">]{}</span>
</code></pre></div>
</div>
</div>
</div>
<h2 id="533">5.3.3 &nbsp; 双向队列应用<a class="headerlink" href="#533" title="Permanent link">&para;</a></h2>
<p>双向队列兼具栈与队列的逻辑,<strong>因此它可以实现这两者的所有应用场景,同时提供更高的自由度</strong></p>
<p>我们知道,软件的“撤销”功能通常使用栈来实现:系统将每次更改操作 <code>push</code> 到栈中,然后通过 <code>pop</code> 实现撤销。然而,考虑到系统资源的限制,软件通常会限制撤销的步数(例如仅允许保存 <span class="arithmatex">\(50\)</span> 步)。当栈的长度超过 <span class="arithmatex">\(50\)</span> 时,软件需要在栈底(即队首)执行删除操作。<strong>但栈无法实现该功能,此时就需要使用双向队列来替代栈</strong>。请注意,“撤销”的核心逻辑仍然遵循栈的先入后出原则,只是双向队列能够更加灵活地实现一些额外逻辑。</p>
<!-- Source file information -->
<!-- Was this page helpful? -->
<!-- Previous and next pages link -->
<nav
class="md-footer__inner md-grid"
aria-label="页脚"
>
<!-- Link to previous page -->
<a
href="../queue/"
class="md-footer__link md-footer__link--prev"
aria-label="上一页: 5.2 &amp;nbsp; 队列"
rel="prev"
>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
5.2 &nbsp; 队列
</div>
</div>
</a>
<!-- Link to next page -->
<a
href="../summary/"
class="md-footer__link md-footer__link--next"
aria-label="下一页: 5.4 &amp;nbsp; 小结"
rel="next"
>
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
5.4 &nbsp; 小结
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<!-- Comment system -->
<h5 align="center" id="__comments">欢迎在评论区留下你的见解、疑惑或建议</h5>
<!-- Insert generated snippet here -->
<script
src="https://giscus.app/client.js"
data-repo="krahets/hello-algo"
data-repo-id="R_kgDOIXtSqw"
data-category="Announcements"
data-category-id="DIC_kwDOIXtSq84CSZk_"
data-mapping="pathname"
data-strict="1"
data-reactions-enabled="1"
data-emit-metadata="0"
data-input-position="top"
data-theme="preferred_color_scheme"
data-lang="zh-CN"
crossorigin="anonymous"
async
>
</script>
<!-- Synchronize Giscus theme with palette -->
<script>
var giscus = document.querySelector("script[src*=giscus]")
/* Set palette on initial load */
var palette = __md_get("__palette")
if (palette && typeof palette.color === "object") {
var theme = palette.color.scheme === "slate" ? "dark_dimmed" : "light"
giscus.setAttribute("data-theme", theme)
}
/* Register event handlers after documented loaded */
document.addEventListener("DOMContentLoaded", function() {
var ref = document.querySelector("[data-md-component=palette]")
ref.addEventListener("change", function() {
var palette = __md_get("__palette")
if (palette && typeof palette.color === "object") {
var theme = palette.color.scheme === "slate" ? "dark_dimmed" : "light"
/* Instruct Giscus to change theme */
var frame = document.querySelector(".giscus-frame")
frame.contentWindow.postMessage(
{ giscus: { setConfig: { theme } } },
"https://giscus.app"
)
}
})
})
</script>
</article>
</div>
<script>var tabs=__md_get("__tabs");if(Array.isArray(tabs))e:for(var set of document.querySelectorAll(".tabbed-set")){var tab,labels=set.querySelector(".tabbed-labels");for(tab of tabs)for(var label of labels.getElementsByTagName("label"))if(label.innerText.trim()===tab){var input=document.getElementById(label.htmlFor);input.checked=!0;continue e}}</script>
</div>
<button type="button" class="md-top md-icon" data-md-component="top" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8v12Z"/></svg>
回到页面顶部
</button>
</main>
<footer class="md-footer">
<nav class="md-footer__inner md-grid" aria-label="页脚" >
<a href="../queue/" class="md-footer__link md-footer__link--prev" aria-label="上一页: 5.2 &amp;nbsp; 队列" rel="prev">
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11h12Z"/></svg>
</div>
<div class="md-footer__title">
<span class="md-footer__direction">
上一页
</span>
<div class="md-ellipsis">
5.2 &nbsp; 队列
</div>
</div>
</a>
<a href="../summary/" class="md-footer__link md-footer__link--next" aria-label="下一页: 5.4 &amp;nbsp; 小结" rel="next">
<div class="md-footer__title">
<span class="md-footer__direction">
下一页
</span>
<div class="md-ellipsis">
5.4 &nbsp; 小结
</div>
</div>
<div class="md-footer__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M4 11v2h12l-5.5 5.5 1.42 1.42L19.84 12l-7.92-7.92L10.5 5.5 16 11H4Z"/></svg>
</div>
</a>
</nav>
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
<div class="md-copyright__highlight">
Copyright &copy; 2022 - 2023 Krahets
</div>
</div>
<div class="md-social">
<a href="https://github.com/krahets" target="_blank" rel="noopener" title="github.com" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 496 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M165.9 397.4c0 2-2.3 3.6-5.2 3.6-3.3.3-5.6-1.3-5.6-3.6 0-2 2.3-3.6 5.2-3.6 3-.3 5.6 1.3 5.6 3.6zm-31.1-4.5c-.7 2 1.3 4.3 4.3 4.9 2.6 1 5.6 0 6.2-2s-1.3-4.3-4.3-5.2c-2.6-.7-5.5.3-6.2 2.3zm44.2-1.7c-2.9.7-4.9 2.6-4.6 4.9.3 2 2.9 3.3 5.9 2.6 2.9-.7 4.9-2.6 4.6-4.6-.3-1.9-3-3.2-5.9-2.9zM244.8 8C106.1 8 0 113.3 0 252c0 110.9 69.8 205.8 169.5 239.2 12.8 2.3 17.3-5.6 17.3-12.1 0-6.2-.3-40.4-.3-61.4 0 0-70 15-84.7-29.8 0 0-11.4-29.1-27.8-36.6 0 0-22.9-15.7 1.6-15.4 0 0 24.9 2 38.6 25.8 21.9 38.6 58.6 27.5 72.9 20.9 2.3-16 8.8-27.1 16-33.7-55.9-6.2-112.3-14.3-112.3-110.5 0-27.5 7.6-41.3 23.6-58.9-2.6-6.5-11.1-33.3 2.6-67.9 20.9-6.5 69 27 69 27 20-5.6 41.5-8.5 62.8-8.5s42.8 2.9 62.8 8.5c0 0 48.1-33.6 69-27 13.7 34.7 5.2 61.4 2.6 67.9 16 17.7 25.8 31.5 25.8 58.9 0 96.5-58.9 104.2-114.8 110.5 9.2 7.9 17 22.9 17 46.4 0 33.7-.3 75.4-.3 83.6 0 6.5 4.6 14.4 17.3 12.1C428.2 457.8 496 362.9 496 252 496 113.3 383.5 8 244.8 8zM97.2 352.9c-1.3 1-1 3.3.7 5.2 1.6 1.6 3.9 2.3 5.2 1 1.3-1 1-3.3-.7-5.2-1.6-1.6-3.9-2.3-5.2-1zm-10.8-8.1c-.7 1.3.3 2.9 2.3 3.9 1.6 1 3.6.7 4.3-.7.7-1.3-.3-2.9-2.3-3.9-2-.6-3.6-.3-4.3.7zm32.4 35.6c-1.6 1.3-1 4.3 1.3 6.2 2.3 2.3 5.2 2.6 6.5 1 1.3-1.3.7-4.3-1.3-6.2-2.2-2.3-5.2-2.6-6.5-1zm-11.4-14.7c-1.6 1-1.6 3.6 0 5.9 1.6 2.3 4.3 3.3 5.6 2.3 1.6-1.3 1.6-3.9 0-6.2-1.4-2.3-4-3.3-5.6-2z"/></svg>
</a>
<a href="https://twitter.com/krahets" target="_blank" rel="noopener" title="twitter.com" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M459.37 151.716c.325 4.548.325 9.097.325 13.645 0 138.72-105.583 298.558-298.558 298.558-59.452 0-114.68-17.219-161.137-47.106 8.447.974 16.568 1.299 25.34 1.299 49.055 0 94.213-16.568 130.274-44.832-46.132-.975-84.792-31.188-98.112-72.772 6.498.974 12.995 1.624 19.818 1.624 9.421 0 18.843-1.3 27.614-3.573-48.081-9.747-84.143-51.98-84.143-102.985v-1.299c13.969 7.797 30.214 12.67 47.431 13.319-28.264-18.843-46.781-51.005-46.781-87.391 0-19.492 5.197-37.36 14.294-52.954 51.655 63.675 129.3 105.258 216.365 109.807-1.624-7.797-2.599-15.918-2.599-24.04 0-57.828 46.782-104.934 104.934-104.934 30.213 0 57.502 12.67 76.67 33.137 23.715-4.548 46.456-13.32 66.599-25.34-7.798 24.366-24.366 44.833-46.132 57.827 21.117-2.273 41.584-8.122 60.426-16.243-14.292 20.791-32.161 39.308-52.628 54.253z"/></svg>
</a>
<a href="https://leetcode.cn/u/jyd/" target="_blank" rel="noopener" title="leetcode.cn" class="md-social__link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 640 512"><!--! Font Awesome Free 6.4.2 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M392.8 1.2c-17-4.9-34.7 5-39.6 22l-128 448c-4.9 17 5 34.7 22 39.6s34.7-5 39.6-22l128-448c4.9-17-5-34.7-22-39.6zm80.6 120.1c-12.5 12.5-12.5 32.8 0 45.3l89.3 89.4-89.4 89.4c-12.5 12.5-12.5 32.8 0 45.3s32.8 12.5 45.3 0l112-112c12.5-12.5 12.5-32.8 0-45.3l-112-112c-12.5-12.5-32.8-12.5-45.3 0zm-306.7 0c-12.5-12.5-32.8-12.5-45.3 0l-112 112c-12.5 12.5-12.5 32.8 0 45.3l112 112c12.5 12.5 32.8 12.5 45.3 0s12.5-32.8 0-45.3L77.3 256l89.4-89.4c12.5-12.5 12.5-32.8 0-45.3z"/></svg>
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"base": "../..", "features": ["content.action.edit", "content.code.annotate", "content.code.copy", "content.tabs.link", "content.tooltips", "navigation.indexes", "navigation.instant", "navigation.top", "navigation.footer", "navigation.tracking", "search.highlight", "search.share", "search.suggest", "toc.follow"], "search": "../../assets/javascripts/workers/search.a264c092.min.js", "translations": {"clipboard.copied": "\u5df2\u590d\u5236", "clipboard.copy": "\u590d\u5236", "search.result.more.one": "\u5728\u8be5\u9875\u4e0a\u8fd8\u6709 1 \u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u7ed3\u679c", "search.result.more.other": "\u5728\u8be5\u9875\u4e0a\u8fd8\u6709 # \u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u7ed3\u679c", "search.result.none": "\u6ca1\u6709\u627e\u5230\u7b26\u5408\u6761\u4ef6\u7684\u7ed3\u679c", "search.result.one": "\u627e\u5230 1 \u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u7ed3\u679c", "search.result.other": "# \u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u7ed3\u679c", "search.result.placeholder": "\u952e\u5165\u4ee5\u5f00\u59cb\u641c\u7d22", "search.result.term.missing": "\u7f3a\u5c11", "select.version": "\u9009\u62e9\u5f53\u524d\u7248\u672c"}}</script>
<script src="../../assets/javascripts/bundle.4e0fa4ba.min.js"></script>
<script src="../../javascripts/mathjax.js"></script>
<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>
<script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
<script>document$.subscribe(() => {const lightbox = GLightbox({"touchNavigation": true, "loop": false, "zoomable": true, "draggable": false, "openEffect": "zoom", "closeEffect": "zoom", "slideEffect": "none"});})</script></body>
</html>