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5.1.1. &nbsp; 栈常用操作
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时间效率
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<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_stack_and_queue/stack.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>
<h1 id="51">5.1. &nbsp;<a class="headerlink" href="#51" title="Permanent link">&para;</a></h1>
<p>「栈 Stack」是一种遵循「先入后出 first in, last out」数据操作规则的线性数据结构。我们可以将栈类比为放在桌面上的一摞盘子如果需要拿出底部的盘子则需要先将上面的盘子依次取出。</p>
<p>“盘子”是一种形象比喻,我们将盘子替换为任意一种元素(例如整数、字符、对象等),就得到了栈数据结构。</p>
<p>我们将这一摞元素的顶部称为「栈顶」,将底部称为「栈底」,将把元素添加到栈顶的操作称为「入栈」,将删除栈顶元素的操作称为「出栈」。</p>
<p><img alt="栈的先入后出规则" src="../stack.assets/stack_operations.png" /></p>
<p align="center"> Fig. 栈的先入后出规则 </p>
<h2 id="511">5.1.1. &nbsp; 栈常用操作<a class="headerlink" href="#511" title="Permanent link">&para;</a></h2>
<p>栈的常用操作见下表,方法名需根据编程语言来确定,此处我们以常见的 <code>push</code> , <code>pop</code> , <code>peek</code> 为例。</p>
<div class="center-table">
<table>
<thead>
<tr>
<th>方法</th>
<th>描述</th>
<th>时间复杂度</th>
</tr>
</thead>
<tbody>
<tr>
<td>push()</td>
<td>元素入栈(添加至栈顶)</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>pop()</td>
<td>栈顶元素出栈</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>peek()</td>
<td>访问栈顶元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
</tbody>
</table>
</div>
<p>我们可以直接使用编程语言实现好的栈类。 某些语言并未专门提供栈类,但我们可以直接把该语言的「数组」或「链表」看作栈来使用,并通过“脑补”来屏蔽无关操作。</p>
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<div class="highlight"><span class="filename">stack.java</span><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a><span class="n">Stack</span><span class="o">&lt;</span><span class="n">Integer</span><span class="o">&gt;</span><span class="w"> </span><span class="n">stack</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">Stack</span><span class="o">&lt;&gt;</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="cm">/* 元素入栈 */</span>
<a id="__codelineno-0-5" name="__codelineno-0-5" href="#__codelineno-0-5"></a><span class="n">stack</span><span class="p">.</span><span class="na">push</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-0-6" name="__codelineno-0-6" href="#__codelineno-0-6"></a><span class="n">stack</span><span class="p">.</span><span class="na">push</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span>
<a id="__codelineno-0-7" name="__codelineno-0-7" href="#__codelineno-0-7"></a><span class="n">stack</span><span class="p">.</span><span class="na">push</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span>
<a id="__codelineno-0-8" name="__codelineno-0-8" href="#__codelineno-0-8"></a><span class="n">stack</span><span class="p">.</span><span class="na">push</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-0-9" name="__codelineno-0-9" href="#__codelineno-0-9"></a><span class="n">stack</span><span class="p">.</span><span class="na">push</span><span class="p">(</span><span class="mi">4</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="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-0-12" name="__codelineno-0-12" href="#__codelineno-0-12"></a><span class="kt">int</span><span class="w"> </span><span class="n">peek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">peek</span><span class="p">();</span>
<a id="__codelineno-0-13" name="__codelineno-0-13" href="#__codelineno-0-13"></a>
<a id="__codelineno-0-14" name="__codelineno-0-14" href="#__codelineno-0-14"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-0-15" name="__codelineno-0-15" href="#__codelineno-0-15"></a><span class="kt">int</span><span class="w"> </span><span class="n">pop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">pop</span><span class="p">();</span>
<a id="__codelineno-0-16" name="__codelineno-0-16" href="#__codelineno-0-16"></a>
<a id="__codelineno-0-17" name="__codelineno-0-17" href="#__codelineno-0-17"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-0-18" name="__codelineno-0-18" href="#__codelineno-0-18"></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">stack</span><span class="p">.</span><span class="na">size</span><span class="p">();</span>
<a id="__codelineno-0-19" name="__codelineno-0-19" href="#__codelineno-0-19"></a>
<a id="__codelineno-0-20" name="__codelineno-0-20" href="#__codelineno-0-20"></a><span class="cm">/* 判断是否为空 */</span>
<a id="__codelineno-0-21" name="__codelineno-0-21" href="#__codelineno-0-21"></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">stack</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">stack.cpp</span><pre><span></span><code><a id="__codelineno-1-1" name="__codelineno-1-1" href="#__codelineno-1-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-1-2" name="__codelineno-1-2" href="#__codelineno-1-2"></a><span class="n">stack</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">stack</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">/* 元素入栈 */</span>
<a id="__codelineno-1-5" name="__codelineno-1-5" href="#__codelineno-1-5"></a><span class="n">stack</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-1-6" name="__codelineno-1-6" href="#__codelineno-1-6"></a><span class="n">stack</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span>
<a id="__codelineno-1-7" name="__codelineno-1-7" href="#__codelineno-1-7"></a><span class="n">stack</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span>
<a id="__codelineno-1-8" name="__codelineno-1-8" href="#__codelineno-1-8"></a><span class="n">stack</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-1-9" name="__codelineno-1-9" href="#__codelineno-1-9"></a><span class="n">stack</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="mi">4</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">/* 访问栈顶元素 */</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">top</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">top</span><span class="p">();</span>
<a id="__codelineno-1-13" name="__codelineno-1-13" href="#__codelineno-1-13"></a>
<a id="__codelineno-1-14" name="__codelineno-1-14" href="#__codelineno-1-14"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-1-15" name="__codelineno-1-15" href="#__codelineno-1-15"></a><span class="n">stack</span><span class="p">.</span><span class="n">pop</span><span class="p">();</span><span class="w"> </span><span class="c1">// 无返回值</span>
<a id="__codelineno-1-16" name="__codelineno-1-16" href="#__codelineno-1-16"></a>
<a id="__codelineno-1-17" name="__codelineno-1-17" href="#__codelineno-1-17"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-1-18" name="__codelineno-1-18" href="#__codelineno-1-18"></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">stack</span><span class="p">.</span><span class="n">size</span><span class="p">();</span>
<a id="__codelineno-1-19" name="__codelineno-1-19" href="#__codelineno-1-19"></a>
<a id="__codelineno-1-20" name="__codelineno-1-20" href="#__codelineno-1-20"></a><span class="cm">/* 判断是否为空 */</span>
<a id="__codelineno-1-21" name="__codelineno-1-21" href="#__codelineno-1-21"></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">stack</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">stack.py</span><pre><span></span><code><a id="__codelineno-2-1" name="__codelineno-2-1" href="#__codelineno-2-1"></a><span class="sd">&quot;&quot;&quot; 初始化栈 &quot;&quot;&quot;</span>
<a id="__codelineno-2-2" name="__codelineno-2-2" href="#__codelineno-2-2"></a><span class="c1"># Python 没有内置的栈类,可以把 List 当作栈来使用 </span>
<a id="__codelineno-2-3" name="__codelineno-2-3" href="#__codelineno-2-3"></a><span class="n">stack</span><span class="p">:</span> <span class="n">List</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="p">[]</span>
<a id="__codelineno-2-4" name="__codelineno-2-4" href="#__codelineno-2-4"></a>
<a id="__codelineno-2-5" name="__codelineno-2-5" href="#__codelineno-2-5"></a><span class="sd">&quot;&quot;&quot; 元素入栈 &quot;&quot;&quot;</span>
<a id="__codelineno-2-6" name="__codelineno-2-6" href="#__codelineno-2-6"></a><span class="n">stack</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-2-7" name="__codelineno-2-7" href="#__codelineno-2-7"></a><span class="n">stack</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span>
<a id="__codelineno-2-8" name="__codelineno-2-8" href="#__codelineno-2-8"></a><span class="n">stack</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span>
<a id="__codelineno-2-9" name="__codelineno-2-9" href="#__codelineno-2-9"></a><span class="n">stack</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-2-10" name="__codelineno-2-10" href="#__codelineno-2-10"></a><span class="n">stack</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-2-11" name="__codelineno-2-11" href="#__codelineno-2-11"></a>
<a id="__codelineno-2-12" name="__codelineno-2-12" href="#__codelineno-2-12"></a><span class="sd">&quot;&quot;&quot; 访问栈顶元素 &quot;&quot;&quot;</span>
<a id="__codelineno-2-13" name="__codelineno-2-13" href="#__codelineno-2-13"></a><span class="n">peek</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">stack</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</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="sd">&quot;&quot;&quot; 元素出栈 &quot;&quot;&quot;</span>
<a id="__codelineno-2-16" name="__codelineno-2-16" href="#__codelineno-2-16"></a><span class="n">pop</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">stack</span><span class="o">.</span><span class="n">pop</span><span class="p">()</span>
<a id="__codelineno-2-17" name="__codelineno-2-17" href="#__codelineno-2-17"></a>
<a id="__codelineno-2-18" name="__codelineno-2-18" href="#__codelineno-2-18"></a><span class="sd">&quot;&quot;&quot; 获取栈的长度 &quot;&quot;&quot;</span>
<a id="__codelineno-2-19" name="__codelineno-2-19" href="#__codelineno-2-19"></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">stack</span><span class="p">)</span>
<a id="__codelineno-2-20" name="__codelineno-2-20" href="#__codelineno-2-20"></a>
<a id="__codelineno-2-21" name="__codelineno-2-21" href="#__codelineno-2-21"></a><span class="sd">&quot;&quot;&quot; 判断是否为空 &quot;&quot;&quot;</span>
<a id="__codelineno-2-22" name="__codelineno-2-22" href="#__codelineno-2-22"></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">stack</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">stack_test.go</span><pre><span></span><code><a id="__codelineno-3-1" name="__codelineno-3-1" href="#__codelineno-3-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-3-2" name="__codelineno-3-2" href="#__codelineno-3-2"></a><span class="c1">// 在 Go 中,推荐将 Slice 当作栈来使用</span>
<a id="__codelineno-3-3" name="__codelineno-3-3" href="#__codelineno-3-3"></a><span class="kd">var</span><span class="w"> </span><span class="nx">stack</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</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">/* 元素入栈 */</span>
<a id="__codelineno-3-6" name="__codelineno-3-6" href="#__codelineno-3-6"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">stack</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-3-7" name="__codelineno-3-7" href="#__codelineno-3-7"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">stack</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="p">)</span>
<a id="__codelineno-3-8" name="__codelineno-3-8" href="#__codelineno-3-8"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">stack</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="p">)</span>
<a id="__codelineno-3-9" name="__codelineno-3-9" href="#__codelineno-3-9"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">stack</span><span class="p">,</span><span class="w"> </span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-3-10" name="__codelineno-3-10" href="#__codelineno-3-10"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">stack</span><span class="p">,</span><span class="w"> </span><span class="mi">4</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">/* 访问栈顶元素 */</span>
<a id="__codelineno-3-13" name="__codelineno-3-13" href="#__codelineno-3-13"></a><span class="nx">peek</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">stack</span><span class="p">[</span><span class="nb">len</span><span class="p">(</span><span class="nx">stack</span><span class="p">)</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<a id="__codelineno-3-14" name="__codelineno-3-14" href="#__codelineno-3-14"></a>
<a id="__codelineno-3-15" name="__codelineno-3-15" href="#__codelineno-3-15"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-3-16" name="__codelineno-3-16" href="#__codelineno-3-16"></a><span class="nx">pop</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">stack</span><span class="p">[</span><span class="nb">len</span><span class="p">(</span><span class="nx">stack</span><span class="p">)</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<a id="__codelineno-3-17" name="__codelineno-3-17" href="#__codelineno-3-17"></a><span class="nx">stack</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">stack</span><span class="p">[:</span><span class="nb">len</span><span class="p">(</span><span class="nx">stack</span><span class="p">)</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<a id="__codelineno-3-18" name="__codelineno-3-18" href="#__codelineno-3-18"></a>
<a id="__codelineno-3-19" name="__codelineno-3-19" href="#__codelineno-3-19"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-3-20" name="__codelineno-3-20" href="#__codelineno-3-20"></a><span class="nx">size</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">len</span><span class="p">(</span><span class="nx">stack</span><span class="p">)</span>
<a id="__codelineno-3-21" name="__codelineno-3-21" href="#__codelineno-3-21"></a>
<a id="__codelineno-3-22" name="__codelineno-3-22" href="#__codelineno-3-22"></a><span class="cm">/* 判断是否为空 */</span>
<a id="__codelineno-3-23" name="__codelineno-3-23" href="#__codelineno-3-23"></a><span class="nx">isEmpty</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">len</span><span class="p">(</span><span class="nx">stack</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">stack.js</span><pre><span></span><code><a id="__codelineno-4-1" name="__codelineno-4-1" href="#__codelineno-4-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-4-2" name="__codelineno-4-2" href="#__codelineno-4-2"></a><span class="c1">// Javascript 没有内置的栈类,可以把 Array 当作栈来使用 </span>
<a id="__codelineno-4-3" name="__codelineno-4-3" href="#__codelineno-4-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">stack</span><span class="w"> </span><span class="o">=</span><span class="w"> </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">/* 元素入栈 */</span>
<a id="__codelineno-4-6" name="__codelineno-4-6" href="#__codelineno-4-6"></a><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-4-7" name="__codelineno-4-7" href="#__codelineno-4-7"></a><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-4-8" name="__codelineno-4-8" href="#__codelineno-4-8"></a><span class="nx">stack</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-4-9" name="__codelineno-4-9" href="#__codelineno-4-9"></a><span class="nx">stack</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-4-10" name="__codelineno-4-10" href="#__codelineno-4-10"></a><span class="nx">stack</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-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">/* 访问栈顶元素 */</span>
<a id="__codelineno-4-13" name="__codelineno-4-13" href="#__codelineno-4-13"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</span><span class="p">[</span><span class="nx">stack</span><span class="p">.</span><span class="nx">length</span><span class="o">-</span><span class="mf">1</span><span class="p">];</span>
<a id="__codelineno-4-14" name="__codelineno-4-14" href="#__codelineno-4-14"></a>
<a id="__codelineno-4-15" name="__codelineno-4-15" href="#__codelineno-4-15"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-4-16" name="__codelineno-4-16" href="#__codelineno-4-16"></a><span class="kd">const</span><span class="w"> </span><span class="nx">pop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<a id="__codelineno-4-17" name="__codelineno-4-17" href="#__codelineno-4-17"></a>
<a id="__codelineno-4-18" name="__codelineno-4-18" href="#__codelineno-4-18"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-4-19" name="__codelineno-4-19" href="#__codelineno-4-19"></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">stack</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-4-20" name="__codelineno-4-20" href="#__codelineno-4-20"></a>
<a id="__codelineno-4-21" name="__codelineno-4-21" href="#__codelineno-4-21"></a><span class="cm">/* 判断是否为空 */</span>
<a id="__codelineno-4-22" name="__codelineno-4-22" href="#__codelineno-4-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">is_empty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</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">0</span><span class="p">;</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">stack.ts</span><pre><span></span><code><a id="__codelineno-5-1" name="__codelineno-5-1" href="#__codelineno-5-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-5-2" name="__codelineno-5-2" href="#__codelineno-5-2"></a><span class="c1">// Typescript 没有内置的栈类,可以把 Array 当作栈来使用 </span>
<a id="__codelineno-5-3" name="__codelineno-5-3" href="#__codelineno-5-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">stack</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-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">/* 元素入栈 */</span>
<a id="__codelineno-5-6" name="__codelineno-5-6" href="#__codelineno-5-6"></a><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-5-7" name="__codelineno-5-7" href="#__codelineno-5-7"></a><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-5-8" name="__codelineno-5-8" href="#__codelineno-5-8"></a><span class="nx">stack</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-5-9" name="__codelineno-5-9" href="#__codelineno-5-9"></a><span class="nx">stack</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-5-10" name="__codelineno-5-10" href="#__codelineno-5-10"></a><span class="nx">stack</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-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">/* 访问栈顶元素 */</span>
<a id="__codelineno-5-13" name="__codelineno-5-13" href="#__codelineno-5-13"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</span><span class="p">[</span><span class="nx">stack</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-5-14" name="__codelineno-5-14" href="#__codelineno-5-14"></a>
<a id="__codelineno-5-15" name="__codelineno-5-15" href="#__codelineno-5-15"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-5-16" name="__codelineno-5-16" href="#__codelineno-5-16"></a><span class="kd">const</span><span class="w"> </span><span class="nx">pop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<a id="__codelineno-5-17" name="__codelineno-5-17" href="#__codelineno-5-17"></a>
<a id="__codelineno-5-18" name="__codelineno-5-18" href="#__codelineno-5-18"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-5-19" name="__codelineno-5-19" href="#__codelineno-5-19"></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">stack</span><span class="p">.</span><span class="nx">length</span><span class="p">;</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">/* 判断是否为空 */</span>
<a id="__codelineno-5-22" name="__codelineno-5-22" href="#__codelineno-5-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">is_empty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">stack</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">0</span><span class="p">;</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">stack.c</span><pre><span></span><code><a id="__codelineno-6-1" name="__codelineno-6-1" href="#__codelineno-6-1"></a>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">stack.cs</span><pre><span></span><code><a id="__codelineno-7-1" name="__codelineno-7-1" href="#__codelineno-7-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-7-2" name="__codelineno-7-2" href="#__codelineno-7-2"></a><span class="n">Stack</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">stack</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="p">();</span>
<a id="__codelineno-7-3" name="__codelineno-7-3" href="#__codelineno-7-3"></a>
<a id="__codelineno-7-4" name="__codelineno-7-4" href="#__codelineno-7-4"></a><span class="cm">/* 元素入栈 */</span>
<a id="__codelineno-7-5" name="__codelineno-7-5" href="#__codelineno-7-5"></a><span class="n">stack</span><span class="p">.</span><span class="n">Push</span><span class="p">(</span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-7-6" name="__codelineno-7-6" href="#__codelineno-7-6"></a><span class="n">stack</span><span class="p">.</span><span class="n">Push</span><span class="p">(</span><span class="m">3</span><span class="p">);</span>
<a id="__codelineno-7-7" name="__codelineno-7-7" href="#__codelineno-7-7"></a><span class="n">stack</span><span class="p">.</span><span class="n">Push</span><span class="p">(</span><span class="m">2</span><span class="p">);</span>
<a id="__codelineno-7-8" name="__codelineno-7-8" href="#__codelineno-7-8"></a><span class="n">stack</span><span class="p">.</span><span class="n">Push</span><span class="p">(</span><span class="m">5</span><span class="p">);</span>
<a id="__codelineno-7-9" name="__codelineno-7-9" href="#__codelineno-7-9"></a><span class="n">stack</span><span class="p">.</span><span class="n">Push</span><span class="p">(</span><span class="m">4</span><span class="p">);</span>
<a id="__codelineno-7-10" name="__codelineno-7-10" href="#__codelineno-7-10"></a>
<a id="__codelineno-7-11" name="__codelineno-7-11" href="#__codelineno-7-11"></a><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-7-12" name="__codelineno-7-12" href="#__codelineno-7-12"></a><span class="kt">int</span><span class="w"> </span><span class="n">peek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">Peek</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">/* 元素出栈 */</span>
<a id="__codelineno-7-15" name="__codelineno-7-15" href="#__codelineno-7-15"></a><span class="kt">int</span><span class="w"> </span><span class="n">pop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">Pop</span><span class="p">();</span>
<a id="__codelineno-7-16" name="__codelineno-7-16" href="#__codelineno-7-16"></a>
<a id="__codelineno-7-17" name="__codelineno-7-17" href="#__codelineno-7-17"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-7-18" name="__codelineno-7-18" href="#__codelineno-7-18"></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">stack</span><span class="p">.</span><span class="n">Count</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">/* 判断是否为空 */</span>
<a id="__codelineno-7-21" name="__codelineno-7-21" href="#__codelineno-7-21"></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">stack</span><span class="p">.</span><span class="n">Count</span><span class="p">()</span><span class="o">==</span><span class="m">0</span><span class="p">;</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">stack.swift</span><pre><span></span><code><a id="__codelineno-8-1" name="__codelineno-8-1" href="#__codelineno-8-1"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-8-2" name="__codelineno-8-2" href="#__codelineno-8-2"></a><span class="c1">// Swift 没有内置的栈类,可以把 Array 当作栈来使用</span>
<a id="__codelineno-8-3" name="__codelineno-8-3" href="#__codelineno-8-3"></a><span class="kd">var</span> <span class="nv">stack</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-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">/* 元素入栈 */</span>
<a id="__codelineno-8-6" name="__codelineno-8-6" href="#__codelineno-8-6"></a><span class="n">stack</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-8-7" name="__codelineno-8-7" href="#__codelineno-8-7"></a><span class="n">stack</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span>
<a id="__codelineno-8-8" name="__codelineno-8-8" href="#__codelineno-8-8"></a><span class="n">stack</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span>
<a id="__codelineno-8-9" name="__codelineno-8-9" href="#__codelineno-8-9"></a><span class="n">stack</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-8-10" name="__codelineno-8-10" href="#__codelineno-8-10"></a><span class="n">stack</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-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">/* 访问栈顶元素 */</span>
<a id="__codelineno-8-13" name="__codelineno-8-13" href="#__codelineno-8-13"></a><span class="kd">let</span> <span class="nv">peek</span> <span class="p">=</span> <span class="n">stack</span><span class="p">.</span><span class="bp">last</span><span class="p">!</span>
<a id="__codelineno-8-14" name="__codelineno-8-14" href="#__codelineno-8-14"></a>
<a id="__codelineno-8-15" name="__codelineno-8-15" href="#__codelineno-8-15"></a><span class="cm">/* 元素出栈 */</span>
<a id="__codelineno-8-16" name="__codelineno-8-16" href="#__codelineno-8-16"></a><span class="kd">let</span> <span class="nv">pop</span> <span class="p">=</span> <span class="n">stack</span><span class="p">.</span><span class="bp">removeLast</span><span class="p">()</span>
<a id="__codelineno-8-17" name="__codelineno-8-17" href="#__codelineno-8-17"></a>
<a id="__codelineno-8-18" name="__codelineno-8-18" href="#__codelineno-8-18"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-8-19" name="__codelineno-8-19" href="#__codelineno-8-19"></a><span class="kd">let</span> <span class="nv">size</span> <span class="p">=</span> <span class="n">stack</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-8-20" name="__codelineno-8-20" href="#__codelineno-8-20"></a>
<a id="__codelineno-8-21" name="__codelineno-8-21" href="#__codelineno-8-21"></a><span class="cm">/* 判断是否为空 */</span>
<a id="__codelineno-8-22" name="__codelineno-8-22" href="#__codelineno-8-22"></a><span class="kd">let</span> <span class="nv">isEmpty</span> <span class="p">=</span> <span class="n">stack</span><span class="p">.</span><span class="bp">isEmpty</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">stack.zig</span><pre><span></span><code><a id="__codelineno-9-1" name="__codelineno-9-1" href="#__codelineno-9-1"></a>
</code></pre></div>
</div>
</div>
</div>
<h2 id="512">5.1.2. &nbsp; 栈的实现<a class="headerlink" href="#512" title="Permanent link">&para;</a></h2>
<p>为了更加清晰地了解栈的运行机制,接下来我们来自己动手实现一个栈类。</p>
<p>栈规定元素是先入后出的,因此我们只能在栈顶添加或删除元素。然而,数组或链表都可以在任意位置添加删除元素,因此 <strong>栈可被看作是一种受约束的数组或链表</strong>。换言之,我们可以“屏蔽”数组或链表的部分无关操作,使之对外的表现逻辑符合栈的规定即可。</p>
<h3 id="_1">基于链表的实现<a class="headerlink" href="#_1" title="Permanent link">&para;</a></h3>
<p>使用「链表」实现栈时,将链表的头结点看作栈顶,将尾结点看作栈底。</p>
<p>对于入栈操作,将元素插入到链表头部即可,这种结点添加方式被称为“头插法”。而对于出栈操作,则将头结点从链表中删除即可。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="2:3"><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" /><div class="tabbed-labels"><label for="__tabbed_2_1">LinkedListStack</label><label for="__tabbed_2_2">push()</label><label for="__tabbed_2_3">pop()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><img alt="基于链表实现栈的入栈出栈操作" src="../stack.assets/linkedlist_stack.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_stack_push" src="../stack.assets/linkedlist_stack_push.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_stack_pop" src="../stack.assets/linkedlist_stack_pop.png" /></p>
</div>
</div>
</div>
<p>以下是基于链表实现栈的示例代码。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="3:10"><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" /><div class="tabbed-labels"><label for="__tabbed_3_1">Java</label><label for="__tabbed_3_2">C++</label><label for="__tabbed_3_3">Python</label><label for="__tabbed_3_4">Go</label><label for="__tabbed_3_5">JavaScript</label><label for="__tabbed_3_6">TypeScript</label><label for="__tabbed_3_7">C</label><label for="__tabbed_3_8">C#</label><label for="__tabbed_3_9">Swift</label><label for="__tabbed_3_10">Zig</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.java</span><pre><span></span><code><a id="__codelineno-10-1" name="__codelineno-10-1" href="#__codelineno-10-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-10-2" name="__codelineno-10-2" href="#__codelineno-10-2"></a><span class="kd">class</span> <span class="nc">LinkedListStack</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-3" name="__codelineno-10-3" href="#__codelineno-10-3"></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">stackPeek</span><span class="p">;</span><span class="w"> </span><span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-10-4" name="__codelineno-10-4" href="#__codelineno-10-4"></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">stkSize</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">// 栈的长度</span>
<a id="__codelineno-10-5" name="__codelineno-10-5" href="#__codelineno-10-5"></a>
<a id="__codelineno-10-6" name="__codelineno-10-6" href="#__codelineno-10-6"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">LinkedListStack</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-7" name="__codelineno-10-7" href="#__codelineno-10-7"></a><span class="w"> </span><span class="n">stackPeek</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-10-8" name="__codelineno-10-8" href="#__codelineno-10-8"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-9" name="__codelineno-10-9" href="#__codelineno-10-9"></a>
<a id="__codelineno-10-10" name="__codelineno-10-10" href="#__codelineno-10-10"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-10-11" name="__codelineno-10-11" href="#__codelineno-10-11"></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-10-12" name="__codelineno-10-12" href="#__codelineno-10-12"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stkSize</span><span class="p">;</span>
<a id="__codelineno-10-13" name="__codelineno-10-13" href="#__codelineno-10-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-14" name="__codelineno-10-14" href="#__codelineno-10-14"></a>
<a id="__codelineno-10-15" name="__codelineno-10-15" href="#__codelineno-10-15"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-10-16" name="__codelineno-10-16" href="#__codelineno-10-16"></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-10-17" name="__codelineno-10-17" href="#__codelineno-10-17"></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-10-18" name="__codelineno-10-18" href="#__codelineno-10-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-19" name="__codelineno-10-19" href="#__codelineno-10-19"></a>
<a id="__codelineno-10-20" name="__codelineno-10-20" href="#__codelineno-10-20"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-10-21" name="__codelineno-10-21" href="#__codelineno-10-21"></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">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="p">{</span>
<a id="__codelineno-10-22" name="__codelineno-10-22" href="#__codelineno-10-22"></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-10-23" name="__codelineno-10-23" href="#__codelineno-10-23"></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">stackPeek</span><span class="p">;</span>
<a id="__codelineno-10-24" name="__codelineno-10-24" href="#__codelineno-10-24"></a><span class="w"> </span><span class="n">stackPeek</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-10-25" name="__codelineno-10-25" href="#__codelineno-10-25"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-10-26" name="__codelineno-10-26" href="#__codelineno-10-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-27" name="__codelineno-10-27" href="#__codelineno-10-27"></a>
<a id="__codelineno-10-28" name="__codelineno-10-28" href="#__codelineno-10-28"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-10-29" name="__codelineno-10-29" href="#__codelineno-10-29"></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">pop</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-30" name="__codelineno-10-30" href="#__codelineno-10-30"></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">peek</span><span class="p">();</span>
<a id="__codelineno-10-31" name="__codelineno-10-31" href="#__codelineno-10-31"></a><span class="w"> </span><span class="n">stackPeek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stackPeek</span><span class="p">.</span><span class="na">next</span><span class="p">;</span>
<a id="__codelineno-10-32" name="__codelineno-10-32" href="#__codelineno-10-32"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-10-33" name="__codelineno-10-33" href="#__codelineno-10-33"></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-10-34" name="__codelineno-10-34" href="#__codelineno-10-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-35" name="__codelineno-10-35" href="#__codelineno-10-35"></a>
<a id="__codelineno-10-36" name="__codelineno-10-36" href="#__codelineno-10-36"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-10-37" name="__codelineno-10-37" href="#__codelineno-10-37"></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">peek</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-38" name="__codelineno-10-38" href="#__codelineno-10-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </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-10-39" name="__codelineno-10-39" href="#__codelineno-10-39"></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">EmptyStackException</span><span class="p">();</span>
<a id="__codelineno-10-40" name="__codelineno-10-40" href="#__codelineno-10-40"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stackPeek</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-10-41" name="__codelineno-10-41" href="#__codelineno-10-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-42" name="__codelineno-10-42" href="#__codelineno-10-42"></a>
<a id="__codelineno-10-43" name="__codelineno-10-43" href="#__codelineno-10-43"></a><span class="w"> </span><span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-10-44" name="__codelineno-10-44" href="#__codelineno-10-44"></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-10-45" name="__codelineno-10-45" href="#__codelineno-10-45"></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">stackPeek</span><span class="p">;</span>
<a id="__codelineno-10-46" name="__codelineno-10-46" href="#__codelineno-10-46"></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-10-47" name="__codelineno-10-47" href="#__codelineno-10-47"></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="n">res</span><span class="p">.</span><span class="na">length</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="n">i</span><span class="w"> </span><span class="o">&gt;=</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="o">--</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-48" name="__codelineno-10-48" href="#__codelineno-10-48"></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-10-49" name="__codelineno-10-49" href="#__codelineno-10-49"></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-10-50" name="__codelineno-10-50" href="#__codelineno-10-50"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-51" name="__codelineno-10-51" href="#__codelineno-10-51"></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-10-52" name="__codelineno-10-52" href="#__codelineno-10-52"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-53" name="__codelineno-10-53" href="#__codelineno-10-53"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.cpp</span><pre><span></span><code><a id="__codelineno-11-1" name="__codelineno-11-1" href="#__codelineno-11-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-11-2" name="__codelineno-11-2" href="#__codelineno-11-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListStack</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-3" name="__codelineno-11-3" href="#__codelineno-11-3"></a><span class="k">private</span><span class="o">:</span>
<a id="__codelineno-11-4" name="__codelineno-11-4" href="#__codelineno-11-4"></a><span class="w"> </span><span class="n">ListNode</span><span class="o">*</span><span class="w"> </span><span class="n">stackTop</span><span class="p">;</span><span class="w"> </span><span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-11-5" name="__codelineno-11-5" href="#__codelineno-11-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">stkSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 栈的长度</span>
<a id="__codelineno-11-6" name="__codelineno-11-6" href="#__codelineno-11-6"></a>
<a id="__codelineno-11-7" name="__codelineno-11-7" href="#__codelineno-11-7"></a><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-11-8" name="__codelineno-11-8" href="#__codelineno-11-8"></a><span class="w"> </span><span class="n">LinkedListStack</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-9" name="__codelineno-11-9" href="#__codelineno-11-9"></a><span class="w"> </span><span class="n">stackTop</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-11-10" name="__codelineno-11-10" href="#__codelineno-11-10"></a><span class="w"> </span><span class="n">stkSize</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-11-11" name="__codelineno-11-11" href="#__codelineno-11-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-12" name="__codelineno-11-12" href="#__codelineno-11-12"></a>
<a id="__codelineno-11-13" name="__codelineno-11-13" href="#__codelineno-11-13"></a><span class="w"> </span><span class="o">~</span><span class="n">LinkedListStack</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-14" name="__codelineno-11-14" href="#__codelineno-11-14"></a><span class="w"> </span><span class="c1">// 遍历链表删除结点,释放内存</span>
<a id="__codelineno-11-15" name="__codelineno-11-15" href="#__codelineno-11-15"></a><span class="w"> </span><span class="n">freeMemoryLinkedList</span><span class="p">(</span><span class="n">stackTop</span><span class="p">);</span>
<a id="__codelineno-11-16" name="__codelineno-11-16" href="#__codelineno-11-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-17" name="__codelineno-11-17" href="#__codelineno-11-17"></a>
<a id="__codelineno-11-18" name="__codelineno-11-18" href="#__codelineno-11-18"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-11-19" name="__codelineno-11-19" href="#__codelineno-11-19"></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-11-20" name="__codelineno-11-20" href="#__codelineno-11-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stkSize</span><span class="p">;</span>
<a id="__codelineno-11-21" name="__codelineno-11-21" href="#__codelineno-11-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-22" name="__codelineno-11-22" href="#__codelineno-11-22"></a>
<a id="__codelineno-11-23" name="__codelineno-11-23" href="#__codelineno-11-23"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-11-24" name="__codelineno-11-24" href="#__codelineno-11-24"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">empty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-25" name="__codelineno-11-25" href="#__codelineno-11-25"></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-11-26" name="__codelineno-11-26" href="#__codelineno-11-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-27" name="__codelineno-11-27" href="#__codelineno-11-27"></a>
<a id="__codelineno-11-28" name="__codelineno-11-28" href="#__codelineno-11-28"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-11-29" name="__codelineno-11-29" href="#__codelineno-11-29"></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="p">{</span>
<a id="__codelineno-11-30" name="__codelineno-11-30" href="#__codelineno-11-30"></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="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-11-31" name="__codelineno-11-31" href="#__codelineno-11-31"></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">stackTop</span><span class="p">;</span>
<a id="__codelineno-11-32" name="__codelineno-11-32" href="#__codelineno-11-32"></a><span class="w"> </span><span class="n">stackTop</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-11-33" name="__codelineno-11-33" href="#__codelineno-11-33"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-11-34" name="__codelineno-11-34" href="#__codelineno-11-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-35" name="__codelineno-11-35" href="#__codelineno-11-35"></a>
<a id="__codelineno-11-36" name="__codelineno-11-36" href="#__codelineno-11-36"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-11-37" name="__codelineno-11-37" href="#__codelineno-11-37"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pop</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-38" name="__codelineno-11-38" href="#__codelineno-11-38"></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">top</span><span class="p">();</span>
<a id="__codelineno-11-39" name="__codelineno-11-39" href="#__codelineno-11-39"></a><span class="w"> </span><span class="n">ListNode</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">stackTop</span><span class="p">;</span>
<a id="__codelineno-11-40" name="__codelineno-11-40" href="#__codelineno-11-40"></a><span class="w"> </span><span class="n">stackTop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stackTop</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-11-41" name="__codelineno-11-41" href="#__codelineno-11-41"></a><span class="w"> </span><span class="c1">// 释放内存</span>
<a id="__codelineno-11-42" name="__codelineno-11-42" href="#__codelineno-11-42"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">tmp</span><span class="p">;</span>
<a id="__codelineno-11-43" name="__codelineno-11-43" href="#__codelineno-11-43"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-11-44" name="__codelineno-11-44" href="#__codelineno-11-44"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-45" name="__codelineno-11-45" href="#__codelineno-11-45"></a>
<a id="__codelineno-11-46" name="__codelineno-11-46" href="#__codelineno-11-46"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-11-47" name="__codelineno-11-47" href="#__codelineno-11-47"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">top</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-48" name="__codelineno-11-48" href="#__codelineno-11-48"></a><span class="w"> </span><span class="k">if</span><span class="w"> </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-11-49" name="__codelineno-11-49" href="#__codelineno-11-49"></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;栈为空&quot;</span><span class="p">);</span>
<a id="__codelineno-11-50" name="__codelineno-11-50" href="#__codelineno-11-50"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stackTop</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-11-51" name="__codelineno-11-51" href="#__codelineno-11-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-52" name="__codelineno-11-52" href="#__codelineno-11-52"></a>
<a id="__codelineno-11-53" name="__codelineno-11-53" href="#__codelineno-11-53"></a><span class="w"> </span><span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-11-54" name="__codelineno-11-54" href="#__codelineno-11-54"></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-11-55" name="__codelineno-11-55" href="#__codelineno-11-55"></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">stackTop</span><span class="p">;</span>
<a id="__codelineno-11-56" name="__codelineno-11-56" href="#__codelineno-11-56"></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-11-57" name="__codelineno-11-57" href="#__codelineno-11-57"></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="n">res</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">1</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&gt;=</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="o">--</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-58" name="__codelineno-11-58" href="#__codelineno-11-58"></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-11-59" name="__codelineno-11-59" href="#__codelineno-11-59"></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-11-60" name="__codelineno-11-60" href="#__codelineno-11-60"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-61" name="__codelineno-11-61" href="#__codelineno-11-61"></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-11-62" name="__codelineno-11-62" href="#__codelineno-11-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-63" name="__codelineno-11-63" href="#__codelineno-11-63"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.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">LinkedListStack</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; 基于链表实现的栈 &quot;&quot;&quot;</span>
<a id="__codelineno-12-3" name="__codelineno-12-3" href="#__codelineno-12-3"></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-12-4" name="__codelineno-12-4" href="#__codelineno-12-4"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 构造方法 &quot;&quot;&quot;</span>
<a id="__codelineno-12-5" name="__codelineno-12-5" href="#__codelineno-12-5"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</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>
<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">__size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-12-7" name="__codelineno-12-7" href="#__codelineno-12-7"></a>
<a id="__codelineno-12-8" name="__codelineno-12-8" href="#__codelineno-12-8"></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-12-9" name="__codelineno-12-9" href="#__codelineno-12-9"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 获取栈的长度 &quot;&quot;&quot;</span>
<a id="__codelineno-12-10" name="__codelineno-12-10" href="#__codelineno-12-10"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a>
<a id="__codelineno-12-12" name="__codelineno-12-12" href="#__codelineno-12-12"></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-12-13" name="__codelineno-12-13" href="#__codelineno-12-13"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 判断栈是否为空 &quot;&quot;&quot;</span>
<a id="__codelineno-12-14" name="__codelineno-12-14" href="#__codelineno-12-14"></a> <span class="k">return</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span>
<a id="__codelineno-12-15" name="__codelineno-12-15" href="#__codelineno-12-15"></a>
<a id="__codelineno-12-16" name="__codelineno-12-16" href="#__codelineno-12-16"></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">val</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-17" name="__codelineno-12-17" href="#__codelineno-12-17"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 入栈 &quot;&quot;&quot;</span>
<a id="__codelineno-12-18" name="__codelineno-12-18" href="#__codelineno-12-18"></a> <span class="n">node</span> <span class="o">=</span> <span class="n">ListNode</span><span class="p">(</span><span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-19" name="__codelineno-12-19" href="#__codelineno-12-19"></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">__peek</span>
<a id="__codelineno-12-20" name="__codelineno-12-20" href="#__codelineno-12-20"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-21" name="__codelineno-12-21" href="#__codelineno-12-21"></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-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">pop</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-12-24" name="__codelineno-12-24" href="#__codelineno-12-24"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 出栈 &quot;&quot;&quot;</span>
<a id="__codelineno-12-25" name="__codelineno-12-25" href="#__codelineno-12-25"></a> <span class="n">num</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">peek</span><span class="p">()</span>
<a id="__codelineno-12-26" name="__codelineno-12-26" href="#__codelineno-12-26"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span><span class="o">.</span><span class="n">next</span>
<a id="__codelineno-12-27" name="__codelineno-12-27" href="#__codelineno-12-27"></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-12-28" name="__codelineno-12-28" href="#__codelineno-12-28"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-12-29" name="__codelineno-12-29" href="#__codelineno-12-29"></a>
<a id="__codelineno-12-30" name="__codelineno-12-30" href="#__codelineno-12-30"></a> <span class="k">def</span> <span class="nf">peek</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-12-31" name="__codelineno-12-31" href="#__codelineno-12-31"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 访问栈顶元素 &quot;&quot;&quot;</span>
<a id="__codelineno-12-32" name="__codelineno-12-32" href="#__codelineno-12-32"></a> <span class="c1"># 判空处理</span>
<a id="__codelineno-12-33" name="__codelineno-12-33" href="#__codelineno-12-33"></a> <span class="k">if</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span><span class="p">:</span> <span class="k">return</span> <span class="kc">None</span>
<a id="__codelineno-12-34" name="__codelineno-12-34" href="#__codelineno-12-34"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-35" name="__codelineno-12-35" href="#__codelineno-12-35"></a>
<a id="__codelineno-12-36" name="__codelineno-12-36" href="#__codelineno-12-36"></a> <span class="k">def</span> <span class="nf">to_list</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-12-37" name="__codelineno-12-37" href="#__codelineno-12-37"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 转化为列表用于打印 &quot;&quot;&quot;</span>
<a id="__codelineno-12-38" name="__codelineno-12-38" href="#__codelineno-12-38"></a> <span class="n">arr</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>
<a id="__codelineno-12-39" name="__codelineno-12-39" href="#__codelineno-12-39"></a> <span class="n">node</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">__peek</span>
<a id="__codelineno-12-40" name="__codelineno-12-40" href="#__codelineno-12-40"></a> <span class="k">while</span> <span class="n">node</span><span class="p">:</span>
<a id="__codelineno-12-41" name="__codelineno-12-41" href="#__codelineno-12-41"></a> <span class="n">arr</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">node</span><span class="o">.</span><span class="n">val</span><span class="p">)</span>
<a id="__codelineno-12-42" name="__codelineno-12-42" href="#__codelineno-12-42"></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-12-43" name="__codelineno-12-43" href="#__codelineno-12-43"></a> <span class="n">arr</span><span class="o">.</span><span class="n">reverse</span><span class="p">()</span>
<a id="__codelineno-12-44" name="__codelineno-12-44" href="#__codelineno-12-44"></a> <span class="k">return</span> <span class="n">arr</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.go</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="kd">type</span><span class="w"> </span><span class="nx">linkedListStack</span><span class="w"> </span><span class="kd">struct</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="c1">// 使用内置包 list 来实现栈</span>
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></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-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a><span class="p">}</span>
<a id="__codelineno-13-6" name="__codelineno-13-6" href="#__codelineno-13-6"></a>
<a id="__codelineno-13-7" name="__codelineno-13-7" href="#__codelineno-13-7"></a><span class="cm">/* 初始化栈 */</span>
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a><span class="kd">func</span><span class="w"> </span><span class="nx">newLinkedListStack</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListStack</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">&amp;</span><span class="nx">linkedListStack</span><span class="p">{</span>
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></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-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a><span class="p">}</span>
<a id="__codelineno-13-13" name="__codelineno-13-13" href="#__codelineno-13-13"></a>
<a id="__codelineno-13-14" name="__codelineno-13-14" href="#__codelineno-13-14"></a><span class="cm">/* 入栈 */</span>
<a id="__codelineno-13-15" name="__codelineno-13-15" href="#__codelineno-13-15"></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">linkedListStack</span><span class="p">)</span><span class="w"> </span><span class="nx">push</span><span class="p">(</span><span class="nx">value</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-13-16" name="__codelineno-13-16" href="#__codelineno-13-16"></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">PushBack</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span>
<a id="__codelineno-13-17" name="__codelineno-13-17" href="#__codelineno-13-17"></a><span class="p">}</span>
<a id="__codelineno-13-18" name="__codelineno-13-18" href="#__codelineno-13-18"></a>
<a id="__codelineno-13-19" name="__codelineno-13-19" href="#__codelineno-13-19"></a><span class="cm">/* 出栈 */</span>
<a id="__codelineno-13-20" name="__codelineno-13-20" href="#__codelineno-13-20"></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">linkedListStack</span><span class="p">)</span><span class="w"> </span><span class="nx">pop</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-13-21" name="__codelineno-13-21" href="#__codelineno-13-21"></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-13-22" name="__codelineno-13-22" href="#__codelineno-13-22"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-23" name="__codelineno-13-23" href="#__codelineno-13-23"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-24" name="__codelineno-13-24" href="#__codelineno-13-24"></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-13-25" name="__codelineno-13-25" href="#__codelineno-13-25"></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-13-26" name="__codelineno-13-26" href="#__codelineno-13-26"></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-13-27" name="__codelineno-13-27" href="#__codelineno-13-27"></a><span class="p">}</span>
<a id="__codelineno-13-28" name="__codelineno-13-28" href="#__codelineno-13-28"></a>
<a id="__codelineno-13-29" name="__codelineno-13-29" href="#__codelineno-13-29"></a><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-13-30" name="__codelineno-13-30" href="#__codelineno-13-30"></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">linkedListStack</span><span class="p">)</span><span class="w"> </span><span class="nx">peek</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-13-31" name="__codelineno-13-31" href="#__codelineno-13-31"></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-13-32" name="__codelineno-13-32" href="#__codelineno-13-32"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-33" name="__codelineno-13-33" href="#__codelineno-13-33"></a><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="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-13-35" name="__codelineno-13-35" href="#__codelineno-13-35"></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-13-36" name="__codelineno-13-36" href="#__codelineno-13-36"></a><span class="p">}</span>
<a id="__codelineno-13-37" name="__codelineno-13-37" href="#__codelineno-13-37"></a>
<a id="__codelineno-13-38" name="__codelineno-13-38" href="#__codelineno-13-38"></a><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-13-39" name="__codelineno-13-39" href="#__codelineno-13-39"></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">linkedListStack</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-13-40" name="__codelineno-13-40" href="#__codelineno-13-40"></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-13-41" name="__codelineno-13-41" href="#__codelineno-13-41"></a><span class="p">}</span>
<a id="__codelineno-13-42" name="__codelineno-13-42" href="#__codelineno-13-42"></a>
<a id="__codelineno-13-43" name="__codelineno-13-43" href="#__codelineno-13-43"></a><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-13-44" name="__codelineno-13-44" href="#__codelineno-13-44"></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">linkedListStack</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-13-45" name="__codelineno-13-45" href="#__codelineno-13-45"></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-13-46" name="__codelineno-13-46" href="#__codelineno-13-46"></a><span class="p">}</span>
<a id="__codelineno-13-47" name="__codelineno-13-47" href="#__codelineno-13-47"></a>
<a id="__codelineno-13-48" name="__codelineno-13-48" href="#__codelineno-13-48"></a><span class="cm">/* 获取 List 用于打印 */</span>
<a id="__codelineno-13-49" name="__codelineno-13-49" href="#__codelineno-13-49"></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">linkedListStack</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-13-50" name="__codelineno-13-50" href="#__codelineno-13-50"></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-13-51" name="__codelineno-13-51" href="#__codelineno-13-51"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.js</span><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListStack</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="err">#</span><span class="nx">stackPeek</span><span class="p">;</span><span class="w"> </span><span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="w"> </span><span class="err">#</span><span class="nx">stkSize</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="c1">// 栈的长度</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></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-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stackPeek</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-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a>
<a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a><span class="w"> </span><span class="nx">get</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-12" name="__codelineno-14-12" href="#__codelineno-14-12"></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">stkSize</span><span class="p">;</span>
<a id="__codelineno-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a>
<a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></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-14-17" name="__codelineno-14-17" href="#__codelineno-14-17"></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">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-14-18" name="__codelineno-14-18" href="#__codelineno-14-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-19" name="__codelineno-14-19" href="#__codelineno-14-19"></a>
<a id="__codelineno-14-20" name="__codelineno-14-20" href="#__codelineno-14-20"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-14-21" name="__codelineno-14-21" href="#__codelineno-14-21"></a><span class="w"> </span><span class="nx">push</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-14-22" name="__codelineno-14-22" href="#__codelineno-14-22"></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">num</span><span class="p">);</span>
<a id="__codelineno-14-23" name="__codelineno-14-23" href="#__codelineno-14-23"></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">stackPeek</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">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stackPeek</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-14-25" name="__codelineno-14-25" href="#__codelineno-14-25"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stkSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-14-26" name="__codelineno-14-26" href="#__codelineno-14-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-27" name="__codelineno-14-27" href="#__codelineno-14-27"></a>
<a id="__codelineno-14-28" name="__codelineno-14-28" href="#__codelineno-14-28"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-14-29" name="__codelineno-14-29" href="#__codelineno-14-29"></a><span class="w"> </span><span class="nx">pop</span><span class="p">()</span><span class="w"> </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="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">peek</span><span class="p">();</span>
<a id="__codelineno-14-31" name="__codelineno-14-31" href="#__codelineno-14-31"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stackPeek</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">stackPeek</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-14-32" name="__codelineno-14-32" href="#__codelineno-14-32"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stkSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-14-33" name="__codelineno-14-33" href="#__codelineno-14-33"></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-14-34" name="__codelineno-14-34" href="#__codelineno-14-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-35" name="__codelineno-14-35" href="#__codelineno-14-35"></a>
<a id="__codelineno-14-36" name="__codelineno-14-36" href="#__codelineno-14-36"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-14-37" name="__codelineno-14-37" href="#__codelineno-14-37"></a><span class="w"> </span><span class="nx">peek</span><span class="p">()</span><span class="w"> </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="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stackPeek</span><span class="p">)</span>
<a id="__codelineno-14-39" name="__codelineno-14-39" href="#__codelineno-14-39"></a><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="s2">&quot;栈为空&quot;</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="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stackPeek</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-14-41" name="__codelineno-14-41" href="#__codelineno-14-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-42" name="__codelineno-14-42" href="#__codelineno-14-42"></a>
<a id="__codelineno-14-43" name="__codelineno-14-43" href="#__codelineno-14-43"></a><span class="w"> </span><span class="cm">/* 将链表转化为 Array 并返回 */</span>
<a id="__codelineno-14-44" name="__codelineno-14-44" href="#__codelineno-14-44"></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-14-45" name="__codelineno-14-45" href="#__codelineno-14-45"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">node</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">stackPeek</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="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="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">size</span><span class="p">);</span>
<a id="__codelineno-14-47" name="__codelineno-14-47" href="#__codelineno-14-47"></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="nx">res</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><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&gt;=</span><span class="w"> </span><span class="mf">0</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="p">{</span>
<a id="__codelineno-14-48" name="__codelineno-14-48" href="#__codelineno-14-48"></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="nx">node</span><span class="p">.</span><span class="nx">val</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="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">next</span><span class="p">;</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="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</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><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.ts</span><pre><span></span><code><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-15-2" name="__codelineno-15-2" href="#__codelineno-15-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListStack</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">private</span><span class="w"> </span><span class="nx">stackPeek</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="kc">null</span><span class="p">;</span><span class="w"> </span><span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-15-4" name="__codelineno-15-4" href="#__codelineno-15-4"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">stkSize</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="mf">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 栈的长度</span>
<a id="__codelineno-15-5" name="__codelineno-15-5" href="#__codelineno-15-5"></a>
<a id="__codelineno-15-6" name="__codelineno-15-6" href="#__codelineno-15-6"></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-15-7" name="__codelineno-15-7" href="#__codelineno-15-7"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stackPeek</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-15-8" name="__codelineno-15-8" href="#__codelineno-15-8"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-9" name="__codelineno-15-9" href="#__codelineno-15-9"></a>
<a id="__codelineno-15-10" name="__codelineno-15-10" href="#__codelineno-15-10"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-15-11" name="__codelineno-15-11" href="#__codelineno-15-11"></a><span class="w"> </span><span class="nx">get</span><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-15-12" name="__codelineno-15-12" href="#__codelineno-15-12"></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">stkSize</span><span class="p">;</span>
<a id="__codelineno-15-13" name="__codelineno-15-13" href="#__codelineno-15-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-14" name="__codelineno-15-14" href="#__codelineno-15-14"></a>
<a id="__codelineno-15-15" name="__codelineno-15-15" href="#__codelineno-15-15"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-15-16" name="__codelineno-15-16" href="#__codelineno-15-16"></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-15-17" name="__codelineno-15-17" href="#__codelineno-15-17"></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">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-15-18" name="__codelineno-15-18" href="#__codelineno-15-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-19" name="__codelineno-15-19" href="#__codelineno-15-19"></a>
<a id="__codelineno-15-20" name="__codelineno-15-20" href="#__codelineno-15-20"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-15-21" name="__codelineno-15-21" href="#__codelineno-15-21"></a><span class="w"> </span><span class="nx">push</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-15-22" name="__codelineno-15-22" href="#__codelineno-15-22"></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">num</span><span class="p">);</span>
<a id="__codelineno-15-23" name="__codelineno-15-23" href="#__codelineno-15-23"></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">stackPeek</span><span class="p">;</span>
<a id="__codelineno-15-24" name="__codelineno-15-24" href="#__codelineno-15-24"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stackPeek</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-15-25" name="__codelineno-15-25" href="#__codelineno-15-25"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stkSize</span><span class="o">++</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="p">}</span>
<a id="__codelineno-15-27" name="__codelineno-15-27" href="#__codelineno-15-27"></a>
<a id="__codelineno-15-28" name="__codelineno-15-28" href="#__codelineno-15-28"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-15-29" name="__codelineno-15-29" href="#__codelineno-15-29"></a><span class="w"> </span><span class="nx">pop</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-15-30" name="__codelineno-15-30" href="#__codelineno-15-30"></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">peek</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">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="k">this</span><span class="p">.</span><span class="nx">stackPeek</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;栈为空&#39;</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="k">this</span><span class="p">.</span><span class="nx">stackPeek</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">stackPeek</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-15-33" name="__codelineno-15-33" href="#__codelineno-15-33"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stkSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-15-34" name="__codelineno-15-34" href="#__codelineno-15-34"></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-15-35" name="__codelineno-15-35" href="#__codelineno-15-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-36" name="__codelineno-15-36" href="#__codelineno-15-36"></a>
<a id="__codelineno-15-37" name="__codelineno-15-37" href="#__codelineno-15-37"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-15-38" name="__codelineno-15-38" href="#__codelineno-15-38"></a><span class="w"> </span><span class="nx">peek</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-15-39" name="__codelineno-15-39" href="#__codelineno-15-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="o">!</span><span class="k">this</span><span class="p">.</span><span class="nx">stackPeek</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;栈为空&#39;</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="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stackPeek</span><span class="p">.</span><span class="nx">val</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>
<a id="__codelineno-15-43" name="__codelineno-15-43" href="#__codelineno-15-43"></a><span class="w"> </span><span class="cm">/* 将链表转化为 Array 并返回 */</span>
<a id="__codelineno-15-44" name="__codelineno-15-44" href="#__codelineno-15-44"></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-15-45" name="__codelineno-15-45" href="#__codelineno-15-45"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">node</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">stackPeek</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="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="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="o">&lt;</span><span class="kt">number</span><span class="o">&gt;</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">size</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="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="nx">res</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><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&gt;=</span><span class="w"> </span><span class="mf">0</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="p">{</span>
<a id="__codelineno-15-48" name="__codelineno-15-48" href="#__codelineno-15-48"></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="nx">node</span><span class="o">!</span><span class="p">.</span><span class="nx">val</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="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="o">!</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-15-50" name="__codelineno-15-50" href="#__codelineno-15-50"></a><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="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</span>
<a id="__codelineno-15-52" name="__codelineno-15-52" href="#__codelineno-15-52"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-53" name="__codelineno-15-53" href="#__codelineno-15-53"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.c</span><pre><span></span><code><a id="__codelineno-16-1" name="__codelineno-16-1" href="#__codelineno-16-1"></a><span class="p">[</span><span class="n">class</span><span class="p">]{</span><span class="n">linkedListStack</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 class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.cs</span><pre><span></span><code><a id="__codelineno-17-1" name="__codelineno-17-1" href="#__codelineno-17-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-17-2" name="__codelineno-17-2" href="#__codelineno-17-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListStack</span>
<a id="__codelineno-17-3" name="__codelineno-17-3" href="#__codelineno-17-3"></a><span class="p">{</span>
<a id="__codelineno-17-4" name="__codelineno-17-4" href="#__codelineno-17-4"></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">stackPeek</span><span class="p">;</span><span class="w"> </span><span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-17-5" name="__codelineno-17-5" href="#__codelineno-17-5"></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">stkSize</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">// 栈的长度</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="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">LinkedListStack</span><span class="p">()</span>
<a id="__codelineno-17-8" name="__codelineno-17-8" href="#__codelineno-17-8"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-9" name="__codelineno-17-9" href="#__codelineno-17-9"></a><span class="w"> </span><span class="n">stackPeek</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-17-10" name="__codelineno-17-10" href="#__codelineno-17-10"></a><span class="w"> </span><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="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-17-13" name="__codelineno-17-13" href="#__codelineno-17-13"></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>
<a id="__codelineno-17-14" name="__codelineno-17-14" href="#__codelineno-17-14"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-15" name="__codelineno-17-15" href="#__codelineno-17-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stkSize</span><span class="p">;</span>
<a id="__codelineno-17-16" name="__codelineno-17-16" href="#__codelineno-17-16"></a><span class="w"> </span><span class="p">}</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="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-17-19" name="__codelineno-17-19" href="#__codelineno-17-19"></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>
<a id="__codelineno-17-20" name="__codelineno-17-20" href="#__codelineno-17-20"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-21" name="__codelineno-17-21" href="#__codelineno-17-21"></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-17-22" name="__codelineno-17-22" href="#__codelineno-17-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-23" name="__codelineno-17-23" href="#__codelineno-17-23"></a>
<a id="__codelineno-17-24" name="__codelineno-17-24" href="#__codelineno-17-24"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-17-25" name="__codelineno-17-25" href="#__codelineno-17-25"></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">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span>
<a id="__codelineno-17-26" name="__codelineno-17-26" href="#__codelineno-17-26"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-27" name="__codelineno-17-27" href="#__codelineno-17-27"></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-17-28" name="__codelineno-17-28" href="#__codelineno-17-28"></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">stackPeek</span><span class="p">;</span>
<a id="__codelineno-17-29" name="__codelineno-17-29" href="#__codelineno-17-29"></a><span class="w"> </span><span class="n">stackPeek</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-17-30" name="__codelineno-17-30" href="#__codelineno-17-30"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-17-31" name="__codelineno-17-31" href="#__codelineno-17-31"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-32" name="__codelineno-17-32" href="#__codelineno-17-32"></a>
<a id="__codelineno-17-33" name="__codelineno-17-33" href="#__codelineno-17-33"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-17-34" name="__codelineno-17-34" href="#__codelineno-17-34"></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">pop</span><span class="p">()</span>
<a id="__codelineno-17-35" name="__codelineno-17-35" href="#__codelineno-17-35"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-36" name="__codelineno-17-36" href="#__codelineno-17-36"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">stackPeek</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-17-37" name="__codelineno-17-37" href="#__codelineno-17-37"></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-17-38" name="__codelineno-17-38" href="#__codelineno-17-38"></a>
<a id="__codelineno-17-39" name="__codelineno-17-39" href="#__codelineno-17-39"></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">peek</span><span class="p">();</span>
<a id="__codelineno-17-40" name="__codelineno-17-40" href="#__codelineno-17-40"></a><span class="w"> </span><span class="n">stackPeek</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stackPeek</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-17-41" name="__codelineno-17-41" href="#__codelineno-17-41"></a><span class="w"> </span><span class="n">stkSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-17-42" name="__codelineno-17-42" href="#__codelineno-17-42"></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-17-43" name="__codelineno-17-43" href="#__codelineno-17-43"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-44" name="__codelineno-17-44" href="#__codelineno-17-44"></a>
<a id="__codelineno-17-45" name="__codelineno-17-45" href="#__codelineno-17-45"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-17-46" name="__codelineno-17-46" href="#__codelineno-17-46"></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">peek</span><span class="p">()</span>
<a id="__codelineno-17-47" name="__codelineno-17-47" href="#__codelineno-17-47"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-48" name="__codelineno-17-48" href="#__codelineno-17-48"></a><span class="w"> </span><span class="k">if</span><span class="w"> </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="m">0</span><span class="w"> </span><span class="o">||</span><span class="w"> </span><span class="n">stackPeek</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-17-49" name="__codelineno-17-49" href="#__codelineno-17-49"></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-17-50" name="__codelineno-17-50" href="#__codelineno-17-50"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stackPeek</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-17-51" name="__codelineno-17-51" href="#__codelineno-17-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-52" name="__codelineno-17-52" href="#__codelineno-17-52"></a>
<a id="__codelineno-17-53" name="__codelineno-17-53" href="#__codelineno-17-53"></a><span class="w"> </span><span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-17-54" name="__codelineno-17-54" href="#__codelineno-17-54"></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>
<a id="__codelineno-17-55" name="__codelineno-17-55" href="#__codelineno-17-55"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-56" name="__codelineno-17-56" href="#__codelineno-17-56"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">stackPeek</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-17-57" name="__codelineno-17-57" href="#__codelineno-17-57"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">Array</span><span class="p">.</span><span class="n">Empty</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="p">();</span>
<a id="__codelineno-17-58" name="__codelineno-17-58" href="#__codelineno-17-58"></a>
<a id="__codelineno-17-59" name="__codelineno-17-59" href="#__codelineno-17-59"></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">stackPeek</span><span class="p">;</span>
<a id="__codelineno-17-60" name="__codelineno-17-60" href="#__codelineno-17-60"></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-17-61" name="__codelineno-17-61" href="#__codelineno-17-61"></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="n">res</span><span class="p">.</span><span class="n">Length</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&gt;=</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="o">--</span><span class="p">)</span>
<a id="__codelineno-17-62" name="__codelineno-17-62" href="#__codelineno-17-62"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-63" name="__codelineno-17-63" href="#__codelineno-17-63"></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="n">val</span><span class="p">;</span>
<a id="__codelineno-17-64" name="__codelineno-17-64" href="#__codelineno-17-64"></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-17-65" name="__codelineno-17-65" href="#__codelineno-17-65"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-66" name="__codelineno-17-66" href="#__codelineno-17-66"></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-17-67" name="__codelineno-17-67" href="#__codelineno-17-67"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-68" name="__codelineno-17-68" href="#__codelineno-17-68"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.swift</span><pre><span></span><code><a id="__codelineno-18-1" name="__codelineno-18-1" href="#__codelineno-18-1"></a><span class="cm">/* 基于链表实现的栈 */</span>
<a id="__codelineno-18-2" name="__codelineno-18-2" href="#__codelineno-18-2"></a><span class="kd">class</span> <span class="nc">LinkedListStack</span> <span class="p">{</span>
<a id="__codelineno-18-3" name="__codelineno-18-3" href="#__codelineno-18-3"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">_peek</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 将头结点作为栈顶</span>
<a id="__codelineno-18-4" name="__codelineno-18-4" href="#__codelineno-18-4"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">_size</span> <span class="p">=</span> <span class="mi">0</span> <span class="c1">// 栈的长度</span>
<a id="__codelineno-18-5" name="__codelineno-18-5" href="#__codelineno-18-5"></a>
<a id="__codelineno-18-6" name="__codelineno-18-6" href="#__codelineno-18-6"></a> <span class="kd">init</span><span class="p">()</span> <span class="p">{}</span>
<a id="__codelineno-18-7" name="__codelineno-18-7" href="#__codelineno-18-7"></a>
<a id="__codelineno-18-8" name="__codelineno-18-8" href="#__codelineno-18-8"></a> <span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-18-9" name="__codelineno-18-9" href="#__codelineno-18-9"></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-18-10" name="__codelineno-18-10" href="#__codelineno-18-10"></a> <span class="n">_size</span>
<a id="__codelineno-18-11" name="__codelineno-18-11" href="#__codelineno-18-11"></a> <span class="p">}</span>
<a id="__codelineno-18-12" name="__codelineno-18-12" href="#__codelineno-18-12"></a>
<a id="__codelineno-18-13" name="__codelineno-18-13" href="#__codelineno-18-13"></a> <span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-18-14" name="__codelineno-18-14" href="#__codelineno-18-14"></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-18-15" name="__codelineno-18-15" href="#__codelineno-18-15"></a> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="mi">0</span>
<a id="__codelineno-18-16" name="__codelineno-18-16" href="#__codelineno-18-16"></a> <span class="p">}</span>
<a id="__codelineno-18-17" name="__codelineno-18-17" href="#__codelineno-18-17"></a>
<a id="__codelineno-18-18" name="__codelineno-18-18" href="#__codelineno-18-18"></a> <span class="cm">/* 入栈 */</span>
<a id="__codelineno-18-19" name="__codelineno-18-19" href="#__codelineno-18-19"></a> <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="p">{</span>
<a id="__codelineno-18-20" name="__codelineno-18-20" href="#__codelineno-18-20"></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">x</span><span class="p">:</span> <span class="n">num</span><span class="p">)</span>
<a id="__codelineno-18-21" name="__codelineno-18-21" href="#__codelineno-18-21"></a> <span class="n">node</span><span class="p">.</span><span class="n">next</span> <span class="p">=</span> <span class="n">_peek</span>
<a id="__codelineno-18-22" name="__codelineno-18-22" href="#__codelineno-18-22"></a> <span class="n">_peek</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-18-23" name="__codelineno-18-23" href="#__codelineno-18-23"></a> <span class="n">_size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-18-24" name="__codelineno-18-24" href="#__codelineno-18-24"></a> <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="cm">/* 出栈 */</span>
<a id="__codelineno-18-27" name="__codelineno-18-27" href="#__codelineno-18-27"></a> <span class="p">@</span><span class="n">discardableResult</span>
<a id="__codelineno-18-28" name="__codelineno-18-28" href="#__codelineno-18-28"></a> <span class="kd">func</span> <span class="nf">pop</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-29" name="__codelineno-18-29" href="#__codelineno-18-29"></a> <span class="kd">let</span> <span class="nv">num</span> <span class="p">=</span> <span class="n">peek</span><span class="p">()</span>
<a id="__codelineno-18-30" name="__codelineno-18-30" href="#__codelineno-18-30"></a> <span class="n">_peek</span> <span class="p">=</span> <span class="n">_peek</span><span class="p">?.</span><span class="n">next</span>
<a id="__codelineno-18-31" name="__codelineno-18-31" href="#__codelineno-18-31"></a> <span class="n">_size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-18-32" name="__codelineno-18-32" href="#__codelineno-18-32"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-18-33" name="__codelineno-18-33" href="#__codelineno-18-33"></a> <span class="p">}</span>
<a id="__codelineno-18-34" name="__codelineno-18-34" href="#__codelineno-18-34"></a>
<a id="__codelineno-18-35" name="__codelineno-18-35" href="#__codelineno-18-35"></a> <span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-18-36" name="__codelineno-18-36" href="#__codelineno-18-36"></a> <span class="kd">func</span> <span class="nf">peek</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-37" name="__codelineno-18-37" href="#__codelineno-18-37"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-18-38" name="__codelineno-18-38" href="#__codelineno-18-38"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;栈为空&quot;</span><span class="p">)</span>
<a id="__codelineno-18-39" name="__codelineno-18-39" href="#__codelineno-18-39"></a> <span class="p">}</span>
<a id="__codelineno-18-40" name="__codelineno-18-40" href="#__codelineno-18-40"></a> <span class="k">return</span> <span class="n">_peek</span><span class="p">!.</span><span class="n">val</span>
<a id="__codelineno-18-41" name="__codelineno-18-41" href="#__codelineno-18-41"></a> <span class="p">}</span>
<a id="__codelineno-18-42" name="__codelineno-18-42" href="#__codelineno-18-42"></a>
<a id="__codelineno-18-43" name="__codelineno-18-43" href="#__codelineno-18-43"></a> <span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-18-44" name="__codelineno-18-44" href="#__codelineno-18-44"></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-18-45" name="__codelineno-18-45" href="#__codelineno-18-45"></a> <span class="kd">var</span> <span class="nv">node</span> <span class="p">=</span> <span class="n">_peek</span>
<a id="__codelineno-18-46" name="__codelineno-18-46" href="#__codelineno-18-46"></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-18-47" name="__codelineno-18-47" href="#__codelineno-18-47"></a> <span class="k">for</span> <span class="n">i</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="n">res</span><span class="p">.</span><span class="bp">count</span> <span class="o">-</span> <span class="mi">1</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">&gt;=</span> <span class="mi">0</span> <span class="o">+</span> <span class="mi">1</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="kc">nil</span> <span class="p">})</span> <span class="p">{</span>
<a id="__codelineno-18-48" name="__codelineno-18-48" href="#__codelineno-18-48"></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-18-49" name="__codelineno-18-49" href="#__codelineno-18-49"></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-18-50" name="__codelineno-18-50" href="#__codelineno-18-50"></a> <span class="p">}</span>
<a id="__codelineno-18-51" name="__codelineno-18-51" href="#__codelineno-18-51"></a> <span class="k">return</span> <span class="n">res</span>
<a id="__codelineno-18-52" name="__codelineno-18-52" href="#__codelineno-18-52"></a> <span class="p">}</span>
<a id="__codelineno-18-53" name="__codelineno-18-53" href="#__codelineno-18-53"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_stack.zig</span><pre><span></span><code><a id="__codelineno-19-1" name="__codelineno-19-1" href="#__codelineno-19-1"></a><span class="c1">// 基于链表实现的栈</span>
<a id="__codelineno-19-2" name="__codelineno-19-2" href="#__codelineno-19-2"></a><span class="k">fn</span><span class="w"> </span><span class="n">LinkedListStack</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-19-3" name="__codelineno-19-3" href="#__codelineno-19-3"></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-19-4" name="__codelineno-19-4" href="#__codelineno-19-4"></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-19-5" name="__codelineno-19-5" href="#__codelineno-19-5"></a>
<a id="__codelineno-19-6" name="__codelineno-19-6" href="#__codelineno-19-6"></a><span class="w"> </span><span class="n">stack_top</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">inc</span><span class="p">.</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">// 将头结点作为栈顶</span>
<a id="__codelineno-19-7" name="__codelineno-19-7" href="#__codelineno-19-7"></a><span class="w"> </span><span class="n">stk_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">// 栈的长度</span>
<a id="__codelineno-19-8" name="__codelineno-19-8" href="#__codelineno-19-8"></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-19-9" name="__codelineno-19-9" href="#__codelineno-19-9"></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-19-10" name="__codelineno-19-10" href="#__codelineno-19-10"></a>
<a id="__codelineno-19-11" name="__codelineno-19-11" href="#__codelineno-19-11"></a><span class="w"> </span><span class="c1">// 构造方法(分配内存+初始化栈)</span>
<a id="__codelineno-19-12" name="__codelineno-19-12" href="#__codelineno-19-12"></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-19-13" name="__codelineno-19-13" href="#__codelineno-19-13"></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-19-14" name="__codelineno-19-14" href="#__codelineno-19-14"></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-19-15" name="__codelineno-19-15" href="#__codelineno-19-15"></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-19-16" name="__codelineno-19-16" href="#__codelineno-19-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-17" name="__codelineno-19-17" href="#__codelineno-19-17"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stack_top</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-19-18" name="__codelineno-19-18" href="#__codelineno-19-18"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stk_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-19-19" name="__codelineno-19-19" href="#__codelineno-19-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-20" name="__codelineno-19-20" href="#__codelineno-19-20"></a>
<a id="__codelineno-19-21" name="__codelineno-19-21" href="#__codelineno-19-21"></a><span class="w"> </span><span class="c1">// 析构方法(释放内存)</span>
<a id="__codelineno-19-22" name="__codelineno-19-22" href="#__codelineno-19-22"></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-19-23" name="__codelineno-19-23" href="#__codelineno-19-23"></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-19-24" name="__codelineno-19-24" href="#__codelineno-19-24"></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-19-25" name="__codelineno-19-25" href="#__codelineno-19-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-26" name="__codelineno-19-26" href="#__codelineno-19-26"></a>
<a id="__codelineno-19-27" name="__codelineno-19-27" href="#__codelineno-19-27"></a><span class="w"> </span><span class="c1">// 获取栈的长度</span>
<a id="__codelineno-19-28" name="__codelineno-19-28" href="#__codelineno-19-28"></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-19-29" name="__codelineno-19-29" href="#__codelineno-19-29"></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">stk_size</span><span class="p">;</span>
<a id="__codelineno-19-30" name="__codelineno-19-30" href="#__codelineno-19-30"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-31" name="__codelineno-19-31" href="#__codelineno-19-31"></a>
<a id="__codelineno-19-32" name="__codelineno-19-32" href="#__codelineno-19-32"></a><span class="w"> </span><span class="c1">// 判断栈是否为空</span>
<a id="__codelineno-19-33" name="__codelineno-19-33" href="#__codelineno-19-33"></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-19-34" name="__codelineno-19-34" href="#__codelineno-19-34"></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-19-35" name="__codelineno-19-35" href="#__codelineno-19-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-36" name="__codelineno-19-36" href="#__codelineno-19-36"></a>
<a id="__codelineno-19-37" name="__codelineno-19-37" href="#__codelineno-19-37"></a><span class="w"> </span><span class="c1">// 访问栈顶元素</span>
<a id="__codelineno-19-38" name="__codelineno-19-38" href="#__codelineno-19-38"></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">peek</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-19-39" name="__codelineno-19-39" href="#__codelineno-19-39"></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">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><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;栈为空&quot;</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="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stack_top</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-19-41" name="__codelineno-19-41" href="#__codelineno-19-41"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-42" name="__codelineno-19-42" href="#__codelineno-19-42"></a>
<a id="__codelineno-19-43" name="__codelineno-19-43" href="#__codelineno-19-43"></a><span class="w"> </span><span class="c1">// 入栈</span>
<a id="__codelineno-19-44" name="__codelineno-19-44" href="#__codelineno-19-44"></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="o">!</span><span class="kt">void</span><span class="w"> </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="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">inc</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-19-46" name="__codelineno-19-46" href="#__codelineno-19-46"></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-19-47" name="__codelineno-19-47" href="#__codelineno-19-47"></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">stack_top</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="n">self</span><span class="p">.</span><span class="n">stack_top</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-19-49" name="__codelineno-19-49" href="#__codelineno-19-49"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stk_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-19-50" name="__codelineno-19-50" href="#__codelineno-19-50"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-51" name="__codelineno-19-51" href="#__codelineno-19-51"></a>
<a id="__codelineno-19-52" name="__codelineno-19-52" href="#__codelineno-19-52"></a><span class="w"> </span><span class="c1">// 出栈</span>
<a id="__codelineno-19-53" name="__codelineno-19-53" href="#__codelineno-19-53"></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">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">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-54" name="__codelineno-19-54" href="#__codelineno-19-54"></a><span class="w"> </span><span class="kr">var</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">self</span><span class="p">.</span><span class="n">peek</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="n">self</span><span class="p">.</span><span class="n">stack_top</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">stack_top</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-19-56" name="__codelineno-19-56" href="#__codelineno-19-56"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stk_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-19-57" name="__codelineno-19-57" href="#__codelineno-19-57"></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-19-58" name="__codelineno-19-58" href="#__codelineno-19-58"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-59" name="__codelineno-19-59" href="#__codelineno-19-59"></a>
<a id="__codelineno-19-60" name="__codelineno-19-60" href="#__codelineno-19-60"></a><span class="w"> </span><span class="c1">// 将栈转换为数组</span>
<a id="__codelineno-19-61" name="__codelineno-19-61" href="#__codelineno-19-61"></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-19-62" name="__codelineno-19-62" href="#__codelineno-19-62"></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">stack_top</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="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-19-64" name="__codelineno-19-64" href="#__codelineno-19-64"></a><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">set</span><span class="p">(</span><span class="n">T</span><span class="p">,</span><span class="w"> </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-19-65" name="__codelineno-19-65" href="#__codelineno-19-65"></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-19-66" name="__codelineno-19-66" href="#__codelineno-19-66"></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-19-67" name="__codelineno-19-67" href="#__codelineno-19-67"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">res</span><span class="p">.</span><span class="n">len</span><span class="w"> </span><span class="o">-</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">1</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-19-68" name="__codelineno-19-68" href="#__codelineno-19-68"></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-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">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-19-71" name="__codelineno-19-71" href="#__codelineno-19-71"></a><span class="w"> </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="p">};</span>
<a id="__codelineno-19-73" name="__codelineno-19-73" href="#__codelineno-19-73"></a><span class="p">}</span>
</code></pre></div>
</div>
</div>
</div>
<h3 id="_2">基于数组的实现<a class="headerlink" href="#_2" title="Permanent link">&para;</a></h3>
<p>使用「数组」实现栈时,考虑将数组的尾部当作栈顶。这样设计下,「入栈」与「出栈」操作就对应在数组尾部「添加元素」与「删除元素」,时间复杂度都为 <span class="arithmatex">\(O(1)\)</span></p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:3"><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" /><div class="tabbed-labels"><label for="__tabbed_4_1">ArrayStack</label><label for="__tabbed_4_2">push()</label><label for="__tabbed_4_3">pop()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><img alt="基于数组实现栈的入栈出栈操作" src="../stack.assets/array_stack.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_stack_push" src="../stack.assets/array_stack_push.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_stack_pop" src="../stack.assets/array_stack_pop.png" /></p>
</div>
</div>
</div>
<p>由于入栈的元素可能是源源不断的,因此可以使用支持动态扩容的「列表」,这样就无需自行实现数组扩容了。以下是示例代码。</p>
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<div class="highlight"><span class="filename">array_stack.java</span><pre><span></span><code><a id="__codelineno-20-1" name="__codelineno-20-1" href="#__codelineno-20-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-20-2" name="__codelineno-20-2" href="#__codelineno-20-2"></a><span class="kd">class</span> <span class="nc">ArrayStack</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="kd">private</span><span class="w"> </span><span class="n">ArrayList</span><span class="o">&lt;</span><span class="n">Integer</span><span class="o">&gt;</span><span class="w"> </span><span class="n">stack</span><span class="p">;</span>
<a id="__codelineno-20-4" name="__codelineno-20-4" href="#__codelineno-20-4"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">ArrayStack</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-5" name="__codelineno-20-5" href="#__codelineno-20-5"></a><span class="w"> </span><span class="c1">// 初始化列表(动态数组)</span>
<a id="__codelineno-20-6" name="__codelineno-20-6" href="#__codelineno-20-6"></a><span class="w"> </span><span class="n">stack</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">ArrayList</span><span class="o">&lt;&gt;</span><span class="p">();</span>
<a id="__codelineno-20-7" name="__codelineno-20-7" href="#__codelineno-20-7"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-8" name="__codelineno-20-8" href="#__codelineno-20-8"></a>
<a id="__codelineno-20-9" name="__codelineno-20-9" href="#__codelineno-20-9"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-20-10" name="__codelineno-20-10" href="#__codelineno-20-10"></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-20-11" name="__codelineno-20-11" href="#__codelineno-20-11"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">size</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="p">}</span>
<a id="__codelineno-20-13" name="__codelineno-20-13" href="#__codelineno-20-13"></a>
<a id="__codelineno-20-14" name="__codelineno-20-14" href="#__codelineno-20-14"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-20-15" name="__codelineno-20-15" href="#__codelineno-20-15"></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-20-16" name="__codelineno-20-16" href="#__codelineno-20-16"></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-20-17" name="__codelineno-20-17" href="#__codelineno-20-17"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-18" name="__codelineno-20-18" href="#__codelineno-20-18"></a>
<a id="__codelineno-20-19" name="__codelineno-20-19" href="#__codelineno-20-19"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-20-20" name="__codelineno-20-20" href="#__codelineno-20-20"></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">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="p">{</span>
<a id="__codelineno-20-21" name="__codelineno-20-21" href="#__codelineno-20-21"></a><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">add</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-20-22" name="__codelineno-20-22" href="#__codelineno-20-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-23" name="__codelineno-20-23" href="#__codelineno-20-23"></a>
<a id="__codelineno-20-24" name="__codelineno-20-24" href="#__codelineno-20-24"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-20-25" name="__codelineno-20-25" href="#__codelineno-20-25"></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">pop</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-26" name="__codelineno-20-26" href="#__codelineno-20-26"></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-20-27" name="__codelineno-20-27" href="#__codelineno-20-27"></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">EmptyStackException</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">stack</span><span class="p">.</span><span class="na">remove</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">1</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">/* 访问栈顶元素 */</span>
<a id="__codelineno-20-32" name="__codelineno-20-32" href="#__codelineno-20-32"></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">peek</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="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</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">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">EmptyStackException</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="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">get</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">1</span><span class="p">);</span>
<a id="__codelineno-20-36" name="__codelineno-20-36" href="#__codelineno-20-36"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-37" name="__codelineno-20-37" href="#__codelineno-20-37"></a>
<a id="__codelineno-20-38" name="__codelineno-20-38" href="#__codelineno-20-38"></a><span class="w"> </span><span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-20-39" name="__codelineno-20-39" href="#__codelineno-20-39"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">Object</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-20-40" name="__codelineno-20-40" href="#__codelineno-20-40"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="na">toArray</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="p">}</span>
<a id="__codelineno-20-42" name="__codelineno-20-42" href="#__codelineno-20-42"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.cpp</span><pre><span></span><code><a id="__codelineno-21-1" name="__codelineno-21-1" href="#__codelineno-21-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-21-2" name="__codelineno-21-2" href="#__codelineno-21-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ArrayStack</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="k">private</span><span class="o">:</span>
<a id="__codelineno-21-4" name="__codelineno-21-4" href="#__codelineno-21-4"></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">stack</span><span class="p">;</span>
<a id="__codelineno-21-5" name="__codelineno-21-5" href="#__codelineno-21-5"></a>
<a id="__codelineno-21-6" name="__codelineno-21-6" href="#__codelineno-21-6"></a><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-21-7" name="__codelineno-21-7" href="#__codelineno-21-7"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-21-8" name="__codelineno-21-8" href="#__codelineno-21-8"></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-21-9" name="__codelineno-21-9" href="#__codelineno-21-9"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">size</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="p">}</span>
<a id="__codelineno-21-11" name="__codelineno-21-11" href="#__codelineno-21-11"></a>
<a id="__codelineno-21-12" name="__codelineno-21-12" href="#__codelineno-21-12"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-21-13" name="__codelineno-21-13" href="#__codelineno-21-13"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">empty</span><span class="p">()</span><span class="w"> </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="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">empty</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>
<a id="__codelineno-21-17" name="__codelineno-21-17" href="#__codelineno-21-17"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-21-18" name="__codelineno-21-18" href="#__codelineno-21-18"></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="p">{</span>
<a id="__codelineno-21-19" name="__codelineno-21-19" href="#__codelineno-21-19"></a><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-21-20" name="__codelineno-21-20" href="#__codelineno-21-20"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-21" name="__codelineno-21-21" href="#__codelineno-21-21"></a>
<a id="__codelineno-21-22" name="__codelineno-21-22" href="#__codelineno-21-22"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-21-23" name="__codelineno-21-23" href="#__codelineno-21-23"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pop</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-24" name="__codelineno-21-24" href="#__codelineno-21-24"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">oldTop</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">top</span><span class="p">();</span>
<a id="__codelineno-21-25" name="__codelineno-21-25" href="#__codelineno-21-25"></a><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">pop_back</span><span class="p">();</span>
<a id="__codelineno-21-26" name="__codelineno-21-26" href="#__codelineno-21-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-27" name="__codelineno-21-27" href="#__codelineno-21-27"></a>
<a id="__codelineno-21-28" name="__codelineno-21-28" href="#__codelineno-21-28"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-21-29" name="__codelineno-21-29" href="#__codelineno-21-29"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">top</span><span class="p">()</span><span class="w"> </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="k">if</span><span class="p">(</span><span class="n">empty</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="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;栈为空&quot;</span><span class="p">);</span>
<a id="__codelineno-21-32" name="__codelineno-21-32" href="#__codelineno-21-32"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">back</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">/* 返回 Vector */</span>
<a id="__codelineno-21-36" name="__codelineno-21-36" href="#__codelineno-21-36"></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-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="n">stack</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><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.py</span><pre><span></span><code><a id="__codelineno-22-1" name="__codelineno-22-1" href="#__codelineno-22-1"></a><span class="k">class</span> <span class="nc">ArrayStack</span><span class="p">:</span>
<a id="__codelineno-22-2" name="__codelineno-22-2" href="#__codelineno-22-2"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 基于数组实现的栈 &quot;&quot;&quot;</span>
<a id="__codelineno-22-3" name="__codelineno-22-3" href="#__codelineno-22-3"></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="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-22-4" name="__codelineno-22-4" href="#__codelineno-22-4"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 构造方法 &quot;&quot;&quot;</span>
<a id="__codelineno-22-5" name="__codelineno-22-5" href="#__codelineno-22-5"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</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>
<a id="__codelineno-22-6" name="__codelineno-22-6" href="#__codelineno-22-6"></a>
<a id="__codelineno-22-7" name="__codelineno-22-7" href="#__codelineno-22-7"></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-22-8" name="__codelineno-22-8" href="#__codelineno-22-8"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 获取栈的长度 &quot;&quot;&quot;</span>
<a id="__codelineno-22-9" name="__codelineno-22-9" href="#__codelineno-22-9"></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">__stack</span><span class="p">)</span>
<a id="__codelineno-22-10" name="__codelineno-22-10" href="#__codelineno-22-10"></a>
<a id="__codelineno-22-11" name="__codelineno-22-11" href="#__codelineno-22-11"></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-22-12" name="__codelineno-22-12" href="#__codelineno-22-12"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 判断栈是否为空 &quot;&quot;&quot;</span>
<a id="__codelineno-22-13" name="__codelineno-22-13" href="#__codelineno-22-13"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</span> <span class="o">==</span> <span class="p">[]</span>
<a id="__codelineno-22-14" name="__codelineno-22-14" href="#__codelineno-22-14"></a>
<a id="__codelineno-22-15" name="__codelineno-22-15" href="#__codelineno-22-15"></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">item</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</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="sd">&quot;&quot;&quot; 入栈 &quot;&quot;&quot;</span>
<a id="__codelineno-22-17" name="__codelineno-22-17" href="#__codelineno-22-17"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">item</span><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="k">def</span> <span class="nf">pop</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-22-20" name="__codelineno-22-20" href="#__codelineno-22-20"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 出栈 &quot;&quot;&quot;</span>
<a id="__codelineno-22-21" name="__codelineno-22-21" href="#__codelineno-22-21"></a> <span class="k">assert</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">(),</span> <span class="s2">&quot;栈为空&quot;</span>
<a id="__codelineno-22-22" name="__codelineno-22-22" href="#__codelineno-22-22"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</span><span class="o">.</span><span class="n">pop</span><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="k">def</span> <span class="nf">peek</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-22-25" name="__codelineno-22-25" href="#__codelineno-22-25"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 访问栈顶元素 &quot;&quot;&quot;</span>
<a id="__codelineno-22-26" name="__codelineno-22-26" href="#__codelineno-22-26"></a> <span class="k">assert</span> <span class="ow">not</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">(),</span> <span class="s2">&quot;栈为空&quot;</span>
<a id="__codelineno-22-27" name="__codelineno-22-27" href="#__codelineno-22-27"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span>
<a id="__codelineno-22-28" name="__codelineno-22-28" href="#__codelineno-22-28"></a>
<a id="__codelineno-22-29" name="__codelineno-22-29" href="#__codelineno-22-29"></a> <span class="k">def</span> <span class="nf">to_list</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-22-30" name="__codelineno-22-30" href="#__codelineno-22-30"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot; 返回列表用于打印 &quot;&quot;&quot;</span>
<a id="__codelineno-22-31" name="__codelineno-22-31" href="#__codelineno-22-31"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__stack</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.go</span><pre><span></span><code><a id="__codelineno-23-1" name="__codelineno-23-1" href="#__codelineno-23-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-23-2" name="__codelineno-23-2" href="#__codelineno-23-2"></a><span class="kd">type</span><span class="w"> </span><span class="nx">arrayStack</span><span class="w"> </span><span class="kd">struct</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="nx">data</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="w"> </span><span class="c1">// 数据</span>
<a id="__codelineno-23-4" name="__codelineno-23-4" href="#__codelineno-23-4"></a><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="cm">/* 初始化栈 */</span>
<a id="__codelineno-23-7" name="__codelineno-23-7" href="#__codelineno-23-7"></a><span class="kd">func</span><span class="w"> </span><span class="nx">newArrayStack</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayStack</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-8" name="__codelineno-23-8" href="#__codelineno-23-8"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">&amp;</span><span class="nx">arrayStack</span><span class="p">{</span>
<a id="__codelineno-23-9" name="__codelineno-23-9" href="#__codelineno-23-9"></a><span class="w"> </span><span class="c1">// 设置栈的长度为 0容量为 16</span>
<a id="__codelineno-23-10" name="__codelineno-23-10" href="#__codelineno-23-10"></a><span class="w"> </span><span class="nx">data</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="mi">0</span><span class="p">,</span><span class="w"> </span><span class="mi">16</span><span class="p">),</span>
<a id="__codelineno-23-11" name="__codelineno-23-11" href="#__codelineno-23-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-12" name="__codelineno-23-12" href="#__codelineno-23-12"></a><span class="p">}</span>
<a id="__codelineno-23-13" name="__codelineno-23-13" href="#__codelineno-23-13"></a>
<a id="__codelineno-23-14" name="__codelineno-23-14" href="#__codelineno-23-14"></a><span class="cm">/* 栈的长度 */</span>
<a id="__codelineno-23-15" name="__codelineno-23-15" href="#__codelineno-23-15"></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">arrayStack</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-23-16" name="__codelineno-23-16" href="#__codelineno-23-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nb">len</span><span class="p">(</span><span class="nx">s</span><span class="p">.</span><span class="nx">data</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="cm">/* 栈是否为空 */</span>
<a id="__codelineno-23-20" name="__codelineno-23-20" href="#__codelineno-23-20"></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">arrayStack</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-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="nx">s</span><span class="p">.</span><span class="nx">size</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-23-22" name="__codelineno-23-22" href="#__codelineno-23-22"></a><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="cm">/* 入栈 */</span>
<a id="__codelineno-23-25" name="__codelineno-23-25" href="#__codelineno-23-25"></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">arrayStack</span><span class="p">)</span><span class="w"> </span><span class="nx">push</span><span class="p">(</span><span class="nx">v</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-23-26" name="__codelineno-23-26" href="#__codelineno-23-26"></a><span class="w"> </span><span class="c1">// 切片会自动扩容</span>
<a id="__codelineno-23-27" name="__codelineno-23-27" href="#__codelineno-23-27"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nb">append</span><span class="p">(</span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">,</span><span class="w"> </span><span class="nx">v</span><span class="p">)</span>
<a id="__codelineno-23-28" name="__codelineno-23-28" href="#__codelineno-23-28"></a><span class="p">}</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="cm">/* 出栈 */</span>
<a id="__codelineno-23-31" name="__codelineno-23-31" href="#__codelineno-23-31"></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">arrayStack</span><span class="p">)</span><span class="w"> </span><span class="nx">pop</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-23-32" name="__codelineno-23-32" href="#__codelineno-23-32"></a><span class="w"> </span><span class="nx">val</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">peek</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="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="w"> </span><span class="p">=</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="nb">len</span><span class="p">(</span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">)</span><span class="o">-</span><span class="mi">1</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="k">return</span><span class="w"> </span><span class="nx">val</span>
<a id="__codelineno-23-35" name="__codelineno-23-35" href="#__codelineno-23-35"></a><span class="p">}</span>
<a id="__codelineno-23-36" name="__codelineno-23-36" href="#__codelineno-23-36"></a>
<a id="__codelineno-23-37" name="__codelineno-23-37" href="#__codelineno-23-37"></a><span class="cm">/* 获取栈顶元素 */</span>
<a id="__codelineno-23-38" name="__codelineno-23-38" href="#__codelineno-23-38"></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">arrayStack</span><span class="p">)</span><span class="w"> </span><span class="nx">peek</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-23-39" name="__codelineno-23-39" href="#__codelineno-23-39"></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-23-40" name="__codelineno-23-40" href="#__codelineno-23-40"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-23-41" name="__codelineno-23-41" href="#__codelineno-23-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-42" name="__codelineno-23-42" href="#__codelineno-23-42"></a><span class="w"> </span><span class="nx">val</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="nb">len</span><span class="p">(</span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">)</span><span class="o">-</span><span class="mi">1</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">return</span><span class="w"> </span><span class="nx">val</span>
<a id="__codelineno-23-44" name="__codelineno-23-44" href="#__codelineno-23-44"></a><span class="p">}</span>
<a id="__codelineno-23-45" name="__codelineno-23-45" href="#__codelineno-23-45"></a>
<a id="__codelineno-23-46" name="__codelineno-23-46" href="#__codelineno-23-46"></a><span class="cm">/* 获取 Slice 用于打印 */</span>
<a id="__codelineno-23-47" name="__codelineno-23-47" href="#__codelineno-23-47"></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">arrayStack</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-23-48" name="__codelineno-23-48" href="#__codelineno-23-48"></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-23-49" name="__codelineno-23-49" href="#__codelineno-23-49"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.js</span><pre><span></span><code><a id="__codelineno-24-1" name="__codelineno-24-1" href="#__codelineno-24-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-24-2" name="__codelineno-24-2" href="#__codelineno-24-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ArrayStack</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-3" name="__codelineno-24-3" href="#__codelineno-24-3"></a><span class="w"> </span><span class="err">#</span><span class="nx">stack</span><span class="p">;</span>
<a id="__codelineno-24-4" name="__codelineno-24-4" href="#__codelineno-24-4"></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-24-5" name="__codelineno-24-5" href="#__codelineno-24-5"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stack</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-24-6" name="__codelineno-24-6" href="#__codelineno-24-6"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-7" name="__codelineno-24-7" href="#__codelineno-24-7"></a>
<a id="__codelineno-24-8" name="__codelineno-24-8" href="#__codelineno-24-8"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-24-9" name="__codelineno-24-9" href="#__codelineno-24-9"></a><span class="w"> </span><span class="nx">get</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-10" name="__codelineno-24-10" href="#__codelineno-24-10"></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">stack</span><span class="p">.</span><span class="nx">length</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="p">}</span>
<a id="__codelineno-24-12" name="__codelineno-24-12" href="#__codelineno-24-12"></a>
<a id="__codelineno-24-13" name="__codelineno-24-13" href="#__codelineno-24-13"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-24-14" name="__codelineno-24-14" href="#__codelineno-24-14"></a><span class="w"> </span><span class="nx">empty</span><span class="p">()</span><span class="w"> </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="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stack</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">0</span><span class="p">;</span>
<a id="__codelineno-24-16" name="__codelineno-24-16" href="#__codelineno-24-16"></a><span class="w"> </span><span class="p">}</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="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-24-19" name="__codelineno-24-19" href="#__codelineno-24-19"></a><span class="w"> </span><span class="nx">push</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-24-20" name="__codelineno-24-20" href="#__codelineno-24-20"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">num</span><span class="p">);</span>
<a id="__codelineno-24-21" name="__codelineno-24-21" href="#__codelineno-24-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-22" name="__codelineno-24-22" href="#__codelineno-24-22"></a>
<a id="__codelineno-24-23" name="__codelineno-24-23" href="#__codelineno-24-23"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-24-24" name="__codelineno-24-24" href="#__codelineno-24-24"></a><span class="w"> </span><span class="nx">pop</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-25" name="__codelineno-24-25" href="#__codelineno-24-25"></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">empty</span><span class="p">())</span>
<a id="__codelineno-24-26" name="__codelineno-24-26" href="#__codelineno-24-26"></a><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="s2">&quot;栈为空&quot;</span><span class="p">);</span>
<a id="__codelineno-24-27" name="__codelineno-24-27" href="#__codelineno-24-27"></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">stack</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<a id="__codelineno-24-28" name="__codelineno-24-28" href="#__codelineno-24-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-29" name="__codelineno-24-29" href="#__codelineno-24-29"></a>
<a id="__codelineno-24-30" name="__codelineno-24-30" href="#__codelineno-24-30"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-24-31" name="__codelineno-24-31" href="#__codelineno-24-31"></a><span class="w"> </span><span class="nx">top</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-32" name="__codelineno-24-32" href="#__codelineno-24-32"></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">empty</span><span class="p">())</span>
<a id="__codelineno-24-33" name="__codelineno-24-33" href="#__codelineno-24-33"></a><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="s2">&quot;栈为空&quot;</span><span class="p">);</span>
<a id="__codelineno-24-34" name="__codelineno-24-34" href="#__codelineno-24-34"></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">stack</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">stack</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-24-35" name="__codelineno-24-35" href="#__codelineno-24-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-36" name="__codelineno-24-36" href="#__codelineno-24-36"></a>
<a id="__codelineno-24-37" name="__codelineno-24-37" href="#__codelineno-24-37"></a><span class="w"> </span><span class="cm">/* 返回 Array */</span>
<a id="__codelineno-24-38" name="__codelineno-24-38" href="#__codelineno-24-38"></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-24-39" name="__codelineno-24-39" href="#__codelineno-24-39"></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">stack</span><span class="p">;</span>
<a id="__codelineno-24-40" name="__codelineno-24-40" href="#__codelineno-24-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-41" name="__codelineno-24-41" href="#__codelineno-24-41"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.ts</span><pre><span></span><code><a id="__codelineno-25-1" name="__codelineno-25-1" href="#__codelineno-25-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-25-2" name="__codelineno-25-2" href="#__codelineno-25-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ArrayStack</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="w"> </span><span class="nx">stack</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[];</span>
<a id="__codelineno-25-4" name="__codelineno-25-4" href="#__codelineno-25-4"></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-25-5" name="__codelineno-25-5" href="#__codelineno-25-5"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stack</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-25-6" name="__codelineno-25-6" href="#__codelineno-25-6"></a><span class="w"> </span><span class="p">}</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="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-25-9" name="__codelineno-25-9" href="#__codelineno-25-9"></a><span class="w"> </span><span class="nx">get</span><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-25-10" name="__codelineno-25-10" href="#__codelineno-25-10"></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">stack</span><span class="p">.</span><span class="nx">length</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="p">}</span>
<a id="__codelineno-25-12" name="__codelineno-25-12" href="#__codelineno-25-12"></a>
<a id="__codelineno-25-13" name="__codelineno-25-13" href="#__codelineno-25-13"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-25-14" name="__codelineno-25-14" href="#__codelineno-25-14"></a><span class="w"> </span><span class="nx">empty</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-25-15" name="__codelineno-25-15" href="#__codelineno-25-15"></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">stack</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">0</span><span class="p">;</span>
<a id="__codelineno-25-16" name="__codelineno-25-16" href="#__codelineno-25-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-17" name="__codelineno-25-17" href="#__codelineno-25-17"></a>
<a id="__codelineno-25-18" name="__codelineno-25-18" href="#__codelineno-25-18"></a><span class="w"> </span><span class="cm">/* 入栈 */</span>
<a id="__codelineno-25-19" name="__codelineno-25-19" href="#__codelineno-25-19"></a><span class="w"> </span><span class="nx">push</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-25-20" name="__codelineno-25-20" href="#__codelineno-25-20"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">stack</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">num</span><span class="p">);</span>
<a id="__codelineno-25-21" name="__codelineno-25-21" href="#__codelineno-25-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-22" name="__codelineno-25-22" href="#__codelineno-25-22"></a>
<a id="__codelineno-25-23" name="__codelineno-25-23" href="#__codelineno-25-23"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-25-24" name="__codelineno-25-24" href="#__codelineno-25-24"></a><span class="w"> </span><span class="nx">pop</span><span class="p">()</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="kc">undefined</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-25" name="__codelineno-25-25" href="#__codelineno-25-25"></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">empty</span><span class="p">())</span>
<a id="__codelineno-25-26" name="__codelineno-25-26" href="#__codelineno-25-26"></a><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;栈为空&#39;</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="k">this</span><span class="p">.</span><span class="nx">stack</span><span class="p">.</span><span class="nx">pop</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">/* 访问栈顶元素 */</span>
<a id="__codelineno-25-31" name="__codelineno-25-31" href="#__codelineno-25-31"></a><span class="w"> </span><span class="nx">top</span><span class="p">()</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="kc">undefined</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="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">empty</span><span class="p">())</span>
<a id="__codelineno-25-33" name="__codelineno-25-33" href="#__codelineno-25-33"></a><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;栈为空&#39;</span><span class="p">);</span>
<a id="__codelineno-25-34" name="__codelineno-25-34" href="#__codelineno-25-34"></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">stack</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">stack</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-25-35" name="__codelineno-25-35" href="#__codelineno-25-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-36" name="__codelineno-25-36" href="#__codelineno-25-36"></a>
<a id="__codelineno-25-37" name="__codelineno-25-37" href="#__codelineno-25-37"></a><span class="w"> </span><span class="cm">/* 返回 Array */</span>
<a id="__codelineno-25-38" name="__codelineno-25-38" href="#__codelineno-25-38"></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-25-39" name="__codelineno-25-39" href="#__codelineno-25-39"></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">stack</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="p">}</span>
<a id="__codelineno-25-41" name="__codelineno-25-41" href="#__codelineno-25-41"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.c</span><pre><span></span><code><a id="__codelineno-26-1" name="__codelineno-26-1" href="#__codelineno-26-1"></a><span class="p">[</span><span class="n">class</span><span class="p">]{</span><span class="n">arrayStack</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 class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.cs</span><pre><span></span><code><a id="__codelineno-27-1" name="__codelineno-27-1" href="#__codelineno-27-1"></a><span class="cm">/* 基于数组实现的栈 */</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">ArrayStack</span>
<a id="__codelineno-27-3" name="__codelineno-27-3" href="#__codelineno-27-3"></a><span class="p">{</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="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">stack</span><span class="p">;</span>
<a id="__codelineno-27-5" name="__codelineno-27-5" href="#__codelineno-27-5"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">ArrayStack</span><span class="p">()</span>
<a id="__codelineno-27-6" name="__codelineno-27-6" href="#__codelineno-27-6"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-7" name="__codelineno-27-7" href="#__codelineno-27-7"></a><span class="w"> </span><span class="c1">// 初始化列表(动态数组)</span>
<a id="__codelineno-27-8" name="__codelineno-27-8" href="#__codelineno-27-8"></a><span class="w"> </span><span class="n">stack</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-27-9" name="__codelineno-27-9" href="#__codelineno-27-9"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-10" name="__codelineno-27-10" href="#__codelineno-27-10"></a>
<a id="__codelineno-27-11" name="__codelineno-27-11" href="#__codelineno-27-11"></a><span class="w"> </span><span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-27-12" name="__codelineno-27-12" href="#__codelineno-27-12"></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>
<a id="__codelineno-27-13" name="__codelineno-27-13" href="#__codelineno-27-13"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-14" name="__codelineno-27-14" href="#__codelineno-27-14"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">Count</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="p">}</span>
<a id="__codelineno-27-16" name="__codelineno-27-16" href="#__codelineno-27-16"></a>
<a id="__codelineno-27-17" name="__codelineno-27-17" href="#__codelineno-27-17"></a><span class="w"> </span><span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-27-18" name="__codelineno-27-18" href="#__codelineno-27-18"></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>
<a id="__codelineno-27-19" name="__codelineno-27-19" href="#__codelineno-27-19"></a><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="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-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">/* 入栈 */</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="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>
<a id="__codelineno-27-25" name="__codelineno-27-25" href="#__codelineno-27-25"></a><span class="w"> </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="n">stack</span><span class="p">.</span><span class="n">Add</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-27-27" name="__codelineno-27-27" href="#__codelineno-27-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-28" name="__codelineno-27-28" href="#__codelineno-27-28"></a>
<a id="__codelineno-27-29" name="__codelineno-27-29" href="#__codelineno-27-29"></a><span class="w"> </span><span class="cm">/* 出栈 */</span>
<a id="__codelineno-27-30" name="__codelineno-27-30" href="#__codelineno-27-30"></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">pop</span><span class="p">()</span>
<a id="__codelineno-27-31" name="__codelineno-27-31" href="#__codelineno-27-31"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-32" name="__codelineno-27-32" href="#__codelineno-27-32"></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-27-33" name="__codelineno-27-33" href="#__codelineno-27-33"></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-27-34" name="__codelineno-27-34" href="#__codelineno-27-34"></a><span class="w"> </span><span class="kt">var</span><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peek</span><span class="p">();</span>
<a id="__codelineno-27-35" name="__codelineno-27-35" href="#__codelineno-27-35"></a><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">RemoveAt</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="m">1</span><span class="p">);</span>
<a id="__codelineno-27-36" name="__codelineno-27-36" href="#__codelineno-27-36"></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-27-37" name="__codelineno-27-37" href="#__codelineno-27-37"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-38" name="__codelineno-27-38" href="#__codelineno-27-38"></a>
<a id="__codelineno-27-39" name="__codelineno-27-39" href="#__codelineno-27-39"></a><span class="w"> </span><span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-27-40" name="__codelineno-27-40" href="#__codelineno-27-40"></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">peek</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="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-27-43" name="__codelineno-27-43" href="#__codelineno-27-43"></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-27-44" name="__codelineno-27-44" href="#__codelineno-27-44"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</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="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="p">}</span>
<a id="__codelineno-27-46" name="__codelineno-27-46" href="#__codelineno-27-46"></a>
<a id="__codelineno-27-47" name="__codelineno-27-47" href="#__codelineno-27-47"></a><span class="w"> </span><span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-27-48" name="__codelineno-27-48" href="#__codelineno-27-48"></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>
<a id="__codelineno-27-49" name="__codelineno-27-49" href="#__codelineno-27-49"></a><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-50" name="__codelineno-27-50" href="#__codelineno-27-50"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">stack</span><span class="p">.</span><span class="n">ToArray</span><span class="p">();</span>
<a id="__codelineno-27-51" name="__codelineno-27-51" href="#__codelineno-27-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-52" name="__codelineno-27-52" href="#__codelineno-27-52"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.swift</span><pre><span></span><code><a id="__codelineno-28-1" name="__codelineno-28-1" href="#__codelineno-28-1"></a><span class="cm">/* 基于数组实现的栈 */</span>
<a id="__codelineno-28-2" name="__codelineno-28-2" href="#__codelineno-28-2"></a><span class="kd">class</span> <span class="nc">ArrayStack</span> <span class="p">{</span>
<a id="__codelineno-28-3" name="__codelineno-28-3" href="#__codelineno-28-3"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">stack</span><span class="p">:</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span>
<a id="__codelineno-28-4" name="__codelineno-28-4" href="#__codelineno-28-4"></a>
<a id="__codelineno-28-5" name="__codelineno-28-5" href="#__codelineno-28-5"></a> <span class="kd">init</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-6" name="__codelineno-28-6" href="#__codelineno-28-6"></a> <span class="c1">// 初始化列表(动态数组)</span>
<a id="__codelineno-28-7" name="__codelineno-28-7" href="#__codelineno-28-7"></a> <span class="n">stack</span> <span class="p">=</span> <span class="p">[]</span>
<a id="__codelineno-28-8" name="__codelineno-28-8" href="#__codelineno-28-8"></a> <span class="p">}</span>
<a id="__codelineno-28-9" name="__codelineno-28-9" href="#__codelineno-28-9"></a>
<a id="__codelineno-28-10" name="__codelineno-28-10" href="#__codelineno-28-10"></a> <span class="cm">/* 获取栈的长度 */</span>
<a id="__codelineno-28-11" name="__codelineno-28-11" href="#__codelineno-28-11"></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-28-12" name="__codelineno-28-12" href="#__codelineno-28-12"></a> <span class="n">stack</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-28-13" name="__codelineno-28-13" href="#__codelineno-28-13"></a> <span class="p">}</span>
<a id="__codelineno-28-14" name="__codelineno-28-14" href="#__codelineno-28-14"></a>
<a id="__codelineno-28-15" name="__codelineno-28-15" href="#__codelineno-28-15"></a> <span class="cm">/* 判断栈是否为空 */</span>
<a id="__codelineno-28-16" name="__codelineno-28-16" href="#__codelineno-28-16"></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-28-17" name="__codelineno-28-17" href="#__codelineno-28-17"></a> <span class="n">stack</span><span class="p">.</span><span class="bp">isEmpty</span>
<a id="__codelineno-28-18" name="__codelineno-28-18" href="#__codelineno-28-18"></a> <span class="p">}</span>
<a id="__codelineno-28-19" name="__codelineno-28-19" href="#__codelineno-28-19"></a>
<a id="__codelineno-28-20" name="__codelineno-28-20" href="#__codelineno-28-20"></a> <span class="cm">/* 入栈 */</span>
<a id="__codelineno-28-21" name="__codelineno-28-21" href="#__codelineno-28-21"></a> <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="p">{</span>
<a id="__codelineno-28-22" name="__codelineno-28-22" href="#__codelineno-28-22"></a> <span class="n">stack</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="n">num</span><span class="p">)</span>
<a id="__codelineno-28-23" name="__codelineno-28-23" href="#__codelineno-28-23"></a> <span class="p">}</span>
<a id="__codelineno-28-24" name="__codelineno-28-24" href="#__codelineno-28-24"></a>
<a id="__codelineno-28-25" name="__codelineno-28-25" href="#__codelineno-28-25"></a> <span class="cm">/* 出栈 */</span>
<a id="__codelineno-28-26" name="__codelineno-28-26" href="#__codelineno-28-26"></a> <span class="p">@</span><span class="n">discardableResult</span>
<a id="__codelineno-28-27" name="__codelineno-28-27" href="#__codelineno-28-27"></a> <span class="kd">func</span> <span class="nf">pop</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-28" name="__codelineno-28-28" href="#__codelineno-28-28"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-29" name="__codelineno-28-29" href="#__codelineno-28-29"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;栈为空&quot;</span><span class="p">)</span>
<a id="__codelineno-28-30" name="__codelineno-28-30" href="#__codelineno-28-30"></a> <span class="p">}</span>
<a id="__codelineno-28-31" name="__codelineno-28-31" href="#__codelineno-28-31"></a> <span class="k">return</span> <span class="n">stack</span><span class="p">.</span><span class="bp">removeLast</span><span class="p">()</span>
<a id="__codelineno-28-32" name="__codelineno-28-32" href="#__codelineno-28-32"></a> <span class="p">}</span>
<a id="__codelineno-28-33" name="__codelineno-28-33" href="#__codelineno-28-33"></a>
<a id="__codelineno-28-34" name="__codelineno-28-34" href="#__codelineno-28-34"></a> <span class="cm">/* 访问栈顶元素 */</span>
<a id="__codelineno-28-35" name="__codelineno-28-35" href="#__codelineno-28-35"></a> <span class="kd">func</span> <span class="nf">peek</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-36" name="__codelineno-28-36" href="#__codelineno-28-36"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-37" name="__codelineno-28-37" href="#__codelineno-28-37"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;栈为空&quot;</span><span class="p">)</span>
<a id="__codelineno-28-38" name="__codelineno-28-38" href="#__codelineno-28-38"></a> <span class="p">}</span>
<a id="__codelineno-28-39" name="__codelineno-28-39" href="#__codelineno-28-39"></a> <span class="k">return</span> <span class="n">stack</span><span class="p">.</span><span class="bp">last</span><span class="p">!</span>
<a id="__codelineno-28-40" name="__codelineno-28-40" href="#__codelineno-28-40"></a> <span class="p">}</span>
<a id="__codelineno-28-41" name="__codelineno-28-41" href="#__codelineno-28-41"></a>
<a id="__codelineno-28-42" name="__codelineno-28-42" href="#__codelineno-28-42"></a> <span class="cm">/* 将 List 转化为 Array 并返回 */</span>
<a id="__codelineno-28-43" name="__codelineno-28-43" href="#__codelineno-28-43"></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-28-44" name="__codelineno-28-44" href="#__codelineno-28-44"></a> <span class="n">stack</span>
<a id="__codelineno-28-45" name="__codelineno-28-45" href="#__codelineno-28-45"></a> <span class="p">}</span>
<a id="__codelineno-28-46" name="__codelineno-28-46" href="#__codelineno-28-46"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_stack.zig</span><pre><span></span><code><a id="__codelineno-29-1" name="__codelineno-29-1" href="#__codelineno-29-1"></a><span class="c1">// 基于数组实现的栈</span>
<a id="__codelineno-29-2" name="__codelineno-29-2" href="#__codelineno-29-2"></a><span class="k">fn</span><span class="w"> </span><span class="n">ArrayStack</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-29-3" name="__codelineno-29-3" href="#__codelineno-29-3"></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-29-4" name="__codelineno-29-4" href="#__codelineno-29-4"></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-29-5" name="__codelineno-29-5" href="#__codelineno-29-5"></a>
<a id="__codelineno-29-6" name="__codelineno-29-6" href="#__codelineno-29-6"></a><span class="w"> </span><span class="n">stack</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">ArrayList</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>
<a id="__codelineno-29-7" name="__codelineno-29-7" href="#__codelineno-29-7"></a>
<a id="__codelineno-29-8" name="__codelineno-29-8" href="#__codelineno-29-8"></a><span class="w"> </span><span class="c1">// 构造方法(分配内存+初始化栈)</span>
<a id="__codelineno-29-9" name="__codelineno-29-9" href="#__codelineno-29-9"></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="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-29-10" name="__codelineno-29-10" href="#__codelineno-29-10"></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">stack</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-29-11" name="__codelineno-29-11" href="#__codelineno-29-11"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stack</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">ArrayList</span><span class="p">(</span><span class="n">T</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-29-12" name="__codelineno-29-12" href="#__codelineno-29-12"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-13" name="__codelineno-29-13" href="#__codelineno-29-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-14" name="__codelineno-29-14" href="#__codelineno-29-14"></a>
<a id="__codelineno-29-15" name="__codelineno-29-15" href="#__codelineno-29-15"></a><span class="w"> </span><span class="c1">// 析构方法(释放内存)</span>
<a id="__codelineno-29-16" name="__codelineno-29-16" href="#__codelineno-29-16"></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-29-17" name="__codelineno-29-17" href="#__codelineno-29-17"></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">stack</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-29-18" name="__codelineno-29-18" href="#__codelineno-29-18"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">stack</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-29-19" name="__codelineno-29-19" href="#__codelineno-29-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-20" name="__codelineno-29-20" href="#__codelineno-29-20"></a>
<a id="__codelineno-29-21" name="__codelineno-29-21" href="#__codelineno-29-21"></a><span class="w"> </span><span class="c1">// 获取栈的长度</span>
<a id="__codelineno-29-22" name="__codelineno-29-22" href="#__codelineno-29-22"></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-29-23" name="__codelineno-29-23" href="#__codelineno-29-23"></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">stack</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">.</span><span class="n">len</span><span class="p">;</span>
<a id="__codelineno-29-24" name="__codelineno-29-24" href="#__codelineno-29-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-25" name="__codelineno-29-25" href="#__codelineno-29-25"></a>
<a id="__codelineno-29-26" name="__codelineno-29-26" href="#__codelineno-29-26"></a><span class="w"> </span><span class="c1">// 判断栈是否为空</span>
<a id="__codelineno-29-27" name="__codelineno-29-27" href="#__codelineno-29-27"></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-29-28" name="__codelineno-29-28" href="#__codelineno-29-28"></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-29-29" name="__codelineno-29-29" href="#__codelineno-29-29"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-30" name="__codelineno-29-30" href="#__codelineno-29-30"></a>
<a id="__codelineno-29-31" name="__codelineno-29-31" href="#__codelineno-29-31"></a><span class="w"> </span><span class="c1">// 访问栈顶元素</span>
<a id="__codelineno-29-32" name="__codelineno-29-32" href="#__codelineno-29-32"></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">peek</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-29-33" name="__codelineno-29-33" href="#__codelineno-29-33"></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;栈为空&quot;</span><span class="p">);</span>
<a id="__codelineno-29-34" name="__codelineno-29-34" href="#__codelineno-29-34"></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">stack</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">items</span><span class="p">[</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">1</span><span class="p">];</span>
<a id="__codelineno-29-35" name="__codelineno-29-35" href="#__codelineno-29-35"></a><span class="w"> </span><span class="p">}</span><span class="w"> </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="w"> </span><span class="c1">// 入栈</span>
<a id="__codelineno-29-38" name="__codelineno-29-38" href="#__codelineno-29-38"></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="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-29-39" name="__codelineno-29-39" href="#__codelineno-29-39"></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">stack</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-29-40" name="__codelineno-29-40" href="#__codelineno-29-40"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-29-41" name="__codelineno-29-41" href="#__codelineno-29-41"></a>
<a id="__codelineno-29-42" name="__codelineno-29-42" href="#__codelineno-29-42"></a><span class="w"> </span><span class="c1">// 出栈</span>
<a id="__codelineno-29-43" name="__codelineno-29-43" href="#__codelineno-29-43"></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">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-29-44" name="__codelineno-29-44" href="#__codelineno-29-44"></a><span class="w"> </span><span class="kr">var</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">self</span><span class="p">.</span><span class="n">stack</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">pop</span><span class="p">();</span>
<a id="__codelineno-29-45" name="__codelineno-29-45" href="#__codelineno-29-45"></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-29-46" name="__codelineno-29-46" href="#__codelineno-29-46"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-29-47" name="__codelineno-29-47" href="#__codelineno-29-47"></a>
<a id="__codelineno-29-48" name="__codelineno-29-48" href="#__codelineno-29-48"></a><span class="w"> </span><span class="c1">// 返回 ArrayList</span>
<a id="__codelineno-29-49" name="__codelineno-29-49" href="#__codelineno-29-49"></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">toList</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">std</span><span class="p">.</span><span class="n">ArrayList</span><span class="p">(</span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-29-50" name="__codelineno-29-50" href="#__codelineno-29-50"></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">stack</span><span class="p">.</span><span class="o">?</span><span class="p">;</span>
<a id="__codelineno-29-51" name="__codelineno-29-51" href="#__codelineno-29-51"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-29-52" name="__codelineno-29-52" href="#__codelineno-29-52"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-29-53" name="__codelineno-29-53" href="#__codelineno-29-53"></a><span class="p">}</span>
</code></pre></div>
</div>
</div>
</div>
<h2 id="513">5.1.3. &nbsp; 两种实现对比<a class="headerlink" href="#513" title="Permanent link">&para;</a></h2>
<h3 id="_3">支持操作<a class="headerlink" href="#_3" title="Permanent link">&para;</a></h3>
<p>两种实现都支持栈定义中的各项操作,数组实现额外支持随机访问,但这已经超出栈的定义范畴,一般不会用到。</p>
<h3 id="_4">时间效率<a class="headerlink" href="#_4" title="Permanent link">&para;</a></h3>
<p>在数组(列表)实现中,入栈与出栈操作都是在预先分配好的连续内存中操作,具有很好的缓存本地性,效率很好。然而,如果入栈时超出数组容量,则会触发扩容机制,那么该次入栈操作的时间复杂度为 <span class="arithmatex">\(O(n)\)</span></p>
<p>在链表实现中,链表的扩容非常灵活,不存在上述数组扩容时变慢的问题。然而,入栈操作需要初始化结点对象并修改指针,因而效率不如数组。进一步地思考,如果入栈元素不是 <code>int</code> 而是结点对象,那么就可以省去初始化步骤,从而提升效率。</p>
<p>综上所述,当入栈与出栈操作的元素是基本数据类型(例如 <code>int</code> , <code>double</code> )时,则结论如下:</p>
<ul>
<li>数组实现的栈在触发扩容时会变慢,但由于扩容是低频操作,因此 <strong>总体效率更高</strong></li>
<li>链表实现的栈可以提供 <strong>更加稳定的效率表现</strong></li>
</ul>
<h3 id="_5">空间效率<a class="headerlink" href="#_5" title="Permanent link">&para;</a></h3>
<p>在初始化列表时,系统会给列表分配“初始容量”,该容量可能超过我们的需求。并且扩容机制一般是按照特定倍率(比如 2 倍)进行扩容,扩容后的容量也可能超出我们的需求。因此,<strong>数组实现栈会造成一定的空间浪费</strong></p>
<p>当然,由于结点需要额外存储指针,因此 <strong>链表结点比数组元素占用更大</strong></p>
<p>综上,我们不能简单地确定哪种实现更加省内存,需要 case-by-case 地分析。</p>
<h2 id="514">5.1.4. &nbsp; 栈典型应用<a class="headerlink" href="#514" title="Permanent link">&para;</a></h2>
<ul>
<li><strong>浏览器中的后退与前进、软件中的撤销与反撤销</strong>。每当我们打开新的网页,浏览器就将上一个网页执行入栈,这样我们就可以通过「后退」操作来回到上一页面,后退操作实际上是在执行出栈。如果要同时支持后退和前进,那么则需要两个栈来配合实现。</li>
<li><strong>程序内存管理</strong>。每当调用函数时,系统就会在栈顶添加一个栈帧,用来记录函数的上下文信息。在递归函数中,向下递推会不断执行入栈,向上回溯阶段时出栈。</li>
</ul>
<h2 id="__comments">评论</h2>
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