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5.3.1. &nbsp; 双向队列常用操作
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基于双向链表的实现
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基于数组的实现
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<a href="https://github.com/krahets/hello-algo/tree/main/docs/chapter_stack_and_queue/deque.md" title="编辑此页" class="md-content__button md-icon">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M10 20H6V4h7v5h5v3.1l2-2V8l-6-6H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h4v-2m10.2-7c.1 0 .3.1.4.2l1.3 1.3c.2.2.2.6 0 .8l-1 1-2.1-2.1 1-1c.1-.1.2-.2.4-.2m0 3.9L14.1 23H12v-2.1l6.1-6.1 2.1 2.1Z"/></svg>
</a>
<h1 id="53">5.3. &nbsp; 双向队列<a class="headerlink" href="#53" title="Permanent link">&para;</a></h1>
<p>对于队列，我们仅能在头部删除或在尾部添加元素。然而，「双向队列 Deque」提供了更高的灵活性，允许在头部和尾部执行元素的添加或删除操作。</p>
<p><img alt="双向队列的操作" src="../deque.assets/deque_operations.png" /></p>
<p align="center"> Fig. 双向队列的操作 </p>
<h2 id="531">5.3.1. &nbsp; 双向队列常用操作<a class="headerlink" href="#531" title="Permanent link">&para;</a></h2>
<p>双向队列的常用操作如下表所示，具体的方法名称需要根据所使用的编程语言来确定。</p>
<div class="center-table">
<table>
<thead>
<tr>
<th>方法名</th>
<th>描述</th>
<th>时间复杂度</th>
</tr>
</thead>
<tbody>
<tr>
<td>pushFirst()</td>
<td>将元素添加至队首</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>pushLast()</td>
<td>将元素添加至队尾</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>popFirst()</td>
<td>删除队首元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>popLast()</td>
<td>删除队尾元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>peekFirst()</td>
<td>访问队首元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
<tr>
<td>peekLast()</td>
<td>访问队尾元素</td>
<td><span class="arithmatex">\(O(1)\)</span></td>
</tr>
</tbody>
</table>
</div>
<p>同样地，我们可以直接使用编程语言中已实现的双向队列类。</p>
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<div class="highlight"><span class="filename">deque.java</span><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a><span class="n">Deque</span><span class="o">&lt;</span><span class="n">Integer</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">LinkedList</span><span class="o">&lt;&gt;</span><span class="p">();</span>
<a id="__codelineno-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">/* 元素入队 */</span>
<a id="__codelineno-0-5" name="__codelineno-0-5" href="#__codelineno-0-5"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-0-6" name="__codelineno-0-6" href="#__codelineno-0-6"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-0-7" name="__codelineno-0-7" href="#__codelineno-0-7"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerLast</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<a id="__codelineno-0-8" name="__codelineno-0-8" href="#__codelineno-0-8"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerFirst</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-0-9" name="__codelineno-0-9" href="#__codelineno-0-9"></a><span class="n">deque</span><span class="p">.</span><span class="na">offerFirst</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-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">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">peekFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-0-13" name="__codelineno-0-13" href="#__codelineno-0-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">peekLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-0-14" name="__codelineno-0-14" href="#__codelineno-0-14"></a>
<a id="__codelineno-0-15" name="__codelineno-0-15" href="#__codelineno-0-15"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-0-16" name="__codelineno-0-16" href="#__codelineno-0-16"></a><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">pollFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-0-17" name="__codelineno-0-17" href="#__codelineno-0-17"></a><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">pollLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-0-18" name="__codelineno-0-18" href="#__codelineno-0-18"></a>
<a id="__codelineno-0-19" name="__codelineno-0-19" href="#__codelineno-0-19"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-0-20" name="__codelineno-0-20" href="#__codelineno-0-20"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">size</span><span class="p">();</span>
<a id="__codelineno-0-21" name="__codelineno-0-21" href="#__codelineno-0-21"></a>
<a id="__codelineno-0-22" name="__codelineno-0-22" href="#__codelineno-0-22"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-0-23" name="__codelineno-0-23" href="#__codelineno-0-23"></a><span class="kt">boolean</span><span class="w"> </span><span class="n">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="na">isEmpty</span><span class="p">();</span>
</code></pre></div>
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<div class="highlight"><span class="filename">deque.cpp</span><pre><span></span><code><a id="__codelineno-1-1" name="__codelineno-1-1" href="#__codelineno-1-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-1-2" name="__codelineno-1-2" href="#__codelineno-1-2"></a><span class="n">deque</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-1-3" name="__codelineno-1-3" href="#__codelineno-1-3"></a>
<a id="__codelineno-1-4" name="__codelineno-1-4" href="#__codelineno-1-4"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-1-5" name="__codelineno-1-5" href="#__codelineno-1-5"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-1-6" name="__codelineno-1-6" href="#__codelineno-1-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">5</span><span class="p">);</span>
<a id="__codelineno-1-7" name="__codelineno-1-7" href="#__codelineno-1-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_back</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<a id="__codelineno-1-8" name="__codelineno-1-8" href="#__codelineno-1-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-1-9" name="__codelineno-1-9" href="#__codelineno-1-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">push_front</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-1-10" name="__codelineno-1-10" href="#__codelineno-1-10"></a>
<a id="__codelineno-1-11" name="__codelineno-1-11" href="#__codelineno-1-11"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-1-12" name="__codelineno-1-12" href="#__codelineno-1-12"></a><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">front</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-1-13" name="__codelineno-1-13" href="#__codelineno-1-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">back</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">back</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-1-14" name="__codelineno-1-14" href="#__codelineno-1-14"></a>
<a id="__codelineno-1-15" name="__codelineno-1-15" href="#__codelineno-1-15"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-1-16" name="__codelineno-1-16" href="#__codelineno-1-16"></a><span class="n">deque</span><span class="p">.</span><span class="n">pop_front</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-1-17" name="__codelineno-1-17" href="#__codelineno-1-17"></a><span class="n">deque</span><span class="p">.</span><span class="n">pop_back</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-1-18" name="__codelineno-1-18" href="#__codelineno-1-18"></a>
<a id="__codelineno-1-19" name="__codelineno-1-19" href="#__codelineno-1-19"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-1-20" name="__codelineno-1-20" href="#__codelineno-1-20"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">size</span><span class="p">();</span>
<a id="__codelineno-1-21" name="__codelineno-1-21" href="#__codelineno-1-21"></a>
<a id="__codelineno-1-22" name="__codelineno-1-22" href="#__codelineno-1-22"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-1-23" name="__codelineno-1-23" href="#__codelineno-1-23"></a><span class="kt">bool</span><span class="w"> </span><span class="n">empty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">empty</span><span class="p">();</span>
</code></pre></div>
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<div class="highlight"><span class="filename">deque.py</span><pre><span></span><code><a id="__codelineno-2-1" name="__codelineno-2-1" href="#__codelineno-2-1"></a><span class="c1"># 初始化双向队列</span>
<a id="__codelineno-2-2" name="__codelineno-2-2" href="#__codelineno-2-2"></a><span class="n">deque</span><span class="p">:</span> <span class="n">Deque</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="n">collections</span><span class="o">.</span><span class="n">deque</span><span class="p">()</span>
<a id="__codelineno-2-3" name="__codelineno-2-3" href="#__codelineno-2-3"></a>
<a id="__codelineno-2-4" name="__codelineno-2-4" href="#__codelineno-2-4"></a><span class="c1"># 元素入队</span>
<a id="__codelineno-2-5" name="__codelineno-2-5" href="#__codelineno-2-5"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="c1"># 添加至队尾</span>
<a id="__codelineno-2-6" name="__codelineno-2-6" href="#__codelineno-2-6"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-2-7" name="__codelineno-2-7" href="#__codelineno-2-7"></a><span class="n">deque</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-2-8" name="__codelineno-2-8" href="#__codelineno-2-8"></a><span class="n">deque</span><span class="o">.</span><span class="n">appendleft</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span> <span class="c1"># 添加至队首</span>
<a id="__codelineno-2-9" name="__codelineno-2-9" href="#__codelineno-2-9"></a><span class="n">deque</span><span class="o">.</span><span class="n">appendleft</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-2-10" name="__codelineno-2-10" href="#__codelineno-2-10"></a>
<a id="__codelineno-2-11" name="__codelineno-2-11" href="#__codelineno-2-11"></a><span class="c1"># 访问元素</span>
<a id="__codelineno-2-12" name="__codelineno-2-12" href="#__codelineno-2-12"></a><span class="n">front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="c1"># 队首元素</span>
<a id="__codelineno-2-13" name="__codelineno-2-13" href="#__codelineno-2-13"></a><span class="n">rear</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="c1"># 队尾元素</span>
<a id="__codelineno-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="c1"># 元素出队</span>
<a id="__codelineno-2-16" name="__codelineno-2-16" href="#__codelineno-2-16"></a><span class="n">pop_front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="o">.</span><span class="n">popleft</span><span class="p">()</span> <span class="c1"># 队首元素出队</span>
<a id="__codelineno-2-17" name="__codelineno-2-17" href="#__codelineno-2-17"></a><span class="n">pop_rear</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">deque</span><span class="o">.</span><span class="n">pop</span><span class="p">()</span> <span class="c1"># 队尾元素出队</span>
<a id="__codelineno-2-18" name="__codelineno-2-18" href="#__codelineno-2-18"></a>
<a id="__codelineno-2-19" name="__codelineno-2-19" href="#__codelineno-2-19"></a><span class="c1"># 获取双向队列的长度</span>
<a id="__codelineno-2-20" name="__codelineno-2-20" href="#__codelineno-2-20"></a><span class="n">size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span>
<a id="__codelineno-2-21" name="__codelineno-2-21" href="#__codelineno-2-21"></a>
<a id="__codelineno-2-22" name="__codelineno-2-22" href="#__codelineno-2-22"></a><span class="c1"># 判断双向队列是否为空</span>
<a id="__codelineno-2-23" name="__codelineno-2-23" href="#__codelineno-2-23"></a><span class="n">is_empty</span><span class="p">:</span> <span class="nb">bool</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span> <span class="o">==</span> <span class="mi">0</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque_test.go</span><pre><span></span><code><a id="__codelineno-3-1" name="__codelineno-3-1" href="#__codelineno-3-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-3-2" name="__codelineno-3-2" href="#__codelineno-3-2"></a><span class="c1">// 在 Go 中，将 list 作为双向队列使用</span>
<a id="__codelineno-3-3" name="__codelineno-3-3" href="#__codelineno-3-3"></a><span class="nx">deque</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">list</span><span class="p">.</span><span class="nx">New</span><span class="p">()</span>
<a id="__codelineno-3-4" name="__codelineno-3-4" href="#__codelineno-3-4"></a>
<a id="__codelineno-3-5" name="__codelineno-3-5" href="#__codelineno-3-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-3-6" name="__codelineno-3-6" href="#__codelineno-3-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-3-7" name="__codelineno-3-7" href="#__codelineno-3-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-3-8" name="__codelineno-3-8" href="#__codelineno-3-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-3-9" name="__codelineno-3-9" href="#__codelineno-3-9"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushFront</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-3-10" name="__codelineno-3-10" href="#__codelineno-3-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">PushFront</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-3-11" name="__codelineno-3-11" href="#__codelineno-3-11"></a>
<a id="__codelineno-3-12" name="__codelineno-3-12" href="#__codelineno-3-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-3-13" name="__codelineno-3-13" href="#__codelineno-3-13"></a><span class="nx">front</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-3-14" name="__codelineno-3-14" href="#__codelineno-3-14"></a><span class="nx">rear</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Back</span><span class="p">()</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-3-15" name="__codelineno-3-15" href="#__codelineno-3-15"></a>
<a id="__codelineno-3-16" name="__codelineno-3-16" href="#__codelineno-3-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-3-17" name="__codelineno-3-17" href="#__codelineno-3-17"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">front</span><span class="p">)</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-3-18" name="__codelineno-3-18" href="#__codelineno-3-18"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">rear</span><span class="p">)</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-3-19" name="__codelineno-3-19" href="#__codelineno-3-19"></a>
<a id="__codelineno-3-20" name="__codelineno-3-20" href="#__codelineno-3-20"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-3-21" name="__codelineno-3-21" href="#__codelineno-3-21"></a><span class="nx">size</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span>
<a id="__codelineno-3-22" name="__codelineno-3-22" href="#__codelineno-3-22"></a>
<a id="__codelineno-3-23" name="__codelineno-3-23" href="#__codelineno-3-23"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-3-24" name="__codelineno-3-24" href="#__codelineno-3-24"></a><span class="nx">isEmpty</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.js</span><pre><span></span><code><a id="__codelineno-4-1" name="__codelineno-4-1" href="#__codelineno-4-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-4-2" name="__codelineno-4-2" href="#__codelineno-4-2"></a><span class="c1">// JavaScript 没有内置的双端队列，只能把 Array 当作双端队列来使用</span>
<a id="__codelineno-4-3" name="__codelineno-4-3" href="#__codelineno-4-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-4-4" name="__codelineno-4-4" href="#__codelineno-4-4"></a>
<a id="__codelineno-4-5" name="__codelineno-4-5" href="#__codelineno-4-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-4-6" name="__codelineno-4-6" href="#__codelineno-4-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">2</span><span class="p">);</span>
<a id="__codelineno-4-7" name="__codelineno-4-7" href="#__codelineno-4-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">5</span><span class="p">);</span>
<a id="__codelineno-4-8" name="__codelineno-4-8" href="#__codelineno-4-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">4</span><span class="p">);</span>
<a id="__codelineno-4-9" name="__codelineno-4-9" href="#__codelineno-4-9"></a><span class="c1">// 请注意，由于是数组，unshift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-4-10" name="__codelineno-4-10" href="#__codelineno-4-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-4-11" name="__codelineno-4-11" href="#__codelineno-4-11"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-4-12" name="__codelineno-4-12" href="#__codelineno-4-12"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列 deque = &quot;</span><span class="p">,</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-4-13" name="__codelineno-4-13" href="#__codelineno-4-13"></a>
<a id="__codelineno-4-14" name="__codelineno-4-14" href="#__codelineno-4-14"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-4-15" name="__codelineno-4-15" href="#__codelineno-4-15"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<a id="__codelineno-4-16" name="__codelineno-4-16" href="#__codelineno-4-16"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首元素 peekFirst = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">);</span>
<a id="__codelineno-4-17" name="__codelineno-4-17" href="#__codelineno-4-17"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">];</span>
<a id="__codelineno-4-18" name="__codelineno-4-18" href="#__codelineno-4-18"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾元素 peekLast = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">);</span>
<a id="__codelineno-4-19" name="__codelineno-4-19" href="#__codelineno-4-19"></a>
<a id="__codelineno-4-20" name="__codelineno-4-20" href="#__codelineno-4-20"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-4-21" name="__codelineno-4-21" href="#__codelineno-4-21"></a><span class="c1">// 请注意，由于是数组，shift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-4-22" name="__codelineno-4-22" href="#__codelineno-4-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">shift</span><span class="p">();</span>
<a id="__codelineno-4-23" name="__codelineno-4-23" href="#__codelineno-4-23"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首出队元素 popFront = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;，队首出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-4-24" name="__codelineno-4-24" href="#__codelineno-4-24"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<a id="__codelineno-4-25" name="__codelineno-4-25" href="#__codelineno-4-25"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾出队元素 popBack = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;，队尾出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-4-26" name="__codelineno-4-26" href="#__codelineno-4-26"></a>
<a id="__codelineno-4-27" name="__codelineno-4-27" href="#__codelineno-4-27"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-4-28" name="__codelineno-4-28" href="#__codelineno-4-28"></a><span class="kd">const</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-4-29" name="__codelineno-4-29" href="#__codelineno-4-29"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列长度 size = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">size</span><span class="p">);</span>
<a id="__codelineno-4-30" name="__codelineno-4-30" href="#__codelineno-4-30"></a>
<a id="__codelineno-4-31" name="__codelineno-4-31" href="#__codelineno-4-31"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-4-32" name="__codelineno-4-32" href="#__codelineno-4-32"></a><span class="kd">const</span><span class="w"> </span><span class="nx">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-4-33" name="__codelineno-4-33" href="#__codelineno-4-33"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列是否为空 = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">);</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.ts</span><pre><span></span><code><a id="__codelineno-5-1" name="__codelineno-5-1" href="#__codelineno-5-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-5-2" name="__codelineno-5-2" href="#__codelineno-5-2"></a><span class="c1">// TypeScript 没有内置的双端队列，只能把 Array 当作双端队列来使用</span>
<a id="__codelineno-5-3" name="__codelineno-5-3" href="#__codelineno-5-3"></a><span class="kd">const</span><span class="w"> </span><span class="nx">deque</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-5-4" name="__codelineno-5-4" href="#__codelineno-5-4"></a>
<a id="__codelineno-5-5" name="__codelineno-5-5" href="#__codelineno-5-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-5-6" name="__codelineno-5-6" href="#__codelineno-5-6"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">2</span><span class="p">);</span>
<a id="__codelineno-5-7" name="__codelineno-5-7" href="#__codelineno-5-7"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">5</span><span class="p">);</span>
<a id="__codelineno-5-8" name="__codelineno-5-8" href="#__codelineno-5-8"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="mf">4</span><span class="p">);</span>
<a id="__codelineno-5-9" name="__codelineno-5-9" href="#__codelineno-5-9"></a><span class="c1">// 请注意，由于是数组，unshift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-5-10" name="__codelineno-5-10" href="#__codelineno-5-10"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">3</span><span class="p">);</span>
<a id="__codelineno-5-11" name="__codelineno-5-11" href="#__codelineno-5-11"></a><span class="nx">deque</span><span class="p">.</span><span class="nx">unshift</span><span class="p">(</span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-5-12" name="__codelineno-5-12" href="#__codelineno-5-12"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列 deque = &quot;</span><span class="p">,</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-5-13" name="__codelineno-5-13" href="#__codelineno-5-13"></a>
<a id="__codelineno-5-14" name="__codelineno-5-14" href="#__codelineno-5-14"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-5-15" name="__codelineno-5-15" href="#__codelineno-5-15"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekFirst</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="mf">0</span><span class="p">];</span>
<a id="__codelineno-5-16" name="__codelineno-5-16" href="#__codelineno-5-16"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首元素 peekFirst = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">);</span>
<a id="__codelineno-5-17" name="__codelineno-5-17" href="#__codelineno-5-17"></a><span class="kd">const</span><span class="w"> </span><span class="nx">peekLast</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">[</span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">];</span>
<a id="__codelineno-5-18" name="__codelineno-5-18" href="#__codelineno-5-18"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾元素 peekLast = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">);</span>
<a id="__codelineno-5-19" name="__codelineno-5-19" href="#__codelineno-5-19"></a>
<a id="__codelineno-5-20" name="__codelineno-5-20" href="#__codelineno-5-20"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-5-21" name="__codelineno-5-21" href="#__codelineno-5-21"></a><span class="c1">// 请注意，由于是数组，shift() 方法的时间复杂度为 O(n)</span>
<a id="__codelineno-5-22" name="__codelineno-5-22" href="#__codelineno-5-22"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popFront</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">shift</span><span class="p">()</span><span class="w"> </span><span class="kr">as</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span>
<a id="__codelineno-5-23" name="__codelineno-5-23" href="#__codelineno-5-23"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队首出队元素 popFront = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popFront</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;，队首出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-5-24" name="__codelineno-5-24" href="#__codelineno-5-24"></a><span class="kd">const</span><span class="w"> </span><span class="nx">popBack</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">pop</span><span class="p">()</span><span class="w"> </span><span class="kr">as</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span>
<a id="__codelineno-5-25" name="__codelineno-5-25" href="#__codelineno-5-25"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;队尾出队元素 popBack = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">popBack</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s2">&quot;，队尾出队后 deque = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">deque</span><span class="p">);</span>
<a id="__codelineno-5-26" name="__codelineno-5-26" href="#__codelineno-5-26"></a>
<a id="__codelineno-5-27" name="__codelineno-5-27" href="#__codelineno-5-27"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-5-28" name="__codelineno-5-28" href="#__codelineno-5-28"></a><span class="kd">const</span><span class="w"> </span><span class="nx">size</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">deque</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-5-29" name="__codelineno-5-29" href="#__codelineno-5-29"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列长度 size = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">size</span><span class="p">);</span>
<a id="__codelineno-5-30" name="__codelineno-5-30" href="#__codelineno-5-30"></a>
<a id="__codelineno-5-31" name="__codelineno-5-31" href="#__codelineno-5-31"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-5-32" name="__codelineno-5-32" href="#__codelineno-5-32"></a><span class="kd">const</span><span class="w"> </span><span class="nx">isEmpty</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">size</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-5-33" name="__codelineno-5-33" href="#__codelineno-5-33"></a><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s2">&quot;双向队列是否为空 = &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">);</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.c</span><pre><span></span><code><a id="__codelineno-6-1" name="__codelineno-6-1" href="#__codelineno-6-1"></a><span class="c1">// C 未提供内置双向队列</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.cs</span><pre><span></span><code><a id="__codelineno-7-1" name="__codelineno-7-1" href="#__codelineno-7-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-7-2" name="__codelineno-7-2" href="#__codelineno-7-2"></a><span class="c1">// 在 C# 中，将链表 LinkedList 看作双向队列来使用</span>
<a id="__codelineno-7-3" name="__codelineno-7-3" href="#__codelineno-7-3"></a><span class="n">LinkedList</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">LinkedList</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="p">();</span>
<a id="__codelineno-7-4" name="__codelineno-7-4" href="#__codelineno-7-4"></a>
<a id="__codelineno-7-5" name="__codelineno-7-5" href="#__codelineno-7-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-7-6" name="__codelineno-7-6" href="#__codelineno-7-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">2</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队尾</span>
<a id="__codelineno-7-7" name="__codelineno-7-7" href="#__codelineno-7-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">5</span><span class="p">);</span>
<a id="__codelineno-7-8" name="__codelineno-7-8" href="#__codelineno-7-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddLast</span><span class="p">(</span><span class="m">4</span><span class="p">);</span>
<a id="__codelineno-7-9" name="__codelineno-7-9" href="#__codelineno-7-9"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddFirst</span><span class="p">(</span><span class="m">3</span><span class="p">);</span><span class="w"> </span><span class="c1">// 添加至队首</span>
<a id="__codelineno-7-10" name="__codelineno-7-10" href="#__codelineno-7-10"></a><span class="n">deque</span><span class="p">.</span><span class="n">AddFirst</span><span class="p">(</span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-7-11" name="__codelineno-7-11" href="#__codelineno-7-11"></a>
<a id="__codelineno-7-12" name="__codelineno-7-12" href="#__codelineno-7-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-7-13" name="__codelineno-7-13" href="#__codelineno-7-13"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">First</span><span class="p">.</span><span class="n">Value</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首元素</span>
<a id="__codelineno-7-14" name="__codelineno-7-14" href="#__codelineno-7-14"></a><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Last</span><span class="p">.</span><span class="n">Value</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队尾元素</span>
<a id="__codelineno-7-15" name="__codelineno-7-15" href="#__codelineno-7-15"></a>
<a id="__codelineno-7-16" name="__codelineno-7-16" href="#__codelineno-7-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-7-17" name="__codelineno-7-17" href="#__codelineno-7-17"></a><span class="n">deque</span><span class="p">.</span><span class="n">RemoveFirst</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队首元素出队</span>
<a id="__codelineno-7-18" name="__codelineno-7-18" href="#__codelineno-7-18"></a><span class="n">deque</span><span class="p">.</span><span class="n">RemoveLast</span><span class="p">();</span><span class="w"> </span><span class="c1">// 队尾元素出队</span>
<a id="__codelineno-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">/* 获取双向队列的长度 */</span>
<a id="__codelineno-7-21" name="__codelineno-7-21" href="#__codelineno-7-21"></a><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Count</span><span class="p">;</span>
<a id="__codelineno-7-22" name="__codelineno-7-22" href="#__codelineno-7-22"></a>
<a id="__codelineno-7-23" name="__codelineno-7-23" href="#__codelineno-7-23"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-7-24" name="__codelineno-7-24" href="#__codelineno-7-24"></a><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="p">.</span><span class="n">Count</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.swift</span><pre><span></span><code><a id="__codelineno-8-1" name="__codelineno-8-1" href="#__codelineno-8-1"></a><span class="cm">/* 初始化双向队列 */</span>
<a id="__codelineno-8-2" name="__codelineno-8-2" href="#__codelineno-8-2"></a><span class="c1">// Swift 没有内置的双向队列类，可以把 Array 当作双向队列来使用</span>
<a id="__codelineno-8-3" name="__codelineno-8-3" href="#__codelineno-8-3"></a><span class="kd">var</span> <span class="nv">deque</span><span class="p">:</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="p">=</span> <span class="p">[]</span>
<a id="__codelineno-8-4" name="__codelineno-8-4" href="#__codelineno-8-4"></a>
<a id="__codelineno-8-5" name="__codelineno-8-5" href="#__codelineno-8-5"></a><span class="cm">/* 元素入队 */</span>
<a id="__codelineno-8-6" name="__codelineno-8-6" href="#__codelineno-8-6"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="c1">// 添加至队尾</span>
<a id="__codelineno-8-7" name="__codelineno-8-7" href="#__codelineno-8-7"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span>
<a id="__codelineno-8-8" name="__codelineno-8-8" href="#__codelineno-8-8"></a><span class="n">deque</span><span class="p">.</span><span class="n">append</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<a id="__codelineno-8-9" name="__codelineno-8-9" href="#__codelineno-8-9"></a><span class="n">deque</span><span class="p">.</span><span class="bp">insert</span><span class="p">(</span><span class="mi">3</span><span class="p">,</span> <span class="n">at</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span> <span class="c1">// 添加至队首</span>
<a id="__codelineno-8-10" name="__codelineno-8-10" href="#__codelineno-8-10"></a><span class="n">deque</span><span class="p">.</span><span class="bp">insert</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="n">at</span><span class="p">:</span> <span class="mi">0</span><span class="p">)</span>
<a id="__codelineno-8-11" name="__codelineno-8-11" href="#__codelineno-8-11"></a>
<a id="__codelineno-8-12" name="__codelineno-8-12" href="#__codelineno-8-12"></a><span class="cm">/* 访问元素 */</span>
<a id="__codelineno-8-13" name="__codelineno-8-13" href="#__codelineno-8-13"></a><span class="kd">let</span> <span class="nv">peekFirst</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">first</span><span class="p">!</span> <span class="c1">// 队首元素</span>
<a id="__codelineno-8-14" name="__codelineno-8-14" href="#__codelineno-8-14"></a><span class="kd">let</span> <span class="nv">peekLast</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">last</span><span class="p">!</span> <span class="c1">// 队尾元素</span>
<a id="__codelineno-8-15" name="__codelineno-8-15" href="#__codelineno-8-15"></a>
<a id="__codelineno-8-16" name="__codelineno-8-16" href="#__codelineno-8-16"></a><span class="cm">/* 元素出队 */</span>
<a id="__codelineno-8-17" name="__codelineno-8-17" href="#__codelineno-8-17"></a><span class="c1">// 使用 Array 模拟时 popFirst 的复杂度为 O(n)</span>
<a id="__codelineno-8-18" name="__codelineno-8-18" href="#__codelineno-8-18"></a><span class="kd">let</span> <span class="nv">popFirst</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="n">removeFirst</span><span class="p">()</span> <span class="c1">// 队首元素出队</span>
<a id="__codelineno-8-19" name="__codelineno-8-19" href="#__codelineno-8-19"></a><span class="kd">let</span> <span class="nv">popLast</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">removeLast</span><span class="p">()</span> <span class="c1">// 队尾元素出队</span>
<a id="__codelineno-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">/* 获取双向队列的长度 */</span>
<a id="__codelineno-8-22" name="__codelineno-8-22" href="#__codelineno-8-22"></a><span class="kd">let</span> <span class="nv">size</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-8-23" name="__codelineno-8-23" href="#__codelineno-8-23"></a>
<a id="__codelineno-8-24" name="__codelineno-8-24" href="#__codelineno-8-24"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-8-25" name="__codelineno-8-25" href="#__codelineno-8-25"></a><span class="kd">let</span> <span class="nv">isEmpty</span> <span class="p">=</span> <span class="n">deque</span><span class="p">.</span><span class="bp">isEmpty</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">deque.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="532">5.3.2. &nbsp; 双向队列实现 *<a class="headerlink" href="#532" title="Permanent link">&para;</a></h2>
<p>双向队列的实现与队列类似，可以选择链表或数组作为底层数据结构。</p>
<h3 id="_1">基于双向链表的实现<a class="headerlink" href="#_1" title="Permanent link">&para;</a></h3>
<p>回顾上一节内容，我们使用普通单向链表来实现队列，因为它可以方便地删除头节点（对应出队操作）和在尾节点后添加新节点（对应入队操作）。</p>
<p>对于双向队列而言，头部和尾部都可以执行入队和出队操作。换句话说，双向队列需要实现另一个对称方向的操作。为此，我们采用「双向链表」作为双向队列的底层数据结构。</p>
<p>我们将双向链表的头节点和尾节点视为双向队列的队首和队尾，同时实现在两端添加和删除节点的功能。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="2:5"><input checked="checked" id="__tabbed_2_1" name="__tabbed_2" type="radio" /><input id="__tabbed_2_2" name="__tabbed_2" type="radio" /><input id="__tabbed_2_3" name="__tabbed_2" type="radio" /><input id="__tabbed_2_4" name="__tabbed_2" type="radio" /><input id="__tabbed_2_5" name="__tabbed_2" type="radio" /><div class="tabbed-labels"><label for="__tabbed_2_1">LinkedListDeque</label><label for="__tabbed_2_2">pushLast()</label><label for="__tabbed_2_3">pushFirst()</label><label for="__tabbed_2_4">popLast()</label><label for="__tabbed_2_5">popFirst()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><img alt="基于链表实现双向队列的入队出队操作" src="../deque.assets/linkedlist_deque.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_deque_push_last" src="../deque.assets/linkedlist_deque_push_last.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_deque_push_first" src="../deque.assets/linkedlist_deque_push_first.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_deque_pop_last" src="../deque.assets/linkedlist_deque_pop_last.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="linkedlist_deque_pop_first" src="../deque.assets/linkedlist_deque_pop_first.png" /></p>
</div>
</div>
</div>
<p>以下是具体实现代码。</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_deque.java</span><pre><span></span><code><a id="__codelineno-10-1" name="__codelineno-10-1" href="#__codelineno-10-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-10-2" name="__codelineno-10-2" href="#__codelineno-10-2"></a><span class="kd">class</span> <span class="nc">ListNode</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="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-10-4" name="__codelineno-10-4" href="#__codelineno-10-4"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用（指针）</span>
<a id="__codelineno-10-5" name="__codelineno-10-5" href="#__codelineno-10-5"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用（指针）</span>
<a id="__codelineno-10-6" name="__codelineno-10-6" href="#__codelineno-10-6"></a>
<a id="__codelineno-10-7" name="__codelineno-10-7" href="#__codelineno-10-7"></a><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-8" name="__codelineno-10-8" href="#__codelineno-10-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="na">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-10-9" name="__codelineno-10-9" href="#__codelineno-10-9"></a><span class="w"> </span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-10" name="__codelineno-10-10" href="#__codelineno-10-10"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-11" name="__codelineno-10-11" href="#__codelineno-10-11"></a><span class="p">}</span>
<a id="__codelineno-10-12" name="__codelineno-10-12" href="#__codelineno-10-12"></a>
<a id="__codelineno-10-13" name="__codelineno-10-13" href="#__codelineno-10-13"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-10-14" name="__codelineno-10-14" href="#__codelineno-10-14"></a><span class="kd">class</span> <span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-15" name="__codelineno-10-15" href="#__codelineno-10-15"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ，尾节点 rear</span>
<a id="__codelineno-10-16" name="__codelineno-10-16" href="#__codelineno-10-16"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-10-17" name="__codelineno-10-17" href="#__codelineno-10-17"></a>
<a id="__codelineno-10-18" name="__codelineno-10-18" href="#__codelineno-10-18"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-19" name="__codelineno-10-19" href="#__codelineno-10-19"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-20" name="__codelineno-10-20" href="#__codelineno-10-20"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-21" name="__codelineno-10-21" href="#__codelineno-10-21"></a>
<a id="__codelineno-10-22" name="__codelineno-10-22" href="#__codelineno-10-22"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-10-23" name="__codelineno-10-23" href="#__codelineno-10-23"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-24" name="__codelineno-10-24" href="#__codelineno-10-24"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-10-25" name="__codelineno-10-25" href="#__codelineno-10-25"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-26" name="__codelineno-10-26" href="#__codelineno-10-26"></a>
<a id="__codelineno-10-27" name="__codelineno-10-27" href="#__codelineno-10-27"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-10-28" name="__codelineno-10-28" href="#__codelineno-10-28"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-29" name="__codelineno-10-29" href="#__codelineno-10-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-10-30" name="__codelineno-10-30" href="#__codelineno-10-30"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-31" name="__codelineno-10-31" href="#__codelineno-10-31"></a>
<a id="__codelineno-10-32" name="__codelineno-10-32" href="#__codelineno-10-32"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-10-33" name="__codelineno-10-33" href="#__codelineno-10-33"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-34" name="__codelineno-10-34" href="#__codelineno-10-34"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-10-35" name="__codelineno-10-35" href="#__codelineno-10-35"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-10-36" name="__codelineno-10-36" href="#__codelineno-10-36"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-10-37" name="__codelineno-10-37" href="#__codelineno-10-37"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-10-38" name="__codelineno-10-38" href="#__codelineno-10-38"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-10-39" name="__codelineno-10-39" href="#__codelineno-10-39"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-40" name="__codelineno-10-40" href="#__codelineno-10-40"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-10-41" name="__codelineno-10-41" href="#__codelineno-10-41"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-10-42" name="__codelineno-10-42" href="#__codelineno-10-42"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-10-43" name="__codelineno-10-43" href="#__codelineno-10-43"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-10-44" name="__codelineno-10-44" href="#__codelineno-10-44"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-10-45" name="__codelineno-10-45" href="#__codelineno-10-45"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-46" name="__codelineno-10-46" href="#__codelineno-10-46"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-10-47" name="__codelineno-10-47" href="#__codelineno-10-47"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-10-48" name="__codelineno-10-48" href="#__codelineno-10-48"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-10-49" name="__codelineno-10-49" href="#__codelineno-10-49"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-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="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-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>
<a id="__codelineno-10-54" name="__codelineno-10-54" href="#__codelineno-10-54"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-10-55" name="__codelineno-10-55" href="#__codelineno-10-55"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-56" name="__codelineno-10-56" href="#__codelineno-10-56"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-10-57" name="__codelineno-10-57" href="#__codelineno-10-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-58" name="__codelineno-10-58" href="#__codelineno-10-58"></a>
<a id="__codelineno-10-59" name="__codelineno-10-59" href="#__codelineno-10-59"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-10-60" name="__codelineno-10-60" href="#__codelineno-10-60"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-61" name="__codelineno-10-61" href="#__codelineno-10-61"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-10-62" name="__codelineno-10-62" href="#__codelineno-10-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-63" name="__codelineno-10-63" href="#__codelineno-10-63"></a>
<a id="__codelineno-10-64" name="__codelineno-10-64" href="#__codelineno-10-64"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-10-65" name="__codelineno-10-65" href="#__codelineno-10-65"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="n">Integer</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="kt">boolean</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-66" name="__codelineno-10-66" href="#__codelineno-10-66"></a><span class="w"> </span><span class="c1">// 若队列为空，直接返回 null</span>
<a id="__codelineno-10-67" name="__codelineno-10-67" href="#__codelineno-10-67"></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-10-68" name="__codelineno-10-68" href="#__codelineno-10-68"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-69" name="__codelineno-10-69" href="#__codelineno-10-69"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-10-70" name="__codelineno-10-70" href="#__codelineno-10-70"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-10-71" name="__codelineno-10-71" href="#__codelineno-10-71"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-72" name="__codelineno-10-72" href="#__codelineno-10-72"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-10-73" name="__codelineno-10-73" href="#__codelineno-10-73"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-10-74" name="__codelineno-10-74" href="#__codelineno-10-74"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">next</span><span class="p">;</span>
<a id="__codelineno-10-75" name="__codelineno-10-75" href="#__codelineno-10-75"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-76" name="__codelineno-10-76" href="#__codelineno-10-76"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-77" name="__codelineno-10-77" href="#__codelineno-10-77"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-78" name="__codelineno-10-78" href="#__codelineno-10-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-79" name="__codelineno-10-79" href="#__codelineno-10-79"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-10-80" name="__codelineno-10-80" href="#__codelineno-10-80"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-10-81" name="__codelineno-10-81" href="#__codelineno-10-81"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-82" name="__codelineno-10-82" href="#__codelineno-10-82"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-10-83" name="__codelineno-10-83" href="#__codelineno-10-83"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-10-84" name="__codelineno-10-84" href="#__codelineno-10-84"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">prev</span><span class="p">;</span>
<a id="__codelineno-10-85" name="__codelineno-10-85" href="#__codelineno-10-85"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-86" name="__codelineno-10-86" href="#__codelineno-10-86"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="na">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-87" name="__codelineno-10-87" href="#__codelineno-10-87"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-10-88" name="__codelineno-10-88" href="#__codelineno-10-88"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-89" name="__codelineno-10-89" href="#__codelineno-10-89"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-10-90" name="__codelineno-10-90" href="#__codelineno-10-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-91" name="__codelineno-10-91" href="#__codelineno-10-91"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-10-92" name="__codelineno-10-92" href="#__codelineno-10-92"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-10-93" name="__codelineno-10-93" href="#__codelineno-10-93"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-94" name="__codelineno-10-94" href="#__codelineno-10-94"></a>
<a id="__codelineno-10-95" name="__codelineno-10-95" href="#__codelineno-10-95"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-10-96" name="__codelineno-10-96" href="#__codelineno-10-96"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">Integer</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-97" name="__codelineno-10-97" href="#__codelineno-10-97"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-10-98" name="__codelineno-10-98" href="#__codelineno-10-98"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-99" name="__codelineno-10-99" href="#__codelineno-10-99"></a>
<a id="__codelineno-10-100" name="__codelineno-10-100" href="#__codelineno-10-100"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-10-101" name="__codelineno-10-101" href="#__codelineno-10-101"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">Integer</span><span class="w"> </span><span class="nf">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-102" name="__codelineno-10-102" href="#__codelineno-10-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-10-103" name="__codelineno-10-103" href="#__codelineno-10-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-104" name="__codelineno-10-104" href="#__codelineno-10-104"></a>
<a id="__codelineno-10-105" name="__codelineno-10-105" href="#__codelineno-10-105"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-10-106" name="__codelineno-10-106" href="#__codelineno-10-106"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">Integer</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-107" name="__codelineno-10-107" href="#__codelineno-10-107"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-10-108" name="__codelineno-10-108" href="#__codelineno-10-108"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-109" name="__codelineno-10-109" href="#__codelineno-10-109"></a>
<a id="__codelineno-10-110" name="__codelineno-10-110" href="#__codelineno-10-110"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-10-111" name="__codelineno-10-111" href="#__codelineno-10-111"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="n">Integer</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-112" name="__codelineno-10-112" href="#__codelineno-10-112"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="na">val</span><span class="p">;</span>
<a id="__codelineno-10-113" name="__codelineno-10-113" href="#__codelineno-10-113"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-114" name="__codelineno-10-114" href="#__codelineno-10-114"></a>
<a id="__codelineno-10-115" name="__codelineno-10-115" href="#__codelineno-10-115"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-10-116" name="__codelineno-10-116" href="#__codelineno-10-116"></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-10-117" name="__codelineno-10-117" href="#__codelineno-10-117"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-10-118" name="__codelineno-10-118" href="#__codelineno-10-118"></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-10-119" name="__codelineno-10-119" href="#__codelineno-10-119"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="na">length</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-10-120" name="__codelineno-10-120" href="#__codelineno-10-120"></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-10-121" name="__codelineno-10-121" href="#__codelineno-10-121"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="na">next</span><span class="p">;</span>
<a id="__codelineno-10-122" name="__codelineno-10-122" href="#__codelineno-10-122"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-123" name="__codelineno-10-123" href="#__codelineno-10-123"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-10-124" name="__codelineno-10-124" href="#__codelineno-10-124"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-10-125" name="__codelineno-10-125" href="#__codelineno-10-125"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.cpp</span><pre><span></span><code><a id="__codelineno-11-1" name="__codelineno-11-1" href="#__codelineno-11-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-11-2" name="__codelineno-11-2" href="#__codelineno-11-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">DoublyListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-3" name="__codelineno-11-3" href="#__codelineno-11-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-11-4" name="__codelineno-11-4" href="#__codelineno-11-4"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点指针</span>
<a id="__codelineno-11-5" name="__codelineno-11-5" href="#__codelineno-11-5"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点指针</span>
<a id="__codelineno-11-6" name="__codelineno-11-6" href="#__codelineno-11-6"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">val</span><span class="p">(</span><span class="n">val</span><span class="p">),</span><span class="w"> </span><span class="n">prev</span><span class="p">(</span><span class="k">nullptr</span><span class="p">),</span><span class="w"> </span><span class="n">next</span><span class="p">(</span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-7" name="__codelineno-11-7" href="#__codelineno-11-7"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-8" name="__codelineno-11-8" href="#__codelineno-11-8"></a><span class="p">};</span>
<a id="__codelineno-11-9" name="__codelineno-11-9" href="#__codelineno-11-9"></a>
<a id="__codelineno-11-10" name="__codelineno-11-10" href="#__codelineno-11-10"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-11-11" name="__codelineno-11-11" href="#__codelineno-11-11"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-12" name="__codelineno-11-12" href="#__codelineno-11-12"></a><span class="w"> </span><span class="k">private</span><span class="o">:</span>
<a id="__codelineno-11-13" name="__codelineno-11-13" href="#__codelineno-11-13"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ，尾节点 rear</span>
<a id="__codelineno-11-14" name="__codelineno-11-14" href="#__codelineno-11-14"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-11-15" name="__codelineno-11-15" href="#__codelineno-11-15"></a>
<a id="__codelineno-11-16" name="__codelineno-11-16" href="#__codelineno-11-16"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-11-17" name="__codelineno-11-17" href="#__codelineno-11-17"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-11-18" name="__codelineno-11-18" href="#__codelineno-11-18"></a><span class="w"> </span><span class="n">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">front</span><span class="p">(</span><span class="k">nullptr</span><span class="p">),</span><span class="w"> </span><span class="n">rear</span><span class="p">(</span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-19" name="__codelineno-11-19" href="#__codelineno-11-19"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-20" name="__codelineno-11-20" href="#__codelineno-11-20"></a>
<a id="__codelineno-11-21" name="__codelineno-11-21" href="#__codelineno-11-21"></a><span class="w"> </span><span class="cm">/* 析构方法 */</span>
<a id="__codelineno-11-22" name="__codelineno-11-22" href="#__codelineno-11-22"></a><span class="w"> </span><span class="o">~</span><span class="n">LinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-23" name="__codelineno-11-23" href="#__codelineno-11-23"></a><span class="w"> </span><span class="c1">// 遍历链表删除节点，释放内存</span>
<a id="__codelineno-11-24" name="__codelineno-11-24" href="#__codelineno-11-24"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">pre</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">cur</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-11-25" name="__codelineno-11-25" href="#__codelineno-11-25"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">cur</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-26" name="__codelineno-11-26" href="#__codelineno-11-26"></a><span class="w"> </span><span class="n">pre</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">cur</span><span class="p">;</span>
<a id="__codelineno-11-27" name="__codelineno-11-27" href="#__codelineno-11-27"></a><span class="w"> </span><span class="n">cur</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">cur</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-11-28" name="__codelineno-11-28" href="#__codelineno-11-28"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">pre</span><span class="p">;</span>
<a id="__codelineno-11-29" name="__codelineno-11-29" href="#__codelineno-11-29"></a><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="p">}</span>
<a id="__codelineno-11-31" name="__codelineno-11-31" href="#__codelineno-11-31"></a>
<a id="__codelineno-11-32" name="__codelineno-11-32" href="#__codelineno-11-32"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-11-33" name="__codelineno-11-33" href="#__codelineno-11-33"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-34" name="__codelineno-11-34" href="#__codelineno-11-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-11-35" name="__codelineno-11-35" href="#__codelineno-11-35"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-36" name="__codelineno-11-36" href="#__codelineno-11-36"></a>
<a id="__codelineno-11-37" name="__codelineno-11-37" href="#__codelineno-11-37"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-11-38" name="__codelineno-11-38" href="#__codelineno-11-38"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-39" name="__codelineno-11-39" href="#__codelineno-11-39"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-11-40" name="__codelineno-11-40" href="#__codelineno-11-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-41" name="__codelineno-11-41" href="#__codelineno-11-41"></a>
<a id="__codelineno-11-42" name="__codelineno-11-42" href="#__codelineno-11-42"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-11-43" name="__codelineno-11-43" href="#__codelineno-11-43"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-44" name="__codelineno-11-44" href="#__codelineno-11-44"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">DoublyListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-11-45" name="__codelineno-11-45" href="#__codelineno-11-45"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-11-46" name="__codelineno-11-46" href="#__codelineno-11-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-11-47" name="__codelineno-11-47" href="#__codelineno-11-47"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-11-48" name="__codelineno-11-48" href="#__codelineno-11-48"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-11-49" name="__codelineno-11-49" href="#__codelineno-11-49"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-50" name="__codelineno-11-50" href="#__codelineno-11-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-11-51" name="__codelineno-11-51" href="#__codelineno-11-51"></a><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-11-52" name="__codelineno-11-52" href="#__codelineno-11-52"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-11-53" name="__codelineno-11-53" href="#__codelineno-11-53"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-11-54" name="__codelineno-11-54" href="#__codelineno-11-54"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-11-55" name="__codelineno-11-55" href="#__codelineno-11-55"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-56" name="__codelineno-11-56" href="#__codelineno-11-56"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-11-57" name="__codelineno-11-57" href="#__codelineno-11-57"></a><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-11-58" name="__codelineno-11-58" href="#__codelineno-11-58"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-11-59" name="__codelineno-11-59" href="#__codelineno-11-59"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-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="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-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>
<a id="__codelineno-11-64" name="__codelineno-11-64" href="#__codelineno-11-64"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-11-65" name="__codelineno-11-65" href="#__codelineno-11-65"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-66" name="__codelineno-11-66" href="#__codelineno-11-66"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-11-67" name="__codelineno-11-67" href="#__codelineno-11-67"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-68" name="__codelineno-11-68" href="#__codelineno-11-68"></a>
<a id="__codelineno-11-69" name="__codelineno-11-69" href="#__codelineno-11-69"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-11-70" name="__codelineno-11-70" href="#__codelineno-11-70"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-71" name="__codelineno-11-71" href="#__codelineno-11-71"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-11-72" name="__codelineno-11-72" href="#__codelineno-11-72"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-73" name="__codelineno-11-73" href="#__codelineno-11-73"></a>
<a id="__codelineno-11-74" name="__codelineno-11-74" href="#__codelineno-11-74"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-11-75" name="__codelineno-11-75" href="#__codelineno-11-75"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-76" name="__codelineno-11-76" href="#__codelineno-11-76"></a><span class="w"> </span><span class="c1">// 若队列为空，直接返回 -1</span>
<a id="__codelineno-11-77" name="__codelineno-11-77" href="#__codelineno-11-77"></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-11-78" name="__codelineno-11-78" href="#__codelineno-11-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<a id="__codelineno-11-79" name="__codelineno-11-79" href="#__codelineno-11-79"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-11-80" name="__codelineno-11-80" href="#__codelineno-11-80"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-11-81" name="__codelineno-11-81" href="#__codelineno-11-81"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-82" name="__codelineno-11-82" href="#__codelineno-11-82"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-11-83" name="__codelineno-11-83" href="#__codelineno-11-83"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-11-84" name="__codelineno-11-84" href="#__codelineno-11-84"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-11-85" name="__codelineno-11-85" href="#__codelineno-11-85"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-86" name="__codelineno-11-86" href="#__codelineno-11-86"></a><span class="w"> </span><span class="n">fNext</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-11-87" name="__codelineno-11-87" href="#__codelineno-11-87"></a><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-11-88" name="__codelineno-11-88" href="#__codelineno-11-88"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-11-89" name="__codelineno-11-89" href="#__codelineno-11-89"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-90" name="__codelineno-11-90" href="#__codelineno-11-90"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-11-91" name="__codelineno-11-91" href="#__codelineno-11-91"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-11-92" name="__codelineno-11-92" href="#__codelineno-11-92"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-93" name="__codelineno-11-93" href="#__codelineno-11-93"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-11-94" name="__codelineno-11-94" href="#__codelineno-11-94"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-11-95" name="__codelineno-11-95" href="#__codelineno-11-95"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-11-96" name="__codelineno-11-96" href="#__codelineno-11-96"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-97" name="__codelineno-11-97" href="#__codelineno-11-97"></a><span class="w"> </span><span class="n">rPrev</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-11-98" name="__codelineno-11-98" href="#__codelineno-11-98"></a><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">nullptr</span><span class="p">;</span>
<a id="__codelineno-11-99" name="__codelineno-11-99" href="#__codelineno-11-99"></a><span class="w"> </span><span class="k">delete</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-11-100" name="__codelineno-11-100" href="#__codelineno-11-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-101" name="__codelineno-11-101" href="#__codelineno-11-101"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-11-102" name="__codelineno-11-102" href="#__codelineno-11-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-103" name="__codelineno-11-103" href="#__codelineno-11-103"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-11-104" name="__codelineno-11-104" href="#__codelineno-11-104"></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-11-105" name="__codelineno-11-105" href="#__codelineno-11-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-106" name="__codelineno-11-106" href="#__codelineno-11-106"></a>
<a id="__codelineno-11-107" name="__codelineno-11-107" href="#__codelineno-11-107"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-11-108" name="__codelineno-11-108" href="#__codelineno-11-108"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-109" name="__codelineno-11-109" href="#__codelineno-11-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-11-110" name="__codelineno-11-110" href="#__codelineno-11-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-111" name="__codelineno-11-111" href="#__codelineno-11-111"></a>
<a id="__codelineno-11-112" name="__codelineno-11-112" href="#__codelineno-11-112"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-11-113" name="__codelineno-11-113" href="#__codelineno-11-113"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-114" name="__codelineno-11-114" href="#__codelineno-11-114"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-11-115" name="__codelineno-11-115" href="#__codelineno-11-115"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-116" name="__codelineno-11-116" href="#__codelineno-11-116"></a>
<a id="__codelineno-11-117" name="__codelineno-11-117" href="#__codelineno-11-117"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-11-118" name="__codelineno-11-118" href="#__codelineno-11-118"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-119" name="__codelineno-11-119" href="#__codelineno-11-119"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="mi">-1</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-11-120" name="__codelineno-11-120" href="#__codelineno-11-120"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-121" name="__codelineno-11-121" href="#__codelineno-11-121"></a>
<a id="__codelineno-11-122" name="__codelineno-11-122" href="#__codelineno-11-122"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-11-123" name="__codelineno-11-123" href="#__codelineno-11-123"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-124" name="__codelineno-11-124" href="#__codelineno-11-124"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="mi">-1</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-11-125" name="__codelineno-11-125" href="#__codelineno-11-125"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-126" name="__codelineno-11-126" href="#__codelineno-11-126"></a>
<a id="__codelineno-11-127" name="__codelineno-11-127" href="#__codelineno-11-127"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-11-128" name="__codelineno-11-128" href="#__codelineno-11-128"></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-11-129" name="__codelineno-11-129" href="#__codelineno-11-129"></a><span class="w"> </span><span class="n">DoublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-11-130" name="__codelineno-11-130" href="#__codelineno-11-130"></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-11-131" name="__codelineno-11-131" href="#__codelineno-11-131"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">size</span><span class="p">();</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-11-132" name="__codelineno-11-132" href="#__codelineno-11-132"></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-11-133" name="__codelineno-11-133" href="#__codelineno-11-133"></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-11-134" name="__codelineno-11-134" href="#__codelineno-11-134"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-135" name="__codelineno-11-135" href="#__codelineno-11-135"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-11-136" name="__codelineno-11-136" href="#__codelineno-11-136"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-11-137" name="__codelineno-11-137" href="#__codelineno-11-137"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.py</span><pre><span></span><code><a id="__codelineno-12-1" name="__codelineno-12-1" href="#__codelineno-12-1"></a><span class="k">class</span> <span class="nc">ListNode</span><span class="p">:</span>
<a id="__codelineno-12-2" name="__codelineno-12-2" href="#__codelineno-12-2"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;双向链表节点&quot;&quot;&quot;</span>
<a id="__codelineno-12-3" name="__codelineno-12-3" href="#__codelineno-12-3"></a>
<a id="__codelineno-12-4" name="__codelineno-12-4" href="#__codelineno-12-4"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-5" name="__codelineno-12-5" href="#__codelineno-12-5"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-12-6" name="__codelineno-12-6" href="#__codelineno-12-6"></a> <span class="bp">self</span><span class="o">.</span><span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="n">val</span>
<a id="__codelineno-12-7" name="__codelineno-12-7" href="#__codelineno-12-7"></a> <span class="bp">self</span><span class="o">.</span><span class="n">next</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 后继节点引用（指针）</span>
<a id="__codelineno-12-8" name="__codelineno-12-8" href="#__codelineno-12-8"></a> <span class="bp">self</span><span class="o">.</span><span class="n">prev</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 前驱节点引用（指针）</span>
<a id="__codelineno-12-9" name="__codelineno-12-9" href="#__codelineno-12-9"></a>
<a id="__codelineno-12-10" name="__codelineno-12-10" href="#__codelineno-12-10"></a><span class="k">class</span> <span class="nc">LinkedListDeque</span><span class="p">:</span>
<a id="__codelineno-12-11" name="__codelineno-12-11" href="#__codelineno-12-11"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;基于双向链表实现的双向队列&quot;&quot;&quot;</span>
<a id="__codelineno-12-12" name="__codelineno-12-12" href="#__codelineno-12-12"></a>
<a id="__codelineno-12-13" name="__codelineno-12-13" href="#__codelineno-12-13"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-14" name="__codelineno-12-14" href="#__codelineno-12-14"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-12-15" name="__codelineno-12-15" href="#__codelineno-12-15"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 头节点 front</span>
<a id="__codelineno-12-16" name="__codelineno-12-16" href="#__codelineno-12-16"></a> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="kc">None</span> <span class="c1"># 尾节点 rear</span>
<a id="__codelineno-12-17" name="__codelineno-12-17" href="#__codelineno-12-17"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1"># 双向队列的长度</span>
<a id="__codelineno-12-18" name="__codelineno-12-18" href="#__codelineno-12-18"></a>
<a id="__codelineno-12-19" name="__codelineno-12-19" href="#__codelineno-12-19"></a> <span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-20" name="__codelineno-12-20" href="#__codelineno-12-20"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的长度&quot;&quot;&quot;</span>
<a id="__codelineno-12-21" name="__codelineno-12-21" href="#__codelineno-12-21"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span>
<a id="__codelineno-12-22" name="__codelineno-12-22" href="#__codelineno-12-22"></a>
<a id="__codelineno-12-23" name="__codelineno-12-23" href="#__codelineno-12-23"></a> <span class="k">def</span> <span class="nf">is_empty</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">bool</span><span class="p">:</span>
<a id="__codelineno-12-24" name="__codelineno-12-24" href="#__codelineno-12-24"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;判断双向队列是否为空&quot;&quot;&quot;</span>
<a id="__codelineno-12-25" name="__codelineno-12-25" href="#__codelineno-12-25"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()</span> <span class="o">==</span> <span class="mi">0</span>
<a id="__codelineno-12-26" name="__codelineno-12-26" href="#__codelineno-12-26"></a>
<a id="__codelineno-12-27" name="__codelineno-12-27" href="#__codelineno-12-27"></a> <span class="k">def</span> <span class="nf">push</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">is_front</span><span class="p">:</span> <span class="nb">bool</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-28" name="__codelineno-12-28" href="#__codelineno-12-28"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;入队操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-29" name="__codelineno-12-29" href="#__codelineno-12-29"></a> <span class="n">node</span> <span class="o">=</span> <span class="n">ListNode</span><span class="p">(</span><span class="n">num</span><span class="p">)</span>
<a id="__codelineno-12-30" name="__codelineno-12-30" href="#__codelineno-12-30"></a> <span class="c1"># 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-12-31" name="__codelineno-12-31" href="#__codelineno-12-31"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-32" name="__codelineno-12-32" href="#__codelineno-12-32"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-33" name="__codelineno-12-33" href="#__codelineno-12-33"></a> <span class="c1"># 队首入队操作</span>
<a id="__codelineno-12-34" name="__codelineno-12-34" href="#__codelineno-12-34"></a> <span class="k">elif</span> <span class="n">is_front</span><span class="p">:</span>
<a id="__codelineno-12-35" name="__codelineno-12-35" href="#__codelineno-12-35"></a> <span class="c1"># 将 node 添加至链表头部</span>
<a id="__codelineno-12-36" name="__codelineno-12-36" href="#__codelineno-12-36"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-37" name="__codelineno-12-37" href="#__codelineno-12-37"></a> <span class="n">node</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">front</span>
<a id="__codelineno-12-38" name="__codelineno-12-38" href="#__codelineno-12-38"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span> <span class="o">=</span> <span class="n">node</span> <span class="c1"># 更新头节点</span>
<a id="__codelineno-12-39" name="__codelineno-12-39" href="#__codelineno-12-39"></a> <span class="c1"># 队尾入队操作</span>
<a id="__codelineno-12-40" name="__codelineno-12-40" href="#__codelineno-12-40"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-41" name="__codelineno-12-41" href="#__codelineno-12-41"></a> <span class="c1"># 将 node 添加至链表尾部</span>
<a id="__codelineno-12-42" name="__codelineno-12-42" href="#__codelineno-12-42"></a> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="n">node</span>
<a id="__codelineno-12-43" name="__codelineno-12-43" href="#__codelineno-12-43"></a> <span class="n">node</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span>
<a id="__codelineno-12-44" name="__codelineno-12-44" href="#__codelineno-12-44"></a> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span> <span class="o">=</span> <span class="n">node</span> <span class="c1"># 更新尾节点</span>
<a id="__codelineno-12-45" name="__codelineno-12-45" href="#__codelineno-12-45"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">+=</span> <span class="mi">1</span> <span class="c1"># 更新队列长度</span>
<a id="__codelineno-12-46" name="__codelineno-12-46" href="#__codelineno-12-46"></a>
<a id="__codelineno-12-47" name="__codelineno-12-47" href="#__codelineno-12-47"></a> <span class="k">def</span> <span class="nf">push_first</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-48" name="__codelineno-12-48" href="#__codelineno-12-48"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首入队&quot;&quot;&quot;</span>
<a id="__codelineno-12-49" name="__codelineno-12-49" href="#__codelineno-12-49"></a> <span class="bp">self</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span> <span class="kc">True</span><span class="p">)</span>
<a id="__codelineno-12-50" name="__codelineno-12-50" href="#__codelineno-12-50"></a>
<a id="__codelineno-12-51" name="__codelineno-12-51" href="#__codelineno-12-51"></a> <span class="k">def</span> <span class="nf">push_last</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-52" name="__codelineno-12-52" href="#__codelineno-12-52"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾入队&quot;&quot;&quot;</span>
<a id="__codelineno-12-53" name="__codelineno-12-53" href="#__codelineno-12-53"></a> <span class="bp">self</span><span class="o">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span> <span class="kc">False</span><span class="p">)</span>
<a id="__codelineno-12-54" name="__codelineno-12-54" href="#__codelineno-12-54"></a>
<a id="__codelineno-12-55" name="__codelineno-12-55" href="#__codelineno-12-55"></a> <span class="k">def</span> <span class="nf">pop</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">is_front</span><span class="p">:</span> <span class="nb">bool</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-56" name="__codelineno-12-56" href="#__codelineno-12-56"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;出队操作&quot;&quot;&quot;</span>
<a id="__codelineno-12-57" name="__codelineno-12-57" href="#__codelineno-12-57"></a> <span class="c1"># 若队列为空，直接返回 None</span>
<a id="__codelineno-12-58" name="__codelineno-12-58" href="#__codelineno-12-58"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-12-59" name="__codelineno-12-59" href="#__codelineno-12-59"></a> <span class="k">return</span> <span class="kc">None</span>
<a id="__codelineno-12-60" name="__codelineno-12-60" href="#__codelineno-12-60"></a> <span class="c1"># 队首出队操作</span>
<a id="__codelineno-12-61" name="__codelineno-12-61" href="#__codelineno-12-61"></a> <span class="k">if</span> <span class="n">is_front</span><span class="p">:</span>
<a id="__codelineno-12-62" name="__codelineno-12-62" href="#__codelineno-12-62"></a> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="o">.</span><span class="n">val</span> <span class="c1"># 暂存头节点值</span>
<a id="__codelineno-12-63" name="__codelineno-12-63" href="#__codelineno-12-63"></a> <span class="c1"># 删除头节点</span>
<a id="__codelineno-12-64" name="__codelineno-12-64" href="#__codelineno-12-64"></a> <span class="n">fnext</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="o">.</span><span class="n">next</span>
<a id="__codelineno-12-65" name="__codelineno-12-65" href="#__codelineno-12-65"></a> <span class="k">if</span> <span class="n">fnext</span> <span class="o">!=</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-66" name="__codelineno-12-66" href="#__codelineno-12-66"></a> <span class="n">fnext</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-67" name="__codelineno-12-67" href="#__codelineno-12-67"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-68" name="__codelineno-12-68" href="#__codelineno-12-68"></a> <span class="bp">self</span><span class="o">.</span><span class="n">front</span> <span class="o">=</span> <span class="n">fnext</span> <span class="c1"># 更新头节点</span>
<a id="__codelineno-12-69" name="__codelineno-12-69" href="#__codelineno-12-69"></a> <span class="c1"># 队尾出队操作</span>
<a id="__codelineno-12-70" name="__codelineno-12-70" href="#__codelineno-12-70"></a> <span class="k">else</span><span class="p">:</span>
<a id="__codelineno-12-71" name="__codelineno-12-71" href="#__codelineno-12-71"></a> <span class="n">val</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="o">.</span><span class="n">val</span> <span class="c1"># 暂存尾节点值</span>
<a id="__codelineno-12-72" name="__codelineno-12-72" href="#__codelineno-12-72"></a> <span class="c1"># 删除尾节点</span>
<a id="__codelineno-12-73" name="__codelineno-12-73" href="#__codelineno-12-73"></a> <span class="n">rprev</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="o">.</span><span class="n">prev</span>
<a id="__codelineno-12-74" name="__codelineno-12-74" href="#__codelineno-12-74"></a> <span class="k">if</span> <span class="n">rprev</span> <span class="o">!=</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-12-75" name="__codelineno-12-75" href="#__codelineno-12-75"></a> <span class="n">rprev</span><span class="o">.</span><span class="n">next</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-76" name="__codelineno-12-76" href="#__codelineno-12-76"></a> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="o">.</span><span class="n">prev</span> <span class="o">=</span> <span class="kc">None</span>
<a id="__codelineno-12-77" name="__codelineno-12-77" href="#__codelineno-12-77"></a> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span> <span class="o">=</span> <span class="n">rprev</span> <span class="c1"># 更新尾节点</span>
<a id="__codelineno-12-78" name="__codelineno-12-78" href="#__codelineno-12-78"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">-=</span> <span class="mi">1</span> <span class="c1"># 更新队列长度</span>
<a id="__codelineno-12-79" name="__codelineno-12-79" href="#__codelineno-12-79"></a> <span class="k">return</span> <span class="n">val</span>
<a id="__codelineno-12-80" name="__codelineno-12-80" href="#__codelineno-12-80"></a>
<a id="__codelineno-12-81" name="__codelineno-12-81" href="#__codelineno-12-81"></a> <span class="k">def</span> <span class="nf">pop_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-82" name="__codelineno-12-82" href="#__codelineno-12-82"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首出队&quot;&quot;&quot;</span>
<a id="__codelineno-12-83" name="__codelineno-12-83" href="#__codelineno-12-83"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">True</span><span class="p">)</span>
<a id="__codelineno-12-84" name="__codelineno-12-84" href="#__codelineno-12-84"></a>
<a id="__codelineno-12-85" name="__codelineno-12-85" href="#__codelineno-12-85"></a> <span class="k">def</span> <span class="nf">pop_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-86" name="__codelineno-12-86" href="#__codelineno-12-86"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾出队&quot;&quot;&quot;</span>
<a id="__codelineno-12-87" name="__codelineno-12-87" href="#__codelineno-12-87"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">False</span><span class="p">)</span>
<a id="__codelineno-12-88" name="__codelineno-12-88" href="#__codelineno-12-88"></a>
<a id="__codelineno-12-89" name="__codelineno-12-89" href="#__codelineno-12-89"></a> <span class="k">def</span> <span class="nf">peek_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-90" name="__codelineno-12-90" href="#__codelineno-12-90"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队首元素&quot;&quot;&quot;</span>
<a id="__codelineno-12-91" name="__codelineno-12-91" href="#__codelineno-12-91"></a> <span class="k">return</span> <span class="kc">None</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">()</span> <span class="k">else</span> <span class="bp">self</span><span class="o">.</span><span class="n">front</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-92" name="__codelineno-12-92" href="#__codelineno-12-92"></a>
<a id="__codelineno-12-93" name="__codelineno-12-93" href="#__codelineno-12-93"></a> <span class="k">def</span> <span class="nf">peek_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-12-94" name="__codelineno-12-94" href="#__codelineno-12-94"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队尾元素&quot;&quot;&quot;</span>
<a id="__codelineno-12-95" name="__codelineno-12-95" href="#__codelineno-12-95"></a> <span class="k">return</span> <span class="kc">None</span> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">()</span> <span class="k">else</span> <span class="bp">self</span><span class="o">.</span><span class="n">rear</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-96" name="__codelineno-12-96" href="#__codelineno-12-96"></a>
<a id="__codelineno-12-97" name="__codelineno-12-97" href="#__codelineno-12-97"></a> <span class="k">def</span> <span class="nf">to_array</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]:</span>
<a id="__codelineno-12-98" name="__codelineno-12-98" href="#__codelineno-12-98"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;返回数组用于打印&quot;&quot;&quot;</span>
<a id="__codelineno-12-99" name="__codelineno-12-99" href="#__codelineno-12-99"></a> <span class="n">node</span><span class="p">:</span> <span class="n">ListNode</span> <span class="o">|</span> <span class="kc">None</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">front</span>
<a id="__codelineno-12-100" name="__codelineno-12-100" href="#__codelineno-12-100"></a> <span class="n">res</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">*</span> <span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()</span>
<a id="__codelineno-12-101" name="__codelineno-12-101" href="#__codelineno-12-101"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">size</span><span class="p">()):</span>
<a id="__codelineno-12-102" name="__codelineno-12-102" href="#__codelineno-12-102"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="o">=</span> <span class="n">node</span><span class="o">.</span><span class="n">val</span>
<a id="__codelineno-12-103" name="__codelineno-12-103" href="#__codelineno-12-103"></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-12-104" name="__codelineno-12-104" href="#__codelineno-12-104"></a> <span class="k">return</span> <span class="n">res</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.go</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="cm">/* 基于双向链表实现的双向队列 */</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">linkedListDeque</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</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">/* 初始化双端队列 */</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">newLinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">linkedListDeque</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">/* 队首元素入队 */</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">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">value</span><span class="w"> </span><span class="kt">any</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">PushFront</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">/* 队尾元素入队 */</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">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">value</span><span class="w"> </span><span class="kt">any</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-21" name="__codelineno-13-21" href="#__codelineno-13-21"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">PushBack</span><span class="p">(</span><span class="nx">value</span><span class="p">)</span>
<a id="__codelineno-13-22" name="__codelineno-13-22" href="#__codelineno-13-22"></a><span class="p">}</span>
<a id="__codelineno-13-23" name="__codelineno-13-23" href="#__codelineno-13-23"></a>
<a id="__codelineno-13-24" name="__codelineno-13-24" href="#__codelineno-13-24"></a><span class="cm">/* 队首元素出队 */</span>
<a id="__codelineno-13-25" name="__codelineno-13-25" href="#__codelineno-13-25"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-26" name="__codelineno-13-26" href="#__codelineno-13-26"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-27" name="__codelineno-13-27" href="#__codelineno-13-27"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-28" name="__codelineno-13-28" href="#__codelineno-13-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-29" name="__codelineno-13-29" href="#__codelineno-13-29"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span>
<a id="__codelineno-13-30" name="__codelineno-13-30" href="#__codelineno-13-30"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span>
<a id="__codelineno-13-31" name="__codelineno-13-31" href="#__codelineno-13-31"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-13-32" name="__codelineno-13-32" href="#__codelineno-13-32"></a><span class="p">}</span>
<a id="__codelineno-13-33" name="__codelineno-13-33" href="#__codelineno-13-33"></a>
<a id="__codelineno-13-34" name="__codelineno-13-34" href="#__codelineno-13-34"></a><span class="cm">/* 队尾元素出队 */</span>
<a id="__codelineno-13-35" name="__codelineno-13-35" href="#__codelineno-13-35"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-36" name="__codelineno-13-36" href="#__codelineno-13-36"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-37" name="__codelineno-13-37" href="#__codelineno-13-37"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-38" name="__codelineno-13-38" href="#__codelineno-13-38"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-39" name="__codelineno-13-39" href="#__codelineno-13-39"></a><span class="w"> </span><span class="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-13-40" name="__codelineno-13-40" href="#__codelineno-13-40"></a><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Remove</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span>
<a id="__codelineno-13-41" name="__codelineno-13-41" href="#__codelineno-13-41"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-13-42" name="__codelineno-13-42" href="#__codelineno-13-42"></a><span class="p">}</span>
<a id="__codelineno-13-43" name="__codelineno-13-43" href="#__codelineno-13-43"></a>
<a id="__codelineno-13-44" name="__codelineno-13-44" href="#__codelineno-13-44"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-13-45" name="__codelineno-13-45" href="#__codelineno-13-45"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-46" name="__codelineno-13-46" href="#__codelineno-13-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="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-13-47" name="__codelineno-13-47" href="#__codelineno-13-47"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-48" name="__codelineno-13-48" href="#__codelineno-13-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-49" name="__codelineno-13-49" href="#__codelineno-13-49"></a><span class="w"> </span><span class="nx">e</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Front</span><span class="p">()</span>
<a id="__codelineno-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">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-13-51" name="__codelineno-13-51" href="#__codelineno-13-51"></a><span class="p">}</span>
<a id="__codelineno-13-52" name="__codelineno-13-52" href="#__codelineno-13-52"></a>
<a id="__codelineno-13-53" name="__codelineno-13-53" href="#__codelineno-13-53"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-13-54" name="__codelineno-13-54" href="#__codelineno-13-54"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-55" name="__codelineno-13-55" href="#__codelineno-13-55"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-56" name="__codelineno-13-56" href="#__codelineno-13-56"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-13-57" name="__codelineno-13-57" href="#__codelineno-13-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-13-58" name="__codelineno-13-58" href="#__codelineno-13-58"></a><span class="w"> </span><span class="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-13-59" name="__codelineno-13-59" href="#__codelineno-13-59"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">e</span><span class="p">.</span><span class="nx">Value</span>
<a id="__codelineno-13-60" name="__codelineno-13-60" href="#__codelineno-13-60"></a><span class="p">}</span>
<a id="__codelineno-13-61" name="__codelineno-13-61" href="#__codelineno-13-61"></a>
<a id="__codelineno-13-62" name="__codelineno-13-62" href="#__codelineno-13-62"></a><span class="cm">/* 获取队列的长度 */</span>
<a id="__codelineno-13-63" name="__codelineno-13-63" href="#__codelineno-13-63"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-64" name="__codelineno-13-64" href="#__codelineno-13-64"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span>
<a id="__codelineno-13-65" name="__codelineno-13-65" href="#__codelineno-13-65"></a><span class="p">}</span>
<a id="__codelineno-13-66" name="__codelineno-13-66" href="#__codelineno-13-66"></a>
<a id="__codelineno-13-67" name="__codelineno-13-67" href="#__codelineno-13-67"></a><span class="cm">/* 判断队列是否为空 */</span>
<a id="__codelineno-13-68" name="__codelineno-13-68" href="#__codelineno-13-68"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-69" name="__codelineno-13-69" href="#__codelineno-13-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">Len</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
<a id="__codelineno-13-70" name="__codelineno-13-70" href="#__codelineno-13-70"></a><span class="p">}</span>
<a id="__codelineno-13-71" name="__codelineno-13-71" href="#__codelineno-13-71"></a>
<a id="__codelineno-13-72" name="__codelineno-13-72" href="#__codelineno-13-72"></a><span class="cm">/* 获取 List 用于打印 */</span>
<a id="__codelineno-13-73" name="__codelineno-13-73" href="#__codelineno-13-73"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">s</span><span class="w"> </span><span class="o">*</span><span class="nx">linkedListDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">toList</span><span class="p">()</span><span class="w"> </span><span class="o">*</span><span class="nx">list</span><span class="p">.</span><span class="nx">List</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-13-74" name="__codelineno-13-74" href="#__codelineno-13-74"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">s</span><span class="p">.</span><span class="nx">data</span>
<a id="__codelineno-13-75" name="__codelineno-13-75" href="#__codelineno-13-75"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.js</span><pre><span></span><code><a id="__codelineno-14-1" name="__codelineno-14-1" href="#__codelineno-14-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-14-2" name="__codelineno-14-2" href="#__codelineno-14-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-3" name="__codelineno-14-3" href="#__codelineno-14-3"></a><span class="w"> </span><span class="nx">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用 (指针)</span>
<a id="__codelineno-14-4" name="__codelineno-14-4" href="#__codelineno-14-4"></a><span class="w"> </span><span class="nx">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用 (指针)</span>
<a id="__codelineno-14-5" name="__codelineno-14-5" href="#__codelineno-14-5"></a><span class="w"> </span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-14-6" name="__codelineno-14-6" href="#__codelineno-14-6"></a>
<a id="__codelineno-14-7" name="__codelineno-14-7" href="#__codelineno-14-7"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-8" name="__codelineno-14-8" href="#__codelineno-14-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-14-9" name="__codelineno-14-9" href="#__codelineno-14-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-10" name="__codelineno-14-10" href="#__codelineno-14-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-11" name="__codelineno-14-11" href="#__codelineno-14-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-12" name="__codelineno-14-12" href="#__codelineno-14-12"></a><span class="p">}</span>
<a id="__codelineno-14-13" name="__codelineno-14-13" href="#__codelineno-14-13"></a>
<a id="__codelineno-14-14" name="__codelineno-14-14" href="#__codelineno-14-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-14-15" name="__codelineno-14-15" href="#__codelineno-14-15"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-16" name="__codelineno-14-16" href="#__codelineno-14-16"></a><span class="w"> </span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-14-17" name="__codelineno-14-17" href="#__codelineno-14-17"></a><span class="w"> </span><span class="err">#</span><span class="nx">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-14-18" name="__codelineno-14-18" href="#__codelineno-14-18"></a><span class="w"> </span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-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="kr">constructor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-21" name="__codelineno-14-21" href="#__codelineno-14-21"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-22" name="__codelineno-14-22" href="#__codelineno-14-22"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-23" name="__codelineno-14-23" href="#__codelineno-14-23"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-14-24" name="__codelineno-14-24" href="#__codelineno-14-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-25" name="__codelineno-14-25" href="#__codelineno-14-25"></a>
<a id="__codelineno-14-26" name="__codelineno-14-26" href="#__codelineno-14-26"></a><span class="w"> </span><span class="cm">/* 队尾入队操作 */</span>
<a id="__codelineno-14-27" name="__codelineno-14-27" href="#__codelineno-14-27"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-28" name="__codelineno-14-28" href="#__codelineno-14-28"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-14-29" name="__codelineno-14-29" href="#__codelineno-14-29"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-14-30" name="__codelineno-14-30" href="#__codelineno-14-30"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-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">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-14-33" name="__codelineno-14-33" href="#__codelineno-14-33"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-34" name="__codelineno-14-34" href="#__codelineno-14-34"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-14-35" name="__codelineno-14-35" href="#__codelineno-14-35"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-14-36" name="__codelineno-14-36" href="#__codelineno-14-36"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">;</span>
<a id="__codelineno-14-37" name="__codelineno-14-37" href="#__codelineno-14-37"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-14-38" name="__codelineno-14-38" href="#__codelineno-14-38"></a><span class="w"> </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">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-14-40" name="__codelineno-14-40" href="#__codelineno-14-40"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-41" name="__codelineno-14-41" href="#__codelineno-14-41"></a>
<a id="__codelineno-14-42" name="__codelineno-14-42" href="#__codelineno-14-42"></a><span class="w"> </span><span class="cm">/* 队首入队操作 */</span>
<a id="__codelineno-14-43" name="__codelineno-14-43" href="#__codelineno-14-43"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-44" name="__codelineno-14-44" href="#__codelineno-14-44"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-14-45" name="__codelineno-14-45" href="#__codelineno-14-45"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-14-46" name="__codelineno-14-46" href="#__codelineno-14-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-47" name="__codelineno-14-47" href="#__codelineno-14-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-14-48" name="__codelineno-14-48" href="#__codelineno-14-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-14-49" name="__codelineno-14-49" href="#__codelineno-14-49"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-50" name="__codelineno-14-50" href="#__codelineno-14-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-14-51" name="__codelineno-14-51" href="#__codelineno-14-51"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-14-52" name="__codelineno-14-52" href="#__codelineno-14-52"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-14-53" name="__codelineno-14-53" href="#__codelineno-14-53"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-14-54" name="__codelineno-14-54" href="#__codelineno-14-54"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-55" name="__codelineno-14-55" href="#__codelineno-14-55"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-14-56" name="__codelineno-14-56" href="#__codelineno-14-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-57" name="__codelineno-14-57" href="#__codelineno-14-57"></a>
<a id="__codelineno-14-58" name="__codelineno-14-58" href="#__codelineno-14-58"></a><span class="w"> </span><span class="cm">/* 队尾出队操作 */</span>
<a id="__codelineno-14-59" name="__codelineno-14-59" href="#__codelineno-14-59"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-60" name="__codelineno-14-60" href="#__codelineno-14-60"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-61" name="__codelineno-14-61" href="#__codelineno-14-61"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-62" name="__codelineno-14-62" href="#__codelineno-14-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-63" name="__codelineno-14-63" href="#__codelineno-14-63"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-14-64" name="__codelineno-14-64" href="#__codelineno-14-64"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-14-65" name="__codelineno-14-65" href="#__codelineno-14-65"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="p">;</span>
<a id="__codelineno-14-66" name="__codelineno-14-66" href="#__codelineno-14-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-67" name="__codelineno-14-67" href="#__codelineno-14-67"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-68" name="__codelineno-14-68" href="#__codelineno-14-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-69" name="__codelineno-14-69" href="#__codelineno-14-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-70" name="__codelineno-14-70" href="#__codelineno-14-70"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-14-71" name="__codelineno-14-71" href="#__codelineno-14-71"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-14-72" name="__codelineno-14-72" href="#__codelineno-14-72"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-14-73" name="__codelineno-14-73" href="#__codelineno-14-73"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-74" name="__codelineno-14-74" href="#__codelineno-14-74"></a>
<a id="__codelineno-14-75" name="__codelineno-14-75" href="#__codelineno-14-75"></a><span class="w"> </span><span class="cm">/* 队首出队操作 */</span>
<a id="__codelineno-14-76" name="__codelineno-14-76" href="#__codelineno-14-76"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-77" name="__codelineno-14-77" href="#__codelineno-14-77"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-78" name="__codelineno-14-78" href="#__codelineno-14-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-79" name="__codelineno-14-79" href="#__codelineno-14-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-80" name="__codelineno-14-80" href="#__codelineno-14-80"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-14-81" name="__codelineno-14-81" href="#__codelineno-14-81"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-14-82" name="__codelineno-14-82" href="#__codelineno-14-82"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-14-83" name="__codelineno-14-83" href="#__codelineno-14-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-84" name="__codelineno-14-84" href="#__codelineno-14-84"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-85" name="__codelineno-14-85" href="#__codelineno-14-85"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-14-86" name="__codelineno-14-86" href="#__codelineno-14-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-87" name="__codelineno-14-87" href="#__codelineno-14-87"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-14-88" name="__codelineno-14-88" href="#__codelineno-14-88"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-14-89" name="__codelineno-14-89" href="#__codelineno-14-89"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-14-90" name="__codelineno-14-90" href="#__codelineno-14-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-91" name="__codelineno-14-91" href="#__codelineno-14-91"></a>
<a id="__codelineno-14-92" name="__codelineno-14-92" href="#__codelineno-14-92"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-14-93" name="__codelineno-14-93" href="#__codelineno-14-93"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-94" name="__codelineno-14-94" href="#__codelineno-14-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-14-95" name="__codelineno-14-95" href="#__codelineno-14-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-96" name="__codelineno-14-96" href="#__codelineno-14-96"></a>
<a id="__codelineno-14-97" name="__codelineno-14-97" href="#__codelineno-14-97"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-14-98" name="__codelineno-14-98" href="#__codelineno-14-98"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-99" name="__codelineno-14-99" href="#__codelineno-14-99"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="kc">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-14-100" name="__codelineno-14-100" href="#__codelineno-14-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-101" name="__codelineno-14-101" href="#__codelineno-14-101"></a>
<a id="__codelineno-14-102" name="__codelineno-14-102" href="#__codelineno-14-102"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-14-103" name="__codelineno-14-103" href="#__codelineno-14-103"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-104" name="__codelineno-14-104" href="#__codelineno-14-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-14-105" name="__codelineno-14-105" href="#__codelineno-14-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-106" name="__codelineno-14-106" href="#__codelineno-14-106"></a>
<a id="__codelineno-14-107" name="__codelineno-14-107" href="#__codelineno-14-107"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-14-108" name="__codelineno-14-108" href="#__codelineno-14-108"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-109" name="__codelineno-14-109" href="#__codelineno-14-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-14-110" name="__codelineno-14-110" href="#__codelineno-14-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-111" name="__codelineno-14-111" href="#__codelineno-14-111"></a>
<a id="__codelineno-14-112" name="__codelineno-14-112" href="#__codelineno-14-112"></a><span class="w"> </span><span class="cm">/* 打印双向队列 */</span>
<a id="__codelineno-14-113" name="__codelineno-14-113" href="#__codelineno-14-113"></a><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-114" name="__codelineno-14-114" href="#__codelineno-14-114"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">arr</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-14-115" name="__codelineno-14-115" href="#__codelineno-14-115"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-14-116" name="__codelineno-14-116" href="#__codelineno-14-116"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-14-117" name="__codelineno-14-117" href="#__codelineno-14-117"></a><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">temp</span><span class="p">.</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-14-118" name="__codelineno-14-118" href="#__codelineno-14-118"></a><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-14-119" name="__codelineno-14-119" href="#__codelineno-14-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-120" name="__codelineno-14-120" href="#__codelineno-14-120"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;[&#39;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s1">&#39;]&#39;</span><span class="p">);</span>
<a id="__codelineno-14-121" name="__codelineno-14-121" href="#__codelineno-14-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-14-122" name="__codelineno-14-122" href="#__codelineno-14-122"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.ts</span><pre><span></span><code><a id="__codelineno-15-1" name="__codelineno-15-1" href="#__codelineno-15-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-15-2" name="__codelineno-15-2" href="#__codelineno-15-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-3" name="__codelineno-15-3" href="#__codelineno-15-3"></a><span class="w"> </span><span class="nx">prev</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用 (指针)</span>
<a id="__codelineno-15-4" name="__codelineno-15-4" href="#__codelineno-15-4"></a><span class="w"> </span><span class="nx">next</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用 (指针)</span>
<a id="__codelineno-15-5" name="__codelineno-15-5" href="#__codelineno-15-5"></a><span class="w"> </span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-15-6" name="__codelineno-15-6" href="#__codelineno-15-6"></a>
<a id="__codelineno-15-7" name="__codelineno-15-7" href="#__codelineno-15-7"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-8" name="__codelineno-15-8" href="#__codelineno-15-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">val</span><span class="p">;</span>
<a id="__codelineno-15-9" name="__codelineno-15-9" href="#__codelineno-15-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-10" name="__codelineno-15-10" href="#__codelineno-15-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-11" name="__codelineno-15-11" href="#__codelineno-15-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-12" name="__codelineno-15-12" href="#__codelineno-15-12"></a><span class="p">}</span>
<a id="__codelineno-15-13" name="__codelineno-15-13" href="#__codelineno-15-13"></a>
<a id="__codelineno-15-14" name="__codelineno-15-14" href="#__codelineno-15-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-15-15" name="__codelineno-15-15" href="#__codelineno-15-15"></a><span class="kd">class</span><span class="w"> </span><span class="nx">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-16" name="__codelineno-15-16" href="#__codelineno-15-16"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">front</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-15-17" name="__codelineno-15-17" href="#__codelineno-15-17"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">rear</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-15-18" name="__codelineno-15-18" href="#__codelineno-15-18"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">queSize</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-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="kr">constructor</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-21" name="__codelineno-15-21" href="#__codelineno-15-21"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-22" name="__codelineno-15-22" href="#__codelineno-15-22"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-23" name="__codelineno-15-23" href="#__codelineno-15-23"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-15-24" name="__codelineno-15-24" href="#__codelineno-15-24"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-25" name="__codelineno-15-25" href="#__codelineno-15-25"></a>
<a id="__codelineno-15-26" name="__codelineno-15-26" href="#__codelineno-15-26"></a><span class="w"> </span><span class="cm">/* 队尾入队操作 */</span>
<a id="__codelineno-15-27" name="__codelineno-15-27" href="#__codelineno-15-27"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-28" name="__codelineno-15-28" href="#__codelineno-15-28"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-15-29" name="__codelineno-15-29" href="#__codelineno-15-29"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-15-30" name="__codelineno-15-30" href="#__codelineno-15-30"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-31" name="__codelineno-15-31" href="#__codelineno-15-31"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-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">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-15-33" name="__codelineno-15-33" href="#__codelineno-15-33"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-34" name="__codelineno-15-34" href="#__codelineno-15-34"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-15-35" name="__codelineno-15-35" href="#__codelineno-15-35"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-15-36" name="__codelineno-15-36" href="#__codelineno-15-36"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">;</span>
<a id="__codelineno-15-37" name="__codelineno-15-37" href="#__codelineno-15-37"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-15-38" name="__codelineno-15-38" href="#__codelineno-15-38"></a><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">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</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="p">}</span>
<a id="__codelineno-15-41" name="__codelineno-15-41" href="#__codelineno-15-41"></a>
<a id="__codelineno-15-42" name="__codelineno-15-42" href="#__codelineno-15-42"></a><span class="w"> </span><span class="cm">/* 队首入队操作 */</span>
<a id="__codelineno-15-43" name="__codelineno-15-43" href="#__codelineno-15-43"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">val</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-44" name="__codelineno-15-44" href="#__codelineno-15-44"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">node</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nx">ListNode</span><span class="p">(</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-15-45" name="__codelineno-15-45" href="#__codelineno-15-45"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-15-46" name="__codelineno-15-46" href="#__codelineno-15-46"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-47" name="__codelineno-15-47" href="#__codelineno-15-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-15-48" name="__codelineno-15-48" href="#__codelineno-15-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-15-49" name="__codelineno-15-49" href="#__codelineno-15-49"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-50" name="__codelineno-15-50" href="#__codelineno-15-50"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-15-51" name="__codelineno-15-51" href="#__codelineno-15-51"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span>
<a id="__codelineno-15-52" name="__codelineno-15-52" href="#__codelineno-15-52"></a><span class="w"> </span><span class="nx">node</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-15-53" name="__codelineno-15-53" href="#__codelineno-15-53"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-15-54" name="__codelineno-15-54" href="#__codelineno-15-54"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-55" name="__codelineno-15-55" href="#__codelineno-15-55"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-15-56" name="__codelineno-15-56" href="#__codelineno-15-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-57" name="__codelineno-15-57" href="#__codelineno-15-57"></a>
<a id="__codelineno-15-58" name="__codelineno-15-58" href="#__codelineno-15-58"></a><span class="w"> </span><span class="cm">/* 队尾出队操作 */</span>
<a id="__codelineno-15-59" name="__codelineno-15-59" href="#__codelineno-15-59"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-60" name="__codelineno-15-60" href="#__codelineno-15-60"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-61" name="__codelineno-15-61" href="#__codelineno-15-61"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-62" name="__codelineno-15-62" href="#__codelineno-15-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-63" name="__codelineno-15-63" href="#__codelineno-15-63"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-15-64" name="__codelineno-15-64" href="#__codelineno-15-64"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-15-65" name="__codelineno-15-65" href="#__codelineno-15-65"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="p">;</span>
<a id="__codelineno-15-66" name="__codelineno-15-66" href="#__codelineno-15-66"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-67" name="__codelineno-15-67" href="#__codelineno-15-67"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-68" name="__codelineno-15-68" href="#__codelineno-15-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-69" name="__codelineno-15-69" href="#__codelineno-15-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-70" name="__codelineno-15-70" href="#__codelineno-15-70"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-15-71" name="__codelineno-15-71" href="#__codelineno-15-71"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-15-72" name="__codelineno-15-72" href="#__codelineno-15-72"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-15-73" name="__codelineno-15-73" href="#__codelineno-15-73"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-74" name="__codelineno-15-74" href="#__codelineno-15-74"></a>
<a id="__codelineno-15-75" name="__codelineno-15-75" href="#__codelineno-15-75"></a><span class="w"> </span><span class="cm">/* 队首出队操作 */</span>
<a id="__codelineno-15-76" name="__codelineno-15-76" href="#__codelineno-15-76"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-77" name="__codelineno-15-77" href="#__codelineno-15-77"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-78" name="__codelineno-15-78" href="#__codelineno-15-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-79" name="__codelineno-15-79" href="#__codelineno-15-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-80" name="__codelineno-15-80" href="#__codelineno-15-80"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">value</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 存储尾节点值</span>
<a id="__codelineno-15-81" name="__codelineno-15-81" href="#__codelineno-15-81"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-15-82" name="__codelineno-15-82" href="#__codelineno-15-82"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-15-83" name="__codelineno-15-83" href="#__codelineno-15-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-84" name="__codelineno-15-84" href="#__codelineno-15-84"></a><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-85" name="__codelineno-15-85" href="#__codelineno-15-85"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">.</span><span class="nx">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-15-86" name="__codelineno-15-86" href="#__codelineno-15-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-87" name="__codelineno-15-87" href="#__codelineno-15-87"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-15-88" name="__codelineno-15-88" href="#__codelineno-15-88"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-15-89" name="__codelineno-15-89" href="#__codelineno-15-89"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">value</span><span class="p">;</span>
<a id="__codelineno-15-90" name="__codelineno-15-90" href="#__codelineno-15-90"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-91" name="__codelineno-15-91" href="#__codelineno-15-91"></a>
<a id="__codelineno-15-92" name="__codelineno-15-92" href="#__codelineno-15-92"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-15-93" name="__codelineno-15-93" href="#__codelineno-15-93"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-94" name="__codelineno-15-94" href="#__codelineno-15-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="kt">this.rear.val</span><span class="p">;</span>
<a id="__codelineno-15-95" name="__codelineno-15-95" href="#__codelineno-15-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-96" name="__codelineno-15-96" href="#__codelineno-15-96"></a>
<a id="__codelineno-15-97" name="__codelineno-15-97" href="#__codelineno-15-97"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-15-98" name="__codelineno-15-98" href="#__codelineno-15-98"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-99" name="__codelineno-15-99" href="#__codelineno-15-99"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="nx">null</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="kt">this.front.val</span><span class="p">;</span>
<a id="__codelineno-15-100" name="__codelineno-15-100" href="#__codelineno-15-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-101" name="__codelineno-15-101" href="#__codelineno-15-101"></a>
<a id="__codelineno-15-102" name="__codelineno-15-102" href="#__codelineno-15-102"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-15-103" name="__codelineno-15-103" href="#__codelineno-15-103"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-104" name="__codelineno-15-104" href="#__codelineno-15-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-15-105" name="__codelineno-15-105" href="#__codelineno-15-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-106" name="__codelineno-15-106" href="#__codelineno-15-106"></a>
<a id="__codelineno-15-107" name="__codelineno-15-107" href="#__codelineno-15-107"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-15-108" name="__codelineno-15-108" href="#__codelineno-15-108"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-109" name="__codelineno-15-109" href="#__codelineno-15-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-15-110" name="__codelineno-15-110" href="#__codelineno-15-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-111" name="__codelineno-15-111" href="#__codelineno-15-111"></a>
<a id="__codelineno-15-112" name="__codelineno-15-112" href="#__codelineno-15-112"></a><span class="w"> </span><span class="cm">/* 打印双向队列 */</span>
<a id="__codelineno-15-113" name="__codelineno-15-113" href="#__codelineno-15-113"></a><span class="w"> </span><span class="nx">print</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-114" name="__codelineno-15-114" href="#__codelineno-15-114"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">arr</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-15-115" name="__codelineno-15-115" href="#__codelineno-15-115"></a><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nx">temp</span><span class="o">:</span><span class="w"> </span><span class="kt">ListNode</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span>
<a id="__codelineno-15-116" name="__codelineno-15-116" href="#__codelineno-15-116"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="nx">temp</span><span class="w"> </span><span class="o">!==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-15-117" name="__codelineno-15-117" href="#__codelineno-15-117"></a><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">temp</span><span class="p">.</span><span class="nx">val</span><span class="p">);</span>
<a id="__codelineno-15-118" name="__codelineno-15-118" href="#__codelineno-15-118"></a><span class="w"> </span><span class="nx">temp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">temp</span><span class="p">.</span><span class="nx">next</span><span class="p">;</span>
<a id="__codelineno-15-119" name="__codelineno-15-119" href="#__codelineno-15-119"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-120" name="__codelineno-15-120" href="#__codelineno-15-120"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;[&#39;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">arr</span><span class="p">.</span><span class="nx">join</span><span class="p">(</span><span class="s1">&#39;, &#39;</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s1">&#39;]&#39;</span><span class="p">);</span>
<a id="__codelineno-15-121" name="__codelineno-15-121" href="#__codelineno-15-121"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-15-122" name="__codelineno-15-122" href="#__codelineno-15-122"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.c</span><pre><span></span><code><a id="__codelineno-16-1" name="__codelineno-16-1" href="#__codelineno-16-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-16-2" name="__codelineno-16-2" href="#__codelineno-16-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-3" name="__codelineno-16-3" href="#__codelineno-16-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-16-4" name="__codelineno-16-4" href="#__codelineno-16-4"></a><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点</span>
<a id="__codelineno-16-5" name="__codelineno-16-5" href="#__codelineno-16-5"></a><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点</span>
<a id="__codelineno-16-6" name="__codelineno-16-6" href="#__codelineno-16-6"></a><span class="p">};</span>
<a id="__codelineno-16-7" name="__codelineno-16-7" href="#__codelineno-16-7"></a>
<a id="__codelineno-16-8" name="__codelineno-16-8" href="#__codelineno-16-8"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">doublyListNode</span><span class="w"> </span><span class="n">doublyListNode</span><span class="p">;</span>
<a id="__codelineno-16-9" name="__codelineno-16-9" href="#__codelineno-16-9"></a>
<a id="__codelineno-16-10" name="__codelineno-16-10" href="#__codelineno-16-10"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-16-11" name="__codelineno-16-11" href="#__codelineno-16-11"></a><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="nf">newDoublyListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-12" name="__codelineno-16-12" href="#__codelineno-16-12"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">new</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">doublyListNode</span><span class="p">));</span>
<a id="__codelineno-16-13" name="__codelineno-16-13" href="#__codelineno-16-13"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-16-14" name="__codelineno-16-14" href="#__codelineno-16-14"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-15" name="__codelineno-16-15" href="#__codelineno-16-15"></a><span class="w"> </span><span class="n">new</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-16" name="__codelineno-16-16" href="#__codelineno-16-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">new</span><span class="p">;</span>
<a id="__codelineno-16-17" name="__codelineno-16-17" href="#__codelineno-16-17"></a><span class="p">}</span>
<a id="__codelineno-16-18" name="__codelineno-16-18" href="#__codelineno-16-18"></a>
<a id="__codelineno-16-19" name="__codelineno-16-19" href="#__codelineno-16-19"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-16-20" name="__codelineno-16-20" href="#__codelineno-16-20"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delDoublyListNode</span><span class="p">(</span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-21" name="__codelineno-16-21" href="#__codelineno-16-21"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">node</span><span class="p">);</span>
<a id="__codelineno-16-22" name="__codelineno-16-22" href="#__codelineno-16-22"></a><span class="p">}</span>
<a id="__codelineno-16-23" name="__codelineno-16-23" href="#__codelineno-16-23"></a>
<a id="__codelineno-16-24" name="__codelineno-16-24" href="#__codelineno-16-24"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-16-25" name="__codelineno-16-25" href="#__codelineno-16-25"></a><span class="k">struct</span><span class="w"> </span><span class="nc">linkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-26" name="__codelineno-16-26" href="#__codelineno-16-26"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="o">*</span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front ，尾节点 rear</span>
<a id="__codelineno-16-27" name="__codelineno-16-27" href="#__codelineno-16-27"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-16-28" name="__codelineno-16-28" href="#__codelineno-16-28"></a><span class="p">};</span>
<a id="__codelineno-16-29" name="__codelineno-16-29" href="#__codelineno-16-29"></a>
<a id="__codelineno-16-30" name="__codelineno-16-30" href="#__codelineno-16-30"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">linkedListDeque</span><span class="w"> </span><span class="n">linkedListDeque</span><span class="p">;</span>
<a id="__codelineno-16-31" name="__codelineno-16-31" href="#__codelineno-16-31"></a>
<a id="__codelineno-16-32" name="__codelineno-16-32" href="#__codelineno-16-32"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-16-33" name="__codelineno-16-33" href="#__codelineno-16-33"></a><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="nf">newLinkedListDeque</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-34" name="__codelineno-16-34" href="#__codelineno-16-34"></a><span class="w"> </span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="p">));</span>
<a id="__codelineno-16-35" name="__codelineno-16-35" href="#__codelineno-16-35"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-36" name="__codelineno-16-36" href="#__codelineno-16-36"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-37" name="__codelineno-16-37" href="#__codelineno-16-37"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-16-38" name="__codelineno-16-38" href="#__codelineno-16-38"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-16-39" name="__codelineno-16-39" href="#__codelineno-16-39"></a><span class="p">}</span>
<a id="__codelineno-16-40" name="__codelineno-16-40" href="#__codelineno-16-40"></a>
<a id="__codelineno-16-41" name="__codelineno-16-41" href="#__codelineno-16-41"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-16-42" name="__codelineno-16-42" href="#__codelineno-16-42"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delLinkedListdeque</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-43" name="__codelineno-16-43" href="#__codelineno-16-43"></a><span class="w"> </span><span class="c1">// 释放所有节点</span>
<a id="__codelineno-16-44" name="__codelineno-16-44" href="#__codelineno-16-44"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-45" name="__codelineno-16-45" href="#__codelineno-16-45"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">tmp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-16-46" name="__codelineno-16-46" href="#__codelineno-16-46"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-16-47" name="__codelineno-16-47" href="#__codelineno-16-47"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">tmp</span><span class="p">);</span>
<a id="__codelineno-16-48" name="__codelineno-16-48" href="#__codelineno-16-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-49" name="__codelineno-16-49" href="#__codelineno-16-49"></a><span class="w"> </span><span class="c1">// 释放 deque 结构体</span>
<a id="__codelineno-16-50" name="__codelineno-16-50" href="#__codelineno-16-50"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-16-51" name="__codelineno-16-51" href="#__codelineno-16-51"></a><span class="p">}</span>
<a id="__codelineno-16-52" name="__codelineno-16-52" href="#__codelineno-16-52"></a>
<a id="__codelineno-16-53" name="__codelineno-16-53" href="#__codelineno-16-53"></a><span class="cm">/* 获取队列的长度 */</span>
<a id="__codelineno-16-54" name="__codelineno-16-54" href="#__codelineno-16-54"></a><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-55" name="__codelineno-16-55" href="#__codelineno-16-55"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-16-56" name="__codelineno-16-56" href="#__codelineno-16-56"></a><span class="p">}</span>
<a id="__codelineno-16-57" name="__codelineno-16-57" href="#__codelineno-16-57"></a>
<a id="__codelineno-16-58" name="__codelineno-16-58" href="#__codelineno-16-58"></a><span class="cm">/* 判断队列是否为空 */</span>
<a id="__codelineno-16-59" name="__codelineno-16-59" href="#__codelineno-16-59"></a><span class="kt">bool</span><span class="w"> </span><span class="nf">empty</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-60" name="__codelineno-16-60" href="#__codelineno-16-60"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-16-61" name="__codelineno-16-61" href="#__codelineno-16-61"></a><span class="p">}</span>
<a id="__codelineno-16-62" name="__codelineno-16-62" href="#__codelineno-16-62"></a>
<a id="__codelineno-16-63" name="__codelineno-16-63" href="#__codelineno-16-63"></a><span class="cm">/* 入队 */</span>
<a id="__codelineno-16-64" name="__codelineno-16-64" href="#__codelineno-16-64"></a><span class="kt">void</span><span class="w"> </span><span class="nf">push</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-65" name="__codelineno-16-65" href="#__codelineno-16-65"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">newDoublyListNode</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-16-66" name="__codelineno-16-66" href="#__codelineno-16-66"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向node</span>
<a id="__codelineno-16-67" name="__codelineno-16-67" href="#__codelineno-16-67"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-68" name="__codelineno-16-68" href="#__codelineno-16-68"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-16-69" name="__codelineno-16-69" href="#__codelineno-16-69"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-70" name="__codelineno-16-70" href="#__codelineno-16-70"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-16-71" name="__codelineno-16-71" href="#__codelineno-16-71"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-72" name="__codelineno-16-72" href="#__codelineno-16-72"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-16-73" name="__codelineno-16-73" href="#__codelineno-16-73"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-16-74" name="__codelineno-16-74" href="#__codelineno-16-74"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-16-75" name="__codelineno-16-75" href="#__codelineno-16-75"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-16-76" name="__codelineno-16-76" href="#__codelineno-16-76"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-77" name="__codelineno-16-77" href="#__codelineno-16-77"></a><span class="w"> </span><span class="c1">// 对尾入队操作</span>
<a id="__codelineno-16-78" name="__codelineno-16-78" href="#__codelineno-16-78"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-79" name="__codelineno-16-79" href="#__codelineno-16-79"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-16-80" name="__codelineno-16-80" href="#__codelineno-16-80"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-16-81" name="__codelineno-16-81" href="#__codelineno-16-81"></a><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-16-82" name="__codelineno-16-82" href="#__codelineno-16-82"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-16-83" name="__codelineno-16-83" href="#__codelineno-16-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-84" name="__codelineno-16-84" href="#__codelineno-16-84"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-16-85" name="__codelineno-16-85" href="#__codelineno-16-85"></a><span class="p">}</span>
<a id="__codelineno-16-86" name="__codelineno-16-86" href="#__codelineno-16-86"></a>
<a id="__codelineno-16-87" name="__codelineno-16-87" href="#__codelineno-16-87"></a><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-16-88" name="__codelineno-16-88" href="#__codelineno-16-88"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-89" name="__codelineno-16-89" href="#__codelineno-16-89"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-16-90" name="__codelineno-16-90" href="#__codelineno-16-90"></a><span class="p">}</span>
<a id="__codelineno-16-91" name="__codelineno-16-91" href="#__codelineno-16-91"></a>
<a id="__codelineno-16-92" name="__codelineno-16-92" href="#__codelineno-16-92"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-16-93" name="__codelineno-16-93" href="#__codelineno-16-93"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-94" name="__codelineno-16-94" href="#__codelineno-16-94"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-16-95" name="__codelineno-16-95" href="#__codelineno-16-95"></a><span class="p">}</span>
<a id="__codelineno-16-96" name="__codelineno-16-96" href="#__codelineno-16-96"></a>
<a id="__codelineno-16-97" name="__codelineno-16-97" href="#__codelineno-16-97"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-16-98" name="__codelineno-16-98" href="#__codelineno-16-98"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-99" name="__codelineno-16-99" href="#__codelineno-16-99"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">);</span>
<a id="__codelineno-16-100" name="__codelineno-16-100" href="#__codelineno-16-100"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-16-101" name="__codelineno-16-101" href="#__codelineno-16-101"></a><span class="p">}</span>
<a id="__codelineno-16-102" name="__codelineno-16-102" href="#__codelineno-16-102"></a>
<a id="__codelineno-16-103" name="__codelineno-16-103" href="#__codelineno-16-103"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-16-104" name="__codelineno-16-104" href="#__codelineno-16-104"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-105" name="__codelineno-16-105" href="#__codelineno-16-105"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">size</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">&amp;&amp;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">);</span>
<a id="__codelineno-16-106" name="__codelineno-16-106" href="#__codelineno-16-106"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-16-107" name="__codelineno-16-107" href="#__codelineno-16-107"></a><span class="p">}</span>
<a id="__codelineno-16-108" name="__codelineno-16-108" href="#__codelineno-16-108"></a>
<a id="__codelineno-16-109" name="__codelineno-16-109" href="#__codelineno-16-109"></a><span class="cm">/* 出队 */</span>
<a id="__codelineno-16-110" name="__codelineno-16-110" href="#__codelineno-16-110"></a><span class="kt">int</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-111" name="__codelineno-16-111" href="#__codelineno-16-111"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span>
<a id="__codelineno-16-112" name="__codelineno-16-112" href="#__codelineno-16-112"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<a id="__codelineno-16-113" name="__codelineno-16-113" href="#__codelineno-16-113"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-16-114" name="__codelineno-16-114" href="#__codelineno-16-114"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-16-115" name="__codelineno-16-115" href="#__codelineno-16-115"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-116" name="__codelineno-16-116" href="#__codelineno-16-116"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-16-117" name="__codelineno-16-117" href="#__codelineno-16-117"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-16-118" name="__codelineno-16-118" href="#__codelineno-16-118"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-119" name="__codelineno-16-119" href="#__codelineno-16-119"></a><span class="w"> </span><span class="n">fNext</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-120" name="__codelineno-16-120" href="#__codelineno-16-120"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-121" name="__codelineno-16-121" href="#__codelineno-16-121"></a><span class="w"> </span><span class="n">delDoublyListNode</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">);</span>
<a id="__codelineno-16-122" name="__codelineno-16-122" href="#__codelineno-16-122"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-123" name="__codelineno-16-123" href="#__codelineno-16-123"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-16-124" name="__codelineno-16-124" href="#__codelineno-16-124"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-125" name="__codelineno-16-125" href="#__codelineno-16-125"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-16-126" name="__codelineno-16-126" href="#__codelineno-16-126"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-127" name="__codelineno-16-127" href="#__codelineno-16-127"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-16-128" name="__codelineno-16-128" href="#__codelineno-16-128"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-16-129" name="__codelineno-16-129" href="#__codelineno-16-129"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-130" name="__codelineno-16-130" href="#__codelineno-16-130"></a><span class="w"> </span><span class="n">rPrev</span><span class="o">-&gt;</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-131" name="__codelineno-16-131" href="#__codelineno-16-131"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="o">-&gt;</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<a id="__codelineno-16-132" name="__codelineno-16-132" href="#__codelineno-16-132"></a><span class="w"> </span><span class="n">delDoublyListNode</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="p">);</span>
<a id="__codelineno-16-133" name="__codelineno-16-133" href="#__codelineno-16-133"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-134" name="__codelineno-16-134" href="#__codelineno-16-134"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-16-135" name="__codelineno-16-135" href="#__codelineno-16-135"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-136" name="__codelineno-16-136" href="#__codelineno-16-136"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-16-137" name="__codelineno-16-137" href="#__codelineno-16-137"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-16-138" name="__codelineno-16-138" href="#__codelineno-16-138"></a><span class="p">}</span>
<a id="__codelineno-16-139" name="__codelineno-16-139" href="#__codelineno-16-139"></a>
<a id="__codelineno-16-140" name="__codelineno-16-140" href="#__codelineno-16-140"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-16-141" name="__codelineno-16-141" href="#__codelineno-16-141"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-142" name="__codelineno-16-142" href="#__codelineno-16-142"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="nb">true</span><span class="p">);</span>
<a id="__codelineno-16-143" name="__codelineno-16-143" href="#__codelineno-16-143"></a><span class="p">}</span>
<a id="__codelineno-16-144" name="__codelineno-16-144" href="#__codelineno-16-144"></a>
<a id="__codelineno-16-145" name="__codelineno-16-145" href="#__codelineno-16-145"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-16-146" name="__codelineno-16-146" href="#__codelineno-16-146"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-147" name="__codelineno-16-147" href="#__codelineno-16-147"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="nb">false</span><span class="p">);</span>
<a id="__codelineno-16-148" name="__codelineno-16-148" href="#__codelineno-16-148"></a><span class="p">}</span>
<a id="__codelineno-16-149" name="__codelineno-16-149" href="#__codelineno-16-149"></a>
<a id="__codelineno-16-150" name="__codelineno-16-150" href="#__codelineno-16-150"></a><span class="cm">/* 打印队列 */</span>
<a id="__codelineno-16-151" name="__codelineno-16-151" href="#__codelineno-16-151"></a><span class="kt">void</span><span class="w"> </span><span class="nf">printLinkedListDeque</span><span class="p">(</span><span class="n">linkedListDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-152" name="__codelineno-16-152" href="#__codelineno-16-152"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-16-153" name="__codelineno-16-153" href="#__codelineno-16-153"></a><span class="w"> </span><span class="c1">// 拷贝链表中的数据到数组</span>
<a id="__codelineno-16-154" name="__codelineno-16-154" href="#__codelineno-16-154"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<a id="__codelineno-16-155" name="__codelineno-16-155" href="#__codelineno-16-155"></a><span class="w"> </span><span class="n">doublyListNode</span><span class="w"> </span><span class="o">*</span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-16-156" name="__codelineno-16-156" href="#__codelineno-16-156"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-16-157" name="__codelineno-16-157" href="#__codelineno-16-157"></a><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-16-158" name="__codelineno-16-158" href="#__codelineno-16-158"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="o">-&gt;</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-16-159" name="__codelineno-16-159" href="#__codelineno-16-159"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-16-160" name="__codelineno-16-160" href="#__codelineno-16-160"></a><span class="w"> </span><span class="n">printArray</span><span class="p">(</span><span class="n">arr</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-16-161" name="__codelineno-16-161" href="#__codelineno-16-161"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.cs</span><pre><span></span><code><a id="__codelineno-17-1" name="__codelineno-17-1" href="#__codelineno-17-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-17-2" name="__codelineno-17-2" href="#__codelineno-17-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ListNode</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-3" name="__codelineno-17-3" href="#__codelineno-17-3"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-17-4" name="__codelineno-17-4" href="#__codelineno-17-4"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">next</span><span class="p">;</span><span class="w"> </span><span class="c1">// 后继节点引用（指针）</span>
<a id="__codelineno-17-5" name="__codelineno-17-5" href="#__codelineno-17-5"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">prev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 前驱节点引用（指针）</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">ListNode</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-8" name="__codelineno-17-8" href="#__codelineno-17-8"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-17-9" name="__codelineno-17-9" href="#__codelineno-17-9"></a><span class="w"> </span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-10" name="__codelineno-17-10" href="#__codelineno-17-10"></a><span class="w"> </span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-11" name="__codelineno-17-11" href="#__codelineno-17-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-12" name="__codelineno-17-12" href="#__codelineno-17-12"></a><span class="p">}</span>
<a id="__codelineno-17-13" name="__codelineno-17-13" href="#__codelineno-17-13"></a>
<a id="__codelineno-17-14" name="__codelineno-17-14" href="#__codelineno-17-14"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-17-15" name="__codelineno-17-15" href="#__codelineno-17-15"></a><span class="k">class</span><span class="w"> </span><span class="nc">LinkedListDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-16" name="__codelineno-17-16" href="#__codelineno-17-16"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="n">ListNode</span><span class="o">?</span><span class="w"> </span><span class="n">front</span><span class="p">,</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span><span class="w"> </span><span class="c1">// 头节点 front, 尾节点 rear</span>
<a id="__codelineno-17-17" name="__codelineno-17-17" href="#__codelineno-17-17"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-17-18" name="__codelineno-17-18" href="#__codelineno-17-18"></a>
<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="nf">LinkedListDeque</span><span class="p">()</span><span class="w"> </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="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-21" name="__codelineno-17-21" href="#__codelineno-17-21"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-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">/* 获取双向队列的长度 */</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="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-17-26" name="__codelineno-17-26" href="#__codelineno-17-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-17-27" name="__codelineno-17-27" href="#__codelineno-17-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-28" name="__codelineno-17-28" href="#__codelineno-17-28"></a>
<a id="__codelineno-17-29" name="__codelineno-17-29" href="#__codelineno-17-29"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-17-30" name="__codelineno-17-30" href="#__codelineno-17-30"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-31" name="__codelineno-17-31" href="#__codelineno-17-31"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-17-32" name="__codelineno-17-32" href="#__codelineno-17-32"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-33" name="__codelineno-17-33" href="#__codelineno-17-33"></a>
<a id="__codelineno-17-34" name="__codelineno-17-34" href="#__codelineno-17-34"></a><span class="w"> </span><span class="cm">/* 入队操作 */</span>
<a id="__codelineno-17-35" name="__codelineno-17-35" href="#__codelineno-17-35"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">push</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-36" name="__codelineno-17-36" href="#__codelineno-17-36"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">ListNode</span><span class="p">(</span><span class="n">num</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="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-17-38" name="__codelineno-17-38" href="#__codelineno-17-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-39" name="__codelineno-17-39" href="#__codelineno-17-39"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-17-40" name="__codelineno-17-40" href="#__codelineno-17-40"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-17-41" name="__codelineno-17-41" href="#__codelineno-17-41"></a><span class="w"> </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="c1">// 队首入队操作</span>
<a id="__codelineno-17-43" name="__codelineno-17-43" href="#__codelineno-17-43"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="nf">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-44" name="__codelineno-17-44" href="#__codelineno-17-44"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-17-45" name="__codelineno-17-45" href="#__codelineno-17-45"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-17-46" name="__codelineno-17-46" href="#__codelineno-17-46"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-17-47" name="__codelineno-17-47" href="#__codelineno-17-47"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点 </span>
<a id="__codelineno-17-48" name="__codelineno-17-48" href="#__codelineno-17-48"></a><span class="w"> </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="c1">// 队尾入队操作</span>
<a id="__codelineno-17-50" name="__codelineno-17-50" href="#__codelineno-17-50"></a><span class="w"> </span><span class="k">else</span><span class="w"> </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="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-17-52" name="__codelineno-17-52" href="#__codelineno-17-52"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-17-53" name="__codelineno-17-53" href="#__codelineno-17-53"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-17-54" name="__codelineno-17-54" href="#__codelineno-17-54"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-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>
<a id="__codelineno-17-57" name="__codelineno-17-57" href="#__codelineno-17-57"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-17-58" name="__codelineno-17-58" href="#__codelineno-17-58"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-59" name="__codelineno-17-59" href="#__codelineno-17-59"></a>
<a id="__codelineno-17-60" name="__codelineno-17-60" href="#__codelineno-17-60"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-17-61" name="__codelineno-17-61" href="#__codelineno-17-61"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-62" name="__codelineno-17-62" href="#__codelineno-17-62"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="k">true</span><span class="p">);</span>
<a id="__codelineno-17-63" name="__codelineno-17-63" href="#__codelineno-17-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-64" name="__codelineno-17-64" href="#__codelineno-17-64"></a>
<a id="__codelineno-17-65" name="__codelineno-17-65" href="#__codelineno-17-65"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-17-66" name="__codelineno-17-66" href="#__codelineno-17-66"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-67" name="__codelineno-17-67" href="#__codelineno-17-67"></a><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="k">false</span><span class="p">);</span>
<a id="__codelineno-17-68" name="__codelineno-17-68" href="#__codelineno-17-68"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-69" name="__codelineno-17-69" href="#__codelineno-17-69"></a>
<a id="__codelineno-17-70" name="__codelineno-17-70" href="#__codelineno-17-70"></a><span class="w"> </span><span class="cm">/* 出队操作 */</span>
<a id="__codelineno-17-71" name="__codelineno-17-71" href="#__codelineno-17-71"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="kt">bool</span><span class="w"> </span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-72" name="__codelineno-17-72" href="#__codelineno-17-72"></a><span class="w"> </span><span class="c1">// 若队列为空，直接返回 null</span>
<a id="__codelineno-17-73" name="__codelineno-17-73" href="#__codelineno-17-73"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-74" name="__codelineno-17-74" href="#__codelineno-17-74"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-75" name="__codelineno-17-75" href="#__codelineno-17-75"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-76" name="__codelineno-17-76" href="#__codelineno-17-76"></a>
<a id="__codelineno-17-77" name="__codelineno-17-77" href="#__codelineno-17-77"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-17-78" name="__codelineno-17-78" href="#__codelineno-17-78"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-17-79" name="__codelineno-17-79" href="#__codelineno-17-79"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isFront</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-80" name="__codelineno-17-80" href="#__codelineno-17-80"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-17-81" name="__codelineno-17-81" href="#__codelineno-17-81"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-17-82" name="__codelineno-17-82" href="#__codelineno-17-82"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-17-83" name="__codelineno-17-83" href="#__codelineno-17-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-84" name="__codelineno-17-84" href="#__codelineno-17-84"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-85" name="__codelineno-17-85" href="#__codelineno-17-85"></a><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-86" name="__codelineno-17-86" href="#__codelineno-17-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-87" name="__codelineno-17-87" href="#__codelineno-17-87"></a>
<a id="__codelineno-17-88" name="__codelineno-17-88" href="#__codelineno-17-88"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-17-89" name="__codelineno-17-89" href="#__codelineno-17-89"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-90" name="__codelineno-17-90" href="#__codelineno-17-90"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-17-91" name="__codelineno-17-91" href="#__codelineno-17-91"></a><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-92" name="__codelineno-17-92" href="#__codelineno-17-92"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-17-93" name="__codelineno-17-93" href="#__codelineno-17-93"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-17-94" name="__codelineno-17-94" href="#__codelineno-17-94"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-17-95" name="__codelineno-17-95" href="#__codelineno-17-95"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="k">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-96" name="__codelineno-17-96" href="#__codelineno-17-96"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-97" name="__codelineno-17-97" href="#__codelineno-17-97"></a><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">null</span><span class="p">;</span>
<a id="__codelineno-17-98" name="__codelineno-17-98" href="#__codelineno-17-98"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-99" name="__codelineno-17-99" href="#__codelineno-17-99"></a>
<a id="__codelineno-17-100" name="__codelineno-17-100" href="#__codelineno-17-100"></a><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-17-101" name="__codelineno-17-101" href="#__codelineno-17-101"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-102" name="__codelineno-17-102" href="#__codelineno-17-102"></a>
<a id="__codelineno-17-103" name="__codelineno-17-103" href="#__codelineno-17-103"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-17-104" name="__codelineno-17-104" href="#__codelineno-17-104"></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-17-105" name="__codelineno-17-105" href="#__codelineno-17-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-106" name="__codelineno-17-106" href="#__codelineno-17-106"></a>
<a id="__codelineno-17-107" name="__codelineno-17-107" href="#__codelineno-17-107"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-17-108" name="__codelineno-17-108" href="#__codelineno-17-108"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-109" name="__codelineno-17-109" href="#__codelineno-17-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="k">true</span><span class="p">);</span>
<a id="__codelineno-17-110" name="__codelineno-17-110" href="#__codelineno-17-110"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-111" name="__codelineno-17-111" href="#__codelineno-17-111"></a>
<a id="__codelineno-17-112" name="__codelineno-17-112" href="#__codelineno-17-112"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-17-113" name="__codelineno-17-113" href="#__codelineno-17-113"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-114" name="__codelineno-17-114" href="#__codelineno-17-114"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">pop</span><span class="p">(</span><span class="k">false</span><span class="p">);</span>
<a id="__codelineno-17-115" name="__codelineno-17-115" href="#__codelineno-17-115"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-116" name="__codelineno-17-116" href="#__codelineno-17-116"></a>
<a id="__codelineno-17-117" name="__codelineno-17-117" href="#__codelineno-17-117"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-17-118" name="__codelineno-17-118" href="#__codelineno-17-118"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-119" name="__codelineno-17-119" href="#__codelineno-17-119"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="k">null</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">front</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-17-120" name="__codelineno-17-120" href="#__codelineno-17-120"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-121" name="__codelineno-17-121" href="#__codelineno-17-121"></a>
<a id="__codelineno-17-122" name="__codelineno-17-122" href="#__codelineno-17-122"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-17-123" name="__codelineno-17-123" href="#__codelineno-17-123"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int?</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-124" name="__codelineno-17-124" href="#__codelineno-17-124"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="o">?</span><span class="w"> </span><span class="k">null</span><span class="w"> </span><span class="p">:</span><span class="w"> </span><span class="n">rear</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-17-125" name="__codelineno-17-125" href="#__codelineno-17-125"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-126" name="__codelineno-17-126" href="#__codelineno-17-126"></a>
<a id="__codelineno-17-127" name="__codelineno-17-127" href="#__codelineno-17-127"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-17-128" name="__codelineno-17-128" href="#__codelineno-17-128"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="nf">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-129" name="__codelineno-17-129" href="#__codelineno-17-129"></a><span class="w"> </span><span class="n">ListNode</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-17-130" name="__codelineno-17-130" href="#__codelineno-17-130"></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-17-131" name="__codelineno-17-131" href="#__codelineno-17-131"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">Length</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-17-132" name="__codelineno-17-132" href="#__codelineno-17-132"></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-17-133" name="__codelineno-17-133" href="#__codelineno-17-133"></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-17-134" name="__codelineno-17-134" href="#__codelineno-17-134"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-135" name="__codelineno-17-135" href="#__codelineno-17-135"></a>
<a id="__codelineno-17-136" name="__codelineno-17-136" href="#__codelineno-17-136"></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-17-137" name="__codelineno-17-137" href="#__codelineno-17-137"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-17-138" name="__codelineno-17-138" href="#__codelineno-17-138"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.swift</span><pre><span></span><code><a id="__codelineno-18-1" name="__codelineno-18-1" href="#__codelineno-18-1"></a><span class="cm">/* 双向链表节点 */</span>
<a id="__codelineno-18-2" name="__codelineno-18-2" href="#__codelineno-18-2"></a><span class="kd">class</span> <span class="nc">ListNode</span> <span class="p">{</span>
<a id="__codelineno-18-3" name="__codelineno-18-3" href="#__codelineno-18-3"></a> <span class="kd">var</span> <span class="nv">val</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 节点值</span>
<a id="__codelineno-18-4" name="__codelineno-18-4" href="#__codelineno-18-4"></a> <span class="kd">var</span> <span class="nv">next</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 后继节点引用（指针）</span>
<a id="__codelineno-18-5" name="__codelineno-18-5" href="#__codelineno-18-5"></a> <span class="kd">var</span> <span class="nv">prev</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 前驱节点引用（指针）</span>
<a id="__codelineno-18-6" name="__codelineno-18-6" href="#__codelineno-18-6"></a>
<a id="__codelineno-18-7" name="__codelineno-18-7" href="#__codelineno-18-7"></a> <span class="kd">init</span><span class="p">(</span><span class="n">val</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-18-8" name="__codelineno-18-8" href="#__codelineno-18-8"></a> <span class="kc">self</span><span class="p">.</span><span class="n">val</span> <span class="p">=</span> <span class="n">val</span>
<a id="__codelineno-18-9" name="__codelineno-18-9" href="#__codelineno-18-9"></a> <span class="p">}</span>
<a id="__codelineno-18-10" name="__codelineno-18-10" href="#__codelineno-18-10"></a><span class="p">}</span>
<a id="__codelineno-18-11" name="__codelineno-18-11" href="#__codelineno-18-11"></a>
<a id="__codelineno-18-12" name="__codelineno-18-12" href="#__codelineno-18-12"></a><span class="cm">/* 基于双向链表实现的双向队列 */</span>
<a id="__codelineno-18-13" name="__codelineno-18-13" href="#__codelineno-18-13"></a><span class="kd">class</span> <span class="nc">LinkedListDeque</span> <span class="p">{</span>
<a id="__codelineno-18-14" name="__codelineno-18-14" href="#__codelineno-18-14"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">front</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 头节点 front</span>
<a id="__codelineno-18-15" name="__codelineno-18-15" href="#__codelineno-18-15"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">rear</span><span class="p">:</span> <span class="n">ListNode</span><span class="p">?</span> <span class="c1">// 尾节点 rear</span>
<a id="__codelineno-18-16" name="__codelineno-18-16" href="#__codelineno-18-16"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">queSize</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 双向队列的长度</span>
<a id="__codelineno-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="kd">init</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-18-19" name="__codelineno-18-19" href="#__codelineno-18-19"></a> <span class="n">queSize</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-18-20" name="__codelineno-18-20" href="#__codelineno-18-20"></a> <span class="p">}</span>
<a id="__codelineno-18-21" name="__codelineno-18-21" href="#__codelineno-18-21"></a>
<a id="__codelineno-18-22" name="__codelineno-18-22" href="#__codelineno-18-22"></a> <span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-18-23" name="__codelineno-18-23" href="#__codelineno-18-23"></a> <span class="kd">func</span> <span class="nf">size</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-24" name="__codelineno-18-24" href="#__codelineno-18-24"></a> <span class="n">queSize</span>
<a id="__codelineno-18-25" name="__codelineno-18-25" href="#__codelineno-18-25"></a> <span class="p">}</span>
<a id="__codelineno-18-26" name="__codelineno-18-26" href="#__codelineno-18-26"></a>
<a id="__codelineno-18-27" name="__codelineno-18-27" href="#__codelineno-18-27"></a> <span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-18-28" name="__codelineno-18-28" href="#__codelineno-18-28"></a> <span class="kd">func</span> <span class="nf">isEmpty</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Bool</span> <span class="p">{</span>
<a id="__codelineno-18-29" name="__codelineno-18-29" href="#__codelineno-18-29"></a> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="mi">0</span>
<a id="__codelineno-18-30" name="__codelineno-18-30" href="#__codelineno-18-30"></a> <span class="p">}</span>
<a id="__codelineno-18-31" name="__codelineno-18-31" href="#__codelineno-18-31"></a>
<a id="__codelineno-18-32" name="__codelineno-18-32" href="#__codelineno-18-32"></a> <span class="cm">/* 入队操作 */</span>
<a id="__codelineno-18-33" name="__codelineno-18-33" href="#__codelineno-18-33"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="nb">Bool</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-18-34" name="__codelineno-18-34" href="#__codelineno-18-34"></a> <span class="kd">let</span> <span class="nv">node</span> <span class="p">=</span> <span class="n">ListNode</span><span class="p">(</span><span class="n">val</span><span class="p">:</span> <span class="n">num</span><span class="p">)</span>
<a id="__codelineno-18-35" name="__codelineno-18-35" href="#__codelineno-18-35"></a> <span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-18-36" name="__codelineno-18-36" href="#__codelineno-18-36"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-18-37" name="__codelineno-18-37" href="#__codelineno-18-37"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-18-38" name="__codelineno-18-38" href="#__codelineno-18-38"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">node</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="c1">// 队首入队操作</span>
<a id="__codelineno-18-41" name="__codelineno-18-41" href="#__codelineno-18-41"></a> <span class="k">else</span> <span class="k">if</span> <span class="n">isFront</span> <span class="p">{</span>
<a id="__codelineno-18-42" name="__codelineno-18-42" href="#__codelineno-18-42"></a> <span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-18-43" name="__codelineno-18-43" href="#__codelineno-18-43"></a> <span class="n">front</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-18-44" name="__codelineno-18-44" href="#__codelineno-18-44"></a> <span class="n">node</span><span class="p">.</span><span class="n">next</span> <span class="p">=</span> <span class="n">front</span>
<a id="__codelineno-18-45" name="__codelineno-18-45" href="#__codelineno-18-45"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">node</span> <span class="c1">// 更新头节点</span>
<a id="__codelineno-18-46" name="__codelineno-18-46" href="#__codelineno-18-46"></a> <span class="p">}</span>
<a id="__codelineno-18-47" name="__codelineno-18-47" href="#__codelineno-18-47"></a> <span class="c1">// 队尾入队操作</span>
<a id="__codelineno-18-48" name="__codelineno-18-48" href="#__codelineno-18-48"></a> <span class="k">else</span> <span class="p">{</span>
<a id="__codelineno-18-49" name="__codelineno-18-49" href="#__codelineno-18-49"></a> <span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-18-50" name="__codelineno-18-50" href="#__codelineno-18-50"></a> <span class="n">rear</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="n">node</span>
<a id="__codelineno-18-51" name="__codelineno-18-51" href="#__codelineno-18-51"></a> <span class="n">node</span><span class="p">.</span><span class="n">prev</span> <span class="p">=</span> <span class="n">rear</span>
<a id="__codelineno-18-52" name="__codelineno-18-52" href="#__codelineno-18-52"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">node</span> <span class="c1">// 更新尾节点</span>
<a id="__codelineno-18-53" name="__codelineno-18-53" href="#__codelineno-18-53"></a> <span class="p">}</span>
<a id="__codelineno-18-54" name="__codelineno-18-54" href="#__codelineno-18-54"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span> <span class="c1">// 更新队列长度</span>
<a id="__codelineno-18-55" name="__codelineno-18-55" href="#__codelineno-18-55"></a> <span class="p">}</span>
<a id="__codelineno-18-56" name="__codelineno-18-56" href="#__codelineno-18-56"></a>
<a id="__codelineno-18-57" name="__codelineno-18-57" href="#__codelineno-18-57"></a> <span class="cm">/* 队首入队 */</span>
<a id="__codelineno-18-58" name="__codelineno-18-58" href="#__codelineno-18-58"></a> <span class="kd">func</span> <span class="nf">pushFirst</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-18-59" name="__codelineno-18-59" href="#__codelineno-18-59"></a> <span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="n">num</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="kc">true</span><span class="p">)</span>
<a id="__codelineno-18-60" name="__codelineno-18-60" href="#__codelineno-18-60"></a> <span class="p">}</span>
<a id="__codelineno-18-61" name="__codelineno-18-61" href="#__codelineno-18-61"></a>
<a id="__codelineno-18-62" name="__codelineno-18-62" href="#__codelineno-18-62"></a> <span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-18-63" name="__codelineno-18-63" href="#__codelineno-18-63"></a> <span class="kd">func</span> <span class="nf">pushLast</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-18-64" name="__codelineno-18-64" href="#__codelineno-18-64"></a> <span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="n">num</span><span class="p">,</span> <span class="n">isFront</span><span class="p">:</span> <span class="kc">false</span><span class="p">)</span>
<a id="__codelineno-18-65" name="__codelineno-18-65" href="#__codelineno-18-65"></a> <span class="p">}</span>
<a id="__codelineno-18-66" name="__codelineno-18-66" href="#__codelineno-18-66"></a>
<a id="__codelineno-18-67" name="__codelineno-18-67" href="#__codelineno-18-67"></a> <span class="cm">/* 出队操作 */</span>
<a id="__codelineno-18-68" name="__codelineno-18-68" href="#__codelineno-18-68"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="nb">Bool</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-69" name="__codelineno-18-69" href="#__codelineno-18-69"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-18-70" name="__codelineno-18-70" href="#__codelineno-18-70"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-18-71" name="__codelineno-18-71" href="#__codelineno-18-71"></a> <span class="p">}</span>
<a id="__codelineno-18-72" name="__codelineno-18-72" href="#__codelineno-18-72"></a> <span class="kd">let</span> <span class="nv">val</span><span class="p">:</span> <span class="nb">Int</span>
<a id="__codelineno-18-73" name="__codelineno-18-73" href="#__codelineno-18-73"></a> <span class="c1">// 队首出队操作</span>
<a id="__codelineno-18-74" name="__codelineno-18-74" href="#__codelineno-18-74"></a> <span class="k">if</span> <span class="n">isFront</span> <span class="p">{</span>
<a id="__codelineno-18-75" name="__codelineno-18-75" href="#__codelineno-18-75"></a> <span class="n">val</span> <span class="p">=</span> <span class="n">front</span><span class="p">!.</span><span class="n">val</span> <span class="c1">// 暂存头节点值</span>
<a id="__codelineno-18-76" name="__codelineno-18-76" href="#__codelineno-18-76"></a> <span class="c1">// 删除头节点</span>
<a id="__codelineno-18-77" name="__codelineno-18-77" href="#__codelineno-18-77"></a> <span class="kd">let</span> <span class="nv">fNext</span> <span class="p">=</span> <span class="n">front</span><span class="p">?.</span><span class="n">next</span>
<a id="__codelineno-18-78" name="__codelineno-18-78" href="#__codelineno-18-78"></a> <span class="k">if</span> <span class="n">fNext</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
<a id="__codelineno-18-79" name="__codelineno-18-79" href="#__codelineno-18-79"></a> <span class="n">fNext</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-18-80" name="__codelineno-18-80" href="#__codelineno-18-80"></a> <span class="n">front</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-18-81" name="__codelineno-18-81" href="#__codelineno-18-81"></a> <span class="p">}</span>
<a id="__codelineno-18-82" name="__codelineno-18-82" href="#__codelineno-18-82"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">fNext</span> <span class="c1">// 更新头节点</span>
<a id="__codelineno-18-83" name="__codelineno-18-83" href="#__codelineno-18-83"></a> <span class="p">}</span>
<a id="__codelineno-18-84" name="__codelineno-18-84" href="#__codelineno-18-84"></a> <span class="c1">// 队尾出队操作</span>
<a id="__codelineno-18-85" name="__codelineno-18-85" href="#__codelineno-18-85"></a> <span class="k">else</span> <span class="p">{</span>
<a id="__codelineno-18-86" name="__codelineno-18-86" href="#__codelineno-18-86"></a> <span class="n">val</span> <span class="p">=</span> <span class="n">rear</span><span class="p">!.</span><span class="n">val</span> <span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-18-87" name="__codelineno-18-87" href="#__codelineno-18-87"></a> <span class="c1">// 删除尾节点</span>
<a id="__codelineno-18-88" name="__codelineno-18-88" href="#__codelineno-18-88"></a> <span class="kd">let</span> <span class="nv">rPrev</span> <span class="p">=</span> <span class="n">rear</span><span class="p">?.</span><span class="n">prev</span>
<a id="__codelineno-18-89" name="__codelineno-18-89" href="#__codelineno-18-89"></a> <span class="k">if</span> <span class="n">rPrev</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
<a id="__codelineno-18-90" name="__codelineno-18-90" href="#__codelineno-18-90"></a> <span class="n">rPrev</span><span class="p">?.</span><span class="n">next</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-18-91" name="__codelineno-18-91" href="#__codelineno-18-91"></a> <span class="n">rear</span><span class="p">?.</span><span class="n">prev</span> <span class="p">=</span> <span class="kc">nil</span>
<a id="__codelineno-18-92" name="__codelineno-18-92" href="#__codelineno-18-92"></a> <span class="p">}</span>
<a id="__codelineno-18-93" name="__codelineno-18-93" href="#__codelineno-18-93"></a> <span class="n">rear</span> <span class="p">=</span> <span class="n">rPrev</span> <span class="c1">// 更新尾节点</span>
<a id="__codelineno-18-94" name="__codelineno-18-94" href="#__codelineno-18-94"></a> <span class="p">}</span>
<a id="__codelineno-18-95" name="__codelineno-18-95" href="#__codelineno-18-95"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span> <span class="c1">// 更新队列长度</span>
<a id="__codelineno-18-96" name="__codelineno-18-96" href="#__codelineno-18-96"></a> <span class="k">return</span> <span class="n">val</span>
<a id="__codelineno-18-97" name="__codelineno-18-97" href="#__codelineno-18-97"></a> <span class="p">}</span>
<a id="__codelineno-18-98" name="__codelineno-18-98" href="#__codelineno-18-98"></a>
<a id="__codelineno-18-99" name="__codelineno-18-99" href="#__codelineno-18-99"></a> <span class="cm">/* 队首出队 */</span>
<a id="__codelineno-18-100" name="__codelineno-18-100" href="#__codelineno-18-100"></a> <span class="kd">func</span> <span class="nf">popFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-101" name="__codelineno-18-101" href="#__codelineno-18-101"></a> <span class="n">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="kc">true</span><span class="p">)</span>
<a id="__codelineno-18-102" name="__codelineno-18-102" href="#__codelineno-18-102"></a> <span class="p">}</span>
<a id="__codelineno-18-103" name="__codelineno-18-103" href="#__codelineno-18-103"></a>
<a id="__codelineno-18-104" name="__codelineno-18-104" href="#__codelineno-18-104"></a> <span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-18-105" name="__codelineno-18-105" href="#__codelineno-18-105"></a> <span class="kd">func</span> <span class="nf">popLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-18-106" name="__codelineno-18-106" href="#__codelineno-18-106"></a> <span class="n">pop</span><span class="p">(</span><span class="n">isFront</span><span class="p">:</span> <span class="kc">false</span><span class="p">)</span>
<a id="__codelineno-18-107" name="__codelineno-18-107" href="#__codelineno-18-107"></a> <span class="p">}</span>
<a id="__codelineno-18-108" name="__codelineno-18-108" href="#__codelineno-18-108"></a>
<a id="__codelineno-18-109" name="__codelineno-18-109" href="#__codelineno-18-109"></a> <span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-18-110" name="__codelineno-18-110" href="#__codelineno-18-110"></a> <span class="kd">func</span> <span class="nf">peekFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span><span class="p">?</span> <span class="p">{</span>
<a id="__codelineno-18-111" name="__codelineno-18-111" href="#__codelineno-18-111"></a> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">?</span> <span class="kc">nil</span> <span class="p">:</span> <span class="n">front</span><span class="p">?.</span><span class="n">val</span>
<a id="__codelineno-18-112" name="__codelineno-18-112" href="#__codelineno-18-112"></a> <span class="p">}</span>
<a id="__codelineno-18-113" name="__codelineno-18-113" href="#__codelineno-18-113"></a>
<a id="__codelineno-18-114" name="__codelineno-18-114" href="#__codelineno-18-114"></a> <span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-18-115" name="__codelineno-18-115" href="#__codelineno-18-115"></a> <span class="kd">func</span> <span class="nf">peekLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span><span class="p">?</span> <span class="p">{</span>
<a id="__codelineno-18-116" name="__codelineno-18-116" href="#__codelineno-18-116"></a> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">?</span> <span class="kc">nil</span> <span class="p">:</span> <span class="n">rear</span><span class="p">?.</span><span class="n">val</span>
<a id="__codelineno-18-117" name="__codelineno-18-117" href="#__codelineno-18-117"></a> <span class="p">}</span>
<a id="__codelineno-18-118" name="__codelineno-18-118" href="#__codelineno-18-118"></a>
<a id="__codelineno-18-119" name="__codelineno-18-119" href="#__codelineno-18-119"></a> <span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-18-120" name="__codelineno-18-120" href="#__codelineno-18-120"></a> <span class="kd">func</span> <span class="nf">toArray</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="p">{</span>
<a id="__codelineno-18-121" name="__codelineno-18-121" href="#__codelineno-18-121"></a> <span class="kd">var</span> <span class="nv">node</span> <span class="p">=</span> <span class="n">front</span>
<a id="__codelineno-18-122" name="__codelineno-18-122" href="#__codelineno-18-122"></a> <span class="kd">var</span> <span class="nv">res</span> <span class="p">=</span> <span class="nb">Array</span><span class="p">(</span><span class="n">repeating</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="bp">count</span><span class="p">:</span> <span class="n">size</span><span class="p">())</span>
<a id="__codelineno-18-123" name="__codelineno-18-123" href="#__codelineno-18-123"></a> <span class="k">for</span> <span class="n">i</span> <span class="k">in</span> <span class="n">res</span><span class="p">.</span><span class="bp">indices</span> <span class="p">{</span>
<a id="__codelineno-18-124" name="__codelineno-18-124" href="#__codelineno-18-124"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="p">=</span> <span class="n">node</span><span class="p">!.</span><span class="n">val</span>
<a id="__codelineno-18-125" name="__codelineno-18-125" href="#__codelineno-18-125"></a> <span class="n">node</span> <span class="p">=</span> <span class="n">node</span><span class="p">?.</span><span class="n">next</span>
<a id="__codelineno-18-126" name="__codelineno-18-126" href="#__codelineno-18-126"></a> <span class="p">}</span>
<a id="__codelineno-18-127" name="__codelineno-18-127" href="#__codelineno-18-127"></a> <span class="k">return</span> <span class="n">res</span>
<a id="__codelineno-18-128" name="__codelineno-18-128" href="#__codelineno-18-128"></a> <span class="p">}</span>
<a id="__codelineno-18-129" name="__codelineno-18-129" href="#__codelineno-18-129"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">linkedlist_deque.zig</span><pre><span></span><code><a id="__codelineno-19-1" name="__codelineno-19-1" href="#__codelineno-19-1"></a><span class="c1">// 双向链表节点</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">ListNode</span><span class="p">(</span><span class="kr">comptime</span><span class="w"> </span><span class="n">T</span><span class="o">:</span><span class="w"> </span><span class="kt">type</span><span class="p">)</span><span class="w"> </span><span class="kt">type</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">val</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">,</span><span class="w"> </span><span class="c1">// 节点值</span>
<a id="__codelineno-19-7" name="__codelineno-19-7" href="#__codelineno-19-7"></a><span class="w"> </span><span class="n">next</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 后继节点引用（指针）</span>
<a id="__codelineno-19-8" name="__codelineno-19-8" href="#__codelineno-19-8"></a><span class="w"> </span><span class="n">prev</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 前驱节点引用（指针）</span>
<a id="__codelineno-19-9" name="__codelineno-19-9" href="#__codelineno-19-9"></a>
<a id="__codelineno-19-10" name="__codelineno-19-10" href="#__codelineno-19-10"></a><span class="w"> </span><span class="c1">// Initialize a list node with specific value</span>
<a id="__codelineno-19-11" name="__codelineno-19-11" href="#__codelineno-19-11"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">init</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">x</span><span class="o">:</span><span class="w"> </span><span class="kt">i32</span><span class="p">)</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-12" name="__codelineno-19-12" href="#__codelineno-19-12"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">x</span><span class="p">;</span>
<a id="__codelineno-19-13" name="__codelineno-19-13" href="#__codelineno-19-13"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-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">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-15" name="__codelineno-19-15" href="#__codelineno-19-15"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-16" name="__codelineno-19-16" href="#__codelineno-19-16"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-19-17" name="__codelineno-19-17" href="#__codelineno-19-17"></a><span class="p">}</span>
<a id="__codelineno-19-18" name="__codelineno-19-18" href="#__codelineno-19-18"></a>
<a id="__codelineno-19-19" name="__codelineno-19-19" href="#__codelineno-19-19"></a><span class="c1">// 基于双向链表实现的双向队列</span>
<a id="__codelineno-19-20" name="__codelineno-19-20" href="#__codelineno-19-20"></a><span class="k">fn</span><span class="w"> </span><span class="n">LinkedListDeque</span><span class="p">(</span><span class="kr">comptime</span><span class="w"> </span><span class="n">T</span><span class="o">:</span><span class="w"> </span><span class="kt">type</span><span class="p">)</span><span class="w"> </span><span class="kt">type</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-21" name="__codelineno-19-21" href="#__codelineno-19-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-22" name="__codelineno-19-22" href="#__codelineno-19-22"></a><span class="w"> </span><span class="kr">const</span><span class="w"> </span><span class="n">Self</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">@This</span><span class="p">();</span>
<a id="__codelineno-19-23" name="__codelineno-19-23" href="#__codelineno-19-23"></a>
<a id="__codelineno-19-24" name="__codelineno-19-24" href="#__codelineno-19-24"></a><span class="w"> </span><span class="n">front</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 头节点 front</span>
<a id="__codelineno-19-25" name="__codelineno-19-25" href="#__codelineno-19-25"></a><span class="w"> </span><span class="n">rear</span><span class="o">:</span><span class="w"> </span><span class="o">?*</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span><span class="w"> </span><span class="c1">// 尾节点 rear</span>
<a id="__codelineno-19-26" name="__codelineno-19-26" href="#__codelineno-19-26"></a><span class="w"> </span><span class="n">que_size</span><span class="o">:</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="c1">// 双向队列的长度</span>
<a id="__codelineno-19-27" name="__codelineno-19-27" href="#__codelineno-19-27"></a><span class="w"> </span><span class="n">mem_arena</span><span class="o">:</span><span class="w"> </span><span class="o">?</span><span class="n">std</span><span class="p">.</span><span class="n">heap</span><span class="p">.</span><span class="n">ArenaAllocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">,</span>
<a id="__codelineno-19-28" name="__codelineno-19-28" href="#__codelineno-19-28"></a><span class="w"> </span><span class="n">mem_allocator</span><span class="o">:</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">mem</span><span class="p">.</span><span class="n">Allocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">,</span><span class="w"> </span><span class="c1">// 内存分配器</span>
<a id="__codelineno-19-29" name="__codelineno-19-29" href="#__codelineno-19-29"></a>
<a id="__codelineno-19-30" name="__codelineno-19-30" href="#__codelineno-19-30"></a><span class="w"> </span><span class="c1">// 构造方法（分配内存+初始化队列）</span>
<a id="__codelineno-19-31" name="__codelineno-19-31" href="#__codelineno-19-31"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">init</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">allocator</span><span class="o">:</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">mem</span><span class="p">.</span><span class="n">Allocator</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-32" name="__codelineno-19-32" href="#__codelineno-19-32"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-33" name="__codelineno-19-33" href="#__codelineno-19-33"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">std</span><span class="p">.</span><span class="n">heap</span><span class="p">.</span><span class="n">ArenaAllocator</span><span class="p">.</span><span class="n">init</span><span class="p">(</span><span class="n">allocator</span><span class="p">);</span>
<a id="__codelineno-19-34" name="__codelineno-19-34" href="#__codelineno-19-34"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">allocator</span><span class="p">();</span>
<a id="__codelineno-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><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-37" name="__codelineno-19-37" href="#__codelineno-19-37"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-38" name="__codelineno-19-38" href="#__codelineno-19-38"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-19-39" name="__codelineno-19-39" href="#__codelineno-19-39"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-40" name="__codelineno-19-40" href="#__codelineno-19-40"></a>
<a id="__codelineno-19-41" name="__codelineno-19-41" href="#__codelineno-19-41"></a><span class="w"> </span><span class="c1">// 析构方法（释放内存）</span>
<a id="__codelineno-19-42" name="__codelineno-19-42" href="#__codelineno-19-42"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">deinit</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-43" name="__codelineno-19-43" href="#__codelineno-19-43"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-19-44" name="__codelineno-19-44" href="#__codelineno-19-44"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_arena</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">deinit</span><span class="p">();</span>
<a id="__codelineno-19-45" name="__codelineno-19-45" href="#__codelineno-19-45"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-46" name="__codelineno-19-46" href="#__codelineno-19-46"></a>
<a id="__codelineno-19-47" name="__codelineno-19-47" href="#__codelineno-19-47"></a><span class="w"> </span><span class="c1">// 获取双向队列的长度</span>
<a id="__codelineno-19-48" name="__codelineno-19-48" href="#__codelineno-19-48"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">size</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-49" name="__codelineno-19-49" href="#__codelineno-19-49"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="p">;</span>
<a id="__codelineno-19-50" name="__codelineno-19-50" href="#__codelineno-19-50"></a><span class="w"> </span><span class="p">}</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">// 判断双向队列是否为空</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">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-19-54" name="__codelineno-19-54" href="#__codelineno-19-54"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-19-55" name="__codelineno-19-55" href="#__codelineno-19-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-56" name="__codelineno-19-56" href="#__codelineno-19-56"></a>
<a id="__codelineno-19-57" name="__codelineno-19-57" href="#__codelineno-19-57"></a><span class="w"> </span><span class="c1">// 入队操作</span>
<a id="__codelineno-19-58" name="__codelineno-19-58" href="#__codelineno-19-58"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">push</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span><span class="o">:</span><span class="w"> </span><span class="kt">bool</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-59" name="__codelineno-19-59" href="#__codelineno-19-59"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="p">.</span><span class="n">create</span><span class="p">(</span><span class="n">ListNode</span><span class="p">(</span><span class="n">T</span><span class="p">));</span>
<a id="__codelineno-19-60" name="__codelineno-19-60" href="#__codelineno-19-60"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">init</span><span class="p">(</span><span class="n">num</span><span class="p">);</span>
<a id="__codelineno-19-61" name="__codelineno-19-61" href="#__codelineno-19-61"></a><span class="w"> </span><span class="c1">// 若链表为空，则令 front, rear 都指向 node</span>
<a id="__codelineno-19-62" name="__codelineno-19-62" href="#__codelineno-19-62"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-63" name="__codelineno-19-63" href="#__codelineno-19-63"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-19-64" name="__codelineno-19-64" href="#__codelineno-19-64"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-19-65" name="__codelineno-19-65" href="#__codelineno-19-65"></a><span class="w"> </span><span class="c1">// 队首入队操作</span>
<a id="__codelineno-19-66" name="__codelineno-19-66" href="#__codelineno-19-66"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">is_front</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-67" name="__codelineno-19-67" href="#__codelineno-19-67"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表头部</span>
<a id="__codelineno-19-68" name="__codelineno-19-68" href="#__codelineno-19-68"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-19-69" name="__codelineno-19-69" href="#__codelineno-19-69"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-19-70" name="__codelineno-19-70" href="#__codelineno-19-70"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-19-71" name="__codelineno-19-71" href="#__codelineno-19-71"></a><span class="w"> </span><span class="c1">// 队尾入队操作</span>
<a id="__codelineno-19-72" name="__codelineno-19-72" href="#__codelineno-19-72"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-73" name="__codelineno-19-73" href="#__codelineno-19-73"></a><span class="w"> </span><span class="c1">// 将 node 添加至链表尾部</span>
<a id="__codelineno-19-74" name="__codelineno-19-74" href="#__codelineno-19-74"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span>
<a id="__codelineno-19-75" name="__codelineno-19-75" href="#__codelineno-19-75"></a><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">;</span>
<a id="__codelineno-19-76" name="__codelineno-19-76" href="#__codelineno-19-76"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-19-77" name="__codelineno-19-77" href="#__codelineno-19-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-78" name="__codelineno-19-78" href="#__codelineno-19-78"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-19-79" name="__codelineno-19-79" href="#__codelineno-19-79"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-80" name="__codelineno-19-80" href="#__codelineno-19-80"></a>
<a id="__codelineno-19-81" name="__codelineno-19-81" href="#__codelineno-19-81"></a><span class="w"> </span><span class="c1">// 队首入队</span>
<a id="__codelineno-19-82" name="__codelineno-19-82" href="#__codelineno-19-82"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-83" name="__codelineno-19-83" href="#__codelineno-19-83"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-19-84" name="__codelineno-19-84" href="#__codelineno-19-84"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-85" name="__codelineno-19-85" href="#__codelineno-19-85"></a>
<a id="__codelineno-19-86" name="__codelineno-19-86" href="#__codelineno-19-86"></a><span class="w"> </span><span class="c1">// 队尾入队</span>
<a id="__codelineno-19-87" name="__codelineno-19-87" href="#__codelineno-19-87"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">num</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="kt">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-88" name="__codelineno-19-88" href="#__codelineno-19-88"></a><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">num</span><span class="p">,</span><span class="w"> </span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-19-89" name="__codelineno-19-89" href="#__codelineno-19-89"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-90" name="__codelineno-19-90" href="#__codelineno-19-90"></a>
<a id="__codelineno-19-91" name="__codelineno-19-91" href="#__codelineno-19-91"></a><span class="w"> </span><span class="c1">// 出队操作</span>
<a id="__codelineno-19-92" name="__codelineno-19-92" href="#__codelineno-19-92"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">pop</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">,</span><span class="w"> </span><span class="n">is_front</span><span class="o">:</span><span class="w"> </span><span class="kt">bool</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-93" name="__codelineno-19-93" href="#__codelineno-19-93"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-19-94" name="__codelineno-19-94" href="#__codelineno-19-94"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">val</span><span class="o">:</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">undefined</span><span class="p">;</span>
<a id="__codelineno-19-95" name="__codelineno-19-95" href="#__codelineno-19-95"></a><span class="w"> </span><span class="c1">// 队首出队操作</span>
<a id="__codelineno-19-96" name="__codelineno-19-96" href="#__codelineno-19-96"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">is_front</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-97" name="__codelineno-19-97" href="#__codelineno-19-97"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存头节点值</span>
<a id="__codelineno-19-98" name="__codelineno-19-98" href="#__codelineno-19-98"></a><span class="w"> </span><span class="c1">// 删除头节点</span>
<a id="__codelineno-19-99" name="__codelineno-19-99" href="#__codelineno-19-99"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">fNext</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-19-100" name="__codelineno-19-100" href="#__codelineno-19-100"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">fNext</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-101" name="__codelineno-19-101" href="#__codelineno-19-101"></a><span class="w"> </span><span class="n">fNext</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-102" name="__codelineno-19-102" href="#__codelineno-19-102"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-103" name="__codelineno-19-103" href="#__codelineno-19-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-104" name="__codelineno-19-104" href="#__codelineno-19-104"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">fNext</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新头节点</span>
<a id="__codelineno-19-105" name="__codelineno-19-105" href="#__codelineno-19-105"></a><span class="w"> </span><span class="c1">// 队尾出队操作</span>
<a id="__codelineno-19-106" name="__codelineno-19-106" href="#__codelineno-19-106"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-107" name="__codelineno-19-107" href="#__codelineno-19-107"></a><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span><span class="w"> </span><span class="c1">// 暂存尾节点值</span>
<a id="__codelineno-19-108" name="__codelineno-19-108" href="#__codelineno-19-108"></a><span class="w"> </span><span class="c1">// 删除尾节点</span>
<a id="__codelineno-19-109" name="__codelineno-19-109" href="#__codelineno-19-109"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">rPrev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="p">;</span>
<a id="__codelineno-19-110" name="__codelineno-19-110" href="#__codelineno-19-110"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">rPrev</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="kc">null</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-111" name="__codelineno-19-111" href="#__codelineno-19-111"></a><span class="w"> </span><span class="n">rPrev</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-112" name="__codelineno-19-112" href="#__codelineno-19-112"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">prev</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<a id="__codelineno-19-113" name="__codelineno-19-113" href="#__codelineno-19-113"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-114" name="__codelineno-19-114" href="#__codelineno-19-114"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">rPrev</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新尾节点</span>
<a id="__codelineno-19-115" name="__codelineno-19-115" href="#__codelineno-19-115"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-116" name="__codelineno-19-116" href="#__codelineno-19-116"></a><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">que_size</span><span class="w"> </span><span class="o">-=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span><span class="w"> </span><span class="c1">// 更新队列长度</span>
<a id="__codelineno-19-117" name="__codelineno-19-117" href="#__codelineno-19-117"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-19-118" name="__codelineno-19-118" href="#__codelineno-19-118"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-119" name="__codelineno-19-119" href="#__codelineno-19-119"></a>
<a id="__codelineno-19-120" name="__codelineno-19-120" href="#__codelineno-19-120"></a><span class="w"> </span><span class="c1">// 队首出队</span>
<a id="__codelineno-19-121" name="__codelineno-19-121" href="#__codelineno-19-121"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">popFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-122" name="__codelineno-19-122" href="#__codelineno-19-122"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<a id="__codelineno-19-123" name="__codelineno-19-123" href="#__codelineno-19-123"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-124" name="__codelineno-19-124" href="#__codelineno-19-124"></a>
<a id="__codelineno-19-125" name="__codelineno-19-125" href="#__codelineno-19-125"></a><span class="w"> </span><span class="c1">// 队尾出队</span>
<a id="__codelineno-19-126" name="__codelineno-19-126" href="#__codelineno-19-126"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">popLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-127" name="__codelineno-19-127" href="#__codelineno-19-127"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">pop</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<a id="__codelineno-19-128" name="__codelineno-19-128" href="#__codelineno-19-128"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-129" name="__codelineno-19-129" href="#__codelineno-19-129"></a>
<a id="__codelineno-19-130" name="__codelineno-19-130" href="#__codelineno-19-130"></a><span class="w"> </span><span class="c1">// 访问队首元素</span>
<a id="__codelineno-19-131" name="__codelineno-19-131" href="#__codelineno-19-131"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-132" name="__codelineno-19-132" href="#__codelineno-19-132"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-19-133" name="__codelineno-19-133" href="#__codelineno-19-133"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-19-134" name="__codelineno-19-134" href="#__codelineno-19-134"></a><span class="w"> </span><span class="p">}</span><span class="w"> </span>
<a id="__codelineno-19-135" name="__codelineno-19-135" href="#__codelineno-19-135"></a>
<a id="__codelineno-19-136" name="__codelineno-19-136" href="#__codelineno-19-136"></a><span class="w"> </span><span class="c1">// 访问队尾元素</span>
<a id="__codelineno-19-137" name="__codelineno-19-137" href="#__codelineno-19-137"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-138" name="__codelineno-19-138" href="#__codelineno-19-138"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">self</span><span class="p">.</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="nb">@panic</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-19-139" name="__codelineno-19-139" href="#__codelineno-19-139"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">rear</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-19-140" name="__codelineno-19-140" href="#__codelineno-19-140"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-141" name="__codelineno-19-141" href="#__codelineno-19-141"></a>
<a id="__codelineno-19-142" name="__codelineno-19-142" href="#__codelineno-19-142"></a><span class="w"> </span><span class="c1">// 返回数组用于打印</span>
<a id="__codelineno-19-143" name="__codelineno-19-143" href="#__codelineno-19-143"></a><span class="w"> </span><span class="kr">pub</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">toArray</span><span class="p">(</span><span class="n">self</span><span class="o">:</span><span class="w"> </span><span class="o">*</span><span class="n">Self</span><span class="p">)</span><span class="w"> </span><span class="o">!</span><span class="p">[]</span><span class="n">T</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-144" name="__codelineno-19-144" href="#__codelineno-19-144"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">front</span><span class="p">;</span>
<a id="__codelineno-19-145" name="__codelineno-19-145" href="#__codelineno-19-145"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">mem_allocator</span><span class="p">.</span><span class="n">alloc</span><span class="p">(</span><span class="n">T</span><span class="p">,</span><span class="w"> </span><span class="n">self</span><span class="p">.</span><span class="n">size</span><span class="p">());</span>
<a id="__codelineno-19-146" name="__codelineno-19-146" href="#__codelineno-19-146"></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-19-147" name="__codelineno-19-147" href="#__codelineno-19-147"></a><span class="w"> </span><span class="kr">var</span><span class="w"> </span><span class="n">i</span><span class="o">:</span><span class="w"> </span><span class="kt">usize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-19-148" name="__codelineno-19-148" href="#__codelineno-19-148"></a><span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">res</span><span class="p">.</span><span class="n">len</span><span class="p">)</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-19-149" name="__codelineno-19-149" href="#__codelineno-19-149"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">val</span><span class="p">;</span>
<a id="__codelineno-19-150" name="__codelineno-19-150" href="#__codelineno-19-150"></a><span class="w"> </span><span class="n">node</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">node</span><span class="p">.</span><span class="o">?</span><span class="p">.</span><span class="n">next</span><span class="p">;</span>
<a id="__codelineno-19-151" name="__codelineno-19-151" href="#__codelineno-19-151"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-152" name="__codelineno-19-152" href="#__codelineno-19-152"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-19-153" name="__codelineno-19-153" href="#__codelineno-19-153"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-19-154" name="__codelineno-19-154" href="#__codelineno-19-154"></a><span class="w"> </span><span class="p">};</span>
<a id="__codelineno-19-155" name="__codelineno-19-155" href="#__codelineno-19-155"></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>与基于数组实现队列类似，我们也可以使用环形数组来实现双向队列。在队列的实现基础上，仅需增加“队首入队”和“队尾出队”的方法。</p>
<div class="tabbed-set tabbed-alternate" data-tabs="4:5"><input checked="checked" id="__tabbed_4_1" name="__tabbed_4" type="radio" /><input id="__tabbed_4_2" name="__tabbed_4" type="radio" /><input id="__tabbed_4_3" name="__tabbed_4" type="radio" /><input id="__tabbed_4_4" name="__tabbed_4" type="radio" /><input id="__tabbed_4_5" name="__tabbed_4" type="radio" /><div class="tabbed-labels"><label for="__tabbed_4_1">ArrayDeque</label><label for="__tabbed_4_2">pushLast()</label><label for="__tabbed_4_3">pushFirst()</label><label for="__tabbed_4_4">popLast()</label><label for="__tabbed_4_5">popFirst()</label></div>
<div class="tabbed-content">
<div class="tabbed-block">
<p><img alt="基于数组实现双向队列的入队出队操作" src="../deque.assets/array_deque.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_deque_push_last" src="../deque.assets/array_deque_push_last.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_deque_push_first" src="../deque.assets/array_deque_push_first.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_deque_pop_last" src="../deque.assets/array_deque_pop_last.png" /></p>
</div>
<div class="tabbed-block">
<p><img alt="array_deque_pop_first" src="../deque.assets/array_deque_pop_first.png" /></p>
</div>
</div>
</div>
<p>以下是具体实现代码。</p>
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<div class="highlight"><span class="filename">array_deque.java</span><pre><span></span><code><a id="__codelineno-20-1" name="__codelineno-20-1" href="#__codelineno-20-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-20-2" name="__codelineno-20-2" href="#__codelineno-20-2"></a><span class="kd">class</span> <span class="nc">ArrayDeque</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="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-20-4" name="__codelineno-20-4" href="#__codelineno-20-4"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-20-5" name="__codelineno-20-5" href="#__codelineno-20-5"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-20-6" name="__codelineno-20-6" href="#__codelineno-20-6"></a>
<a id="__codelineno-20-7" name="__codelineno-20-7" href="#__codelineno-20-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-20-8" name="__codelineno-20-8" href="#__codelineno-20-8"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="nf">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-9" name="__codelineno-20-9" href="#__codelineno-20-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="na">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="o">[</span><span class="n">capacity</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-20-10" name="__codelineno-20-10" href="#__codelineno-20-10"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-20-11" name="__codelineno-20-11" href="#__codelineno-20-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-12" name="__codelineno-20-12" href="#__codelineno-20-12"></a>
<a id="__codelineno-20-13" name="__codelineno-20-13" href="#__codelineno-20-13"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-20-14" name="__codelineno-20-14" href="#__codelineno-20-14"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-15" name="__codelineno-20-15" href="#__codelineno-20-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="na">length</span><span class="p">;</span>
<a id="__codelineno-20-16" name="__codelineno-20-16" href="#__codelineno-20-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-17" name="__codelineno-20-17" href="#__codelineno-20-17"></a>
<a id="__codelineno-20-18" name="__codelineno-20-18" href="#__codelineno-20-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-20-19" name="__codelineno-20-19" href="#__codelineno-20-19"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-20" name="__codelineno-20-20" href="#__codelineno-20-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-20-21" name="__codelineno-20-21" href="#__codelineno-20-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-22" name="__codelineno-20-22" href="#__codelineno-20-22"></a>
<a id="__codelineno-20-23" name="__codelineno-20-23" href="#__codelineno-20-23"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-20-24" name="__codelineno-20-24" href="#__codelineno-20-24"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-25" name="__codelineno-20-25" href="#__codelineno-20-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-20-26" name="__codelineno-20-26" href="#__codelineno-20-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-27" name="__codelineno-20-27" href="#__codelineno-20-27"></a>
<a id="__codelineno-20-28" name="__codelineno-20-28" href="#__codelineno-20-28"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-20-29" name="__codelineno-20-29" href="#__codelineno-20-29"></a><span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-30" name="__codelineno-20-30" href="#__codelineno-20-30"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-20-31" name="__codelineno-20-31" href="#__codelineno-20-31"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-20-32" name="__codelineno-20-32" href="#__codelineno-20-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-20-33" name="__codelineno-20-33" href="#__codelineno-20-33"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-20-34" name="__codelineno-20-34" href="#__codelineno-20-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-35" name="__codelineno-20-35" href="#__codelineno-20-35"></a>
<a id="__codelineno-20-36" name="__codelineno-20-36" href="#__codelineno-20-36"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-20-37" name="__codelineno-20-37" href="#__codelineno-20-37"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-38" name="__codelineno-20-38" href="#__codelineno-20-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-39" name="__codelineno-20-39" href="#__codelineno-20-39"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-20-40" name="__codelineno-20-40" href="#__codelineno-20-40"></a><span class="w"> </span><span class="k">return</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="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-20-43" name="__codelineno-20-43" href="#__codelineno-20-43"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-20-44" name="__codelineno-20-44" href="#__codelineno-20-44"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-20-45" name="__codelineno-20-45" href="#__codelineno-20-45"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-20-46" name="__codelineno-20-46" href="#__codelineno-20-46"></a><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">front</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-20-47" name="__codelineno-20-47" href="#__codelineno-20-47"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-20-48" name="__codelineno-20-48" href="#__codelineno-20-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-49" name="__codelineno-20-49" href="#__codelineno-20-49"></a>
<a id="__codelineno-20-50" name="__codelineno-20-50" href="#__codelineno-20-50"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-20-51" name="__codelineno-20-51" href="#__codelineno-20-51"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-52" name="__codelineno-20-52" href="#__codelineno-20-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-53" name="__codelineno-20-53" href="#__codelineno-20-53"></a><span class="w"> </span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">.</span><span class="na">println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-20-54" name="__codelineno-20-54" href="#__codelineno-20-54"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-20-55" name="__codelineno-20-55" href="#__codelineno-20-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-56" name="__codelineno-20-56" href="#__codelineno-20-56"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-20-57" name="__codelineno-20-57" href="#__codelineno-20-57"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-20-58" name="__codelineno-20-58" href="#__codelineno-20-58"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-20-59" name="__codelineno-20-59" href="#__codelineno-20-59"></a><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">rear</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-20-60" name="__codelineno-20-60" href="#__codelineno-20-60"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-20-61" name="__codelineno-20-61" href="#__codelineno-20-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-62" name="__codelineno-20-62" href="#__codelineno-20-62"></a>
<a id="__codelineno-20-63" name="__codelineno-20-63" href="#__codelineno-20-63"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-20-64" name="__codelineno-20-64" href="#__codelineno-20-64"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-65" name="__codelineno-20-65" href="#__codelineno-20-65"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-20-66" name="__codelineno-20-66" href="#__codelineno-20-66"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-20-67" name="__codelineno-20-67" href="#__codelineno-20-67"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-20-68" name="__codelineno-20-68" href="#__codelineno-20-68"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-20-69" name="__codelineno-20-69" href="#__codelineno-20-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-20-70" name="__codelineno-20-70" href="#__codelineno-20-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-71" name="__codelineno-20-71" href="#__codelineno-20-71"></a>
<a id="__codelineno-20-72" name="__codelineno-20-72" href="#__codelineno-20-72"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-20-73" name="__codelineno-20-73" href="#__codelineno-20-73"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-74" name="__codelineno-20-74" href="#__codelineno-20-74"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-20-75" name="__codelineno-20-75" href="#__codelineno-20-75"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-20-76" name="__codelineno-20-76" href="#__codelineno-20-76"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-20-77" name="__codelineno-20-77" href="#__codelineno-20-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-78" name="__codelineno-20-78" href="#__codelineno-20-78"></a>
<a id="__codelineno-20-79" name="__codelineno-20-79" href="#__codelineno-20-79"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-20-80" name="__codelineno-20-80" href="#__codelineno-20-80"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-81" name="__codelineno-20-81" href="#__codelineno-20-81"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-20-82" name="__codelineno-20-82" href="#__codelineno-20-82"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-20-83" name="__codelineno-20-83" href="#__codelineno-20-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">front</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-20-84" name="__codelineno-20-84" href="#__codelineno-20-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-85" name="__codelineno-20-85" href="#__codelineno-20-85"></a>
<a id="__codelineno-20-86" name="__codelineno-20-86" href="#__codelineno-20-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-20-87" name="__codelineno-20-87" href="#__codelineno-20-87"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-88" name="__codelineno-20-88" href="#__codelineno-20-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-20-89" name="__codelineno-20-89" href="#__codelineno-20-89"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">IndexOutOfBoundsException</span><span class="p">();</span>
<a id="__codelineno-20-90" name="__codelineno-20-90" href="#__codelineno-20-90"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-20-91" name="__codelineno-20-91" href="#__codelineno-20-91"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-20-92" name="__codelineno-20-92" href="#__codelineno-20-92"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">last</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-20-93" name="__codelineno-20-93" href="#__codelineno-20-93"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-94" name="__codelineno-20-94" href="#__codelineno-20-94"></a>
<a id="__codelineno-20-95" name="__codelineno-20-95" href="#__codelineno-20-95"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-20-96" name="__codelineno-20-96" href="#__codelineno-20-96"></a><span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="nf">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-97" name="__codelineno-20-97" href="#__codelineno-20-97"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-20-98" name="__codelineno-20-98" href="#__codelineno-20-98"></a><span class="w"> </span><span class="kt">int</span><span class="o">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="o">[</span><span class="n">queSize</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-20-99" name="__codelineno-20-99" href="#__codelineno-20-99"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-20-100" name="__codelineno-20-100" href="#__codelineno-20-100"></a><span class="w"> </span><span class="n">res</span><span class="o">[</span><span class="n">i</span><span class="o">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="o">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)</span><span class="o">]</span><span class="p">;</span>
<a id="__codelineno-20-101" name="__codelineno-20-101" href="#__codelineno-20-101"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-102" name="__codelineno-20-102" href="#__codelineno-20-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-20-103" name="__codelineno-20-103" href="#__codelineno-20-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-20-104" name="__codelineno-20-104" href="#__codelineno-20-104"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.cpp</span><pre><span></span><code><a id="__codelineno-21-1" name="__codelineno-21-1" href="#__codelineno-21-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</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">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-3" name="__codelineno-21-3" href="#__codelineno-21-3"></a><span class="w"> </span><span class="k">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">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-21-5" name="__codelineno-21-5" href="#__codelineno-21-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-21-6" name="__codelineno-21-6" href="#__codelineno-21-6"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-21-7" name="__codelineno-21-7" href="#__codelineno-21-7"></a>
<a id="__codelineno-21-8" name="__codelineno-21-8" href="#__codelineno-21-8"></a><span class="w"> </span><span class="k">public</span><span class="o">:</span>
<a id="__codelineno-21-9" name="__codelineno-21-9" href="#__codelineno-21-9"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-21-10" name="__codelineno-21-10" href="#__codelineno-21-10"></a><span class="w"> </span><span class="n">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-11" name="__codelineno-21-11" href="#__codelineno-21-11"></a><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">resize</span><span class="p">(</span><span class="n">capacity</span><span class="p">);</span>
<a id="__codelineno-21-12" name="__codelineno-21-12" href="#__codelineno-21-12"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-21-13" name="__codelineno-21-13" href="#__codelineno-21-13"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-14" name="__codelineno-21-14" href="#__codelineno-21-14"></a>
<a id="__codelineno-21-15" name="__codelineno-21-15" href="#__codelineno-21-15"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-21-16" name="__codelineno-21-16" href="#__codelineno-21-16"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-17" name="__codelineno-21-17" href="#__codelineno-21-17"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">size</span><span class="p">();</span>
<a id="__codelineno-21-18" name="__codelineno-21-18" href="#__codelineno-21-18"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-19" name="__codelineno-21-19" href="#__codelineno-21-19"></a>
<a id="__codelineno-21-20" name="__codelineno-21-20" href="#__codelineno-21-20"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-21-21" name="__codelineno-21-21" href="#__codelineno-21-21"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-22" name="__codelineno-21-22" href="#__codelineno-21-22"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-21-23" name="__codelineno-21-23" href="#__codelineno-21-23"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-24" name="__codelineno-21-24" href="#__codelineno-21-24"></a>
<a id="__codelineno-21-25" name="__codelineno-21-25" href="#__codelineno-21-25"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-21-26" name="__codelineno-21-26" href="#__codelineno-21-26"></a><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-27" name="__codelineno-21-27" href="#__codelineno-21-27"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-21-28" name="__codelineno-21-28" href="#__codelineno-21-28"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-29" name="__codelineno-21-29" href="#__codelineno-21-29"></a>
<a id="__codelineno-21-30" name="__codelineno-21-30" href="#__codelineno-21-30"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-21-31" name="__codelineno-21-31" href="#__codelineno-21-31"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-32" name="__codelineno-21-32" href="#__codelineno-21-32"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-21-33" name="__codelineno-21-33" href="#__codelineno-21-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-21-34" name="__codelineno-21-34" href="#__codelineno-21-34"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-21-35" name="__codelineno-21-35" href="#__codelineno-21-35"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-21-36" name="__codelineno-21-36" href="#__codelineno-21-36"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-37" name="__codelineno-21-37" href="#__codelineno-21-37"></a>
<a id="__codelineno-21-38" name="__codelineno-21-38" href="#__codelineno-21-38"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-21-39" name="__codelineno-21-39" href="#__codelineno-21-39"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-40" name="__codelineno-21-40" href="#__codelineno-21-40"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-41" name="__codelineno-21-41" href="#__codelineno-21-41"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot;双向队列已满&quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-21-42" name="__codelineno-21-42" href="#__codelineno-21-42"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-21-43" name="__codelineno-21-43" href="#__codelineno-21-43"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-44" name="__codelineno-21-44" href="#__codelineno-21-44"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-21-45" name="__codelineno-21-45" href="#__codelineno-21-45"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-21-46" name="__codelineno-21-46" href="#__codelineno-21-46"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-21-47" name="__codelineno-21-47" href="#__codelineno-21-47"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-21-48" name="__codelineno-21-48" href="#__codelineno-21-48"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-21-49" name="__codelineno-21-49" href="#__codelineno-21-49"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-21-50" name="__codelineno-21-50" href="#__codelineno-21-50"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-51" name="__codelineno-21-51" href="#__codelineno-21-51"></a>
<a id="__codelineno-21-52" name="__codelineno-21-52" href="#__codelineno-21-52"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-21-53" name="__codelineno-21-53" href="#__codelineno-21-53"></a><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="n">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-54" name="__codelineno-21-54" href="#__codelineno-21-54"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-55" name="__codelineno-21-55" href="#__codelineno-21-55"></a><span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="s">&quot;双向队列已满&quot;</span><span class="w"> </span><span class="o">&lt;&lt;</span><span class="w"> </span><span class="n">endl</span><span class="p">;</span>
<a id="__codelineno-21-56" name="__codelineno-21-56" href="#__codelineno-21-56"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-21-57" name="__codelineno-21-57" href="#__codelineno-21-57"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-58" name="__codelineno-21-58" href="#__codelineno-21-58"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-21-59" name="__codelineno-21-59" href="#__codelineno-21-59"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-21-60" name="__codelineno-21-60" href="#__codelineno-21-60"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-21-61" name="__codelineno-21-61" href="#__codelineno-21-61"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-21-62" name="__codelineno-21-62" href="#__codelineno-21-62"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-21-63" name="__codelineno-21-63" href="#__codelineno-21-63"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-64" name="__codelineno-21-64" href="#__codelineno-21-64"></a>
<a id="__codelineno-21-65" name="__codelineno-21-65" href="#__codelineno-21-65"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-21-66" name="__codelineno-21-66" href="#__codelineno-21-66"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-67" name="__codelineno-21-67" href="#__codelineno-21-67"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-21-68" name="__codelineno-21-68" href="#__codelineno-21-68"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-21-69" name="__codelineno-21-69" href="#__codelineno-21-69"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-21-70" name="__codelineno-21-70" href="#__codelineno-21-70"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-21-71" name="__codelineno-21-71" href="#__codelineno-21-71"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-21-72" name="__codelineno-21-72" href="#__codelineno-21-72"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-73" name="__codelineno-21-73" href="#__codelineno-21-73"></a>
<a id="__codelineno-21-74" name="__codelineno-21-74" href="#__codelineno-21-74"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-21-75" name="__codelineno-21-75" href="#__codelineno-21-75"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-76" name="__codelineno-21-76" href="#__codelineno-21-76"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-21-77" name="__codelineno-21-77" href="#__codelineno-21-77"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-21-78" name="__codelineno-21-78" href="#__codelineno-21-78"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-21-79" name="__codelineno-21-79" href="#__codelineno-21-79"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-80" name="__codelineno-21-80" href="#__codelineno-21-80"></a>
<a id="__codelineno-21-81" name="__codelineno-21-81" href="#__codelineno-21-81"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-21-82" name="__codelineno-21-82" href="#__codelineno-21-82"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-83" name="__codelineno-21-83" href="#__codelineno-21-83"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-21-84" name="__codelineno-21-84" href="#__codelineno-21-84"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-21-85" name="__codelineno-21-85" href="#__codelineno-21-85"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-21-86" name="__codelineno-21-86" href="#__codelineno-21-86"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-87" name="__codelineno-21-87" href="#__codelineno-21-87"></a>
<a id="__codelineno-21-88" name="__codelineno-21-88" href="#__codelineno-21-88"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-21-89" name="__codelineno-21-89" href="#__codelineno-21-89"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-90" name="__codelineno-21-90" href="#__codelineno-21-90"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span>
<a id="__codelineno-21-91" name="__codelineno-21-91" href="#__codelineno-21-91"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="n">out_of_range</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">);</span>
<a id="__codelineno-21-92" name="__codelineno-21-92" href="#__codelineno-21-92"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-21-93" name="__codelineno-21-93" href="#__codelineno-21-93"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-21-94" name="__codelineno-21-94" href="#__codelineno-21-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-21-95" name="__codelineno-21-95" href="#__codelineno-21-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-96" name="__codelineno-21-96" href="#__codelineno-21-96"></a>
<a id="__codelineno-21-97" name="__codelineno-21-97" href="#__codelineno-21-97"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-21-98" name="__codelineno-21-98" href="#__codelineno-21-98"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">toVector</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-99" name="__codelineno-21-99" href="#__codelineno-21-99"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-21-100" name="__codelineno-21-100" href="#__codelineno-21-100"></a><span class="w"> </span><span class="n">vector</span><span class="o">&lt;</span><span class="kt">int</span><span class="o">&gt;</span><span class="w"> </span><span class="n">res</span><span class="p">(</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-21-101" name="__codelineno-21-101" href="#__codelineno-21-101"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-21-102" name="__codelineno-21-102" href="#__codelineno-21-102"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)];</span>
<a id="__codelineno-21-103" name="__codelineno-21-103" href="#__codelineno-21-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-104" name="__codelineno-21-104" href="#__codelineno-21-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-21-105" name="__codelineno-21-105" href="#__codelineno-21-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-21-106" name="__codelineno-21-106" href="#__codelineno-21-106"></a><span class="p">};</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.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">ArrayDeque</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;基于环形数组实现的双向队列&quot;&quot;&quot;</span>
<a id="__codelineno-22-3" name="__codelineno-22-3" href="#__codelineno-22-3"></a>
<a id="__codelineno-22-4" name="__codelineno-22-4" href="#__codelineno-22-4"></a> <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">capacity</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-22-5" name="__codelineno-22-5" href="#__codelineno-22-5"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;构造方法&quot;&quot;&quot;</span>
<a id="__codelineno-22-6" name="__codelineno-22-6" href="#__codelineno-22-6"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]</span> <span class="o">=</span> <span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">*</span> <span class="n">capacity</span>
<a id="__codelineno-22-7" name="__codelineno-22-7" href="#__codelineno-22-7"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__front</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-22-8" name="__codelineno-22-8" href="#__codelineno-22-8"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span><span class="p">:</span> <span class="nb">int</span> <span class="o">=</span> <span class="mi">0</span>
<a id="__codelineno-22-9" name="__codelineno-22-9" href="#__codelineno-22-9"></a>
<a id="__codelineno-22-10" name="__codelineno-22-10" href="#__codelineno-22-10"></a> <span class="k">def</span> <span class="nf">capacity</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-11" name="__codelineno-22-11" href="#__codelineno-22-11"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的容量&quot;&quot;&quot;</span>
<a id="__codelineno-22-12" name="__codelineno-22-12" href="#__codelineno-22-12"></a> <span class="k">return</span> <span class="nb">len</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">)</span>
<a id="__codelineno-22-13" name="__codelineno-22-13" href="#__codelineno-22-13"></a>
<a id="__codelineno-22-14" name="__codelineno-22-14" href="#__codelineno-22-14"></a> <span class="k">def</span> <span class="nf">size</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-15" name="__codelineno-22-15" href="#__codelineno-22-15"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;获取双向队列的长度&quot;&quot;&quot;</span>
<a id="__codelineno-22-16" name="__codelineno-22-16" href="#__codelineno-22-16"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span>
<a id="__codelineno-22-17" name="__codelineno-22-17" href="#__codelineno-22-17"></a>
<a id="__codelineno-22-18" name="__codelineno-22-18" href="#__codelineno-22-18"></a> <span class="k">def</span> <span class="nf">is_empty</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">bool</span><span class="p">:</span>
<a id="__codelineno-22-19" name="__codelineno-22-19" href="#__codelineno-22-19"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;判断双向队列是否为空&quot;&quot;&quot;</span>
<a id="__codelineno-22-20" name="__codelineno-22-20" href="#__codelineno-22-20"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">==</span> <span class="mi">0</span>
<a id="__codelineno-22-21" name="__codelineno-22-21" href="#__codelineno-22-21"></a>
<a id="__codelineno-22-22" name="__codelineno-22-22" href="#__codelineno-22-22"></a> <span class="k">def</span> <span class="nf">index</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">i</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-23" name="__codelineno-22-23" href="#__codelineno-22-23"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;计算环形数组索引&quot;&quot;&quot;</span>
<a id="__codelineno-22-24" name="__codelineno-22-24" href="#__codelineno-22-24"></a> <span class="c1"># 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-22-25" name="__codelineno-22-25" href="#__codelineno-22-25"></a> <span class="c1"># 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-22-26" name="__codelineno-22-26" href="#__codelineno-22-26"></a> <span class="c1"># 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-22-27" name="__codelineno-22-27" href="#__codelineno-22-27"></a> <span class="k">return</span> <span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">())</span> <span class="o">%</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">()</span>
<a id="__codelineno-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">push_first</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</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;队首入队&quot;&quot;&quot;</span>
<a id="__codelineno-22-31" name="__codelineno-22-31" href="#__codelineno-22-31"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">==</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">():</span>
<a id="__codelineno-22-32" name="__codelineno-22-32" href="#__codelineno-22-32"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-22-33" name="__codelineno-22-33" href="#__codelineno-22-33"></a> <span class="k">return</span>
<a id="__codelineno-22-34" name="__codelineno-22-34" href="#__codelineno-22-34"></a> <span class="c1"># 队首指针向左移动一位</span>
<a id="__codelineno-22-35" name="__codelineno-22-35" href="#__codelineno-22-35"></a> <span class="c1"># 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-22-36" name="__codelineno-22-36" href="#__codelineno-22-36"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-22-37" name="__codelineno-22-37" href="#__codelineno-22-37"></a> <span class="c1"># 将 num 添加至队首</span>
<a id="__codelineno-22-38" name="__codelineno-22-38" href="#__codelineno-22-38"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span><span class="p">]</span> <span class="o">=</span> <span class="n">num</span>
<a id="__codelineno-22-39" name="__codelineno-22-39" href="#__codelineno-22-39"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-22-40" name="__codelineno-22-40" href="#__codelineno-22-40"></a>
<a id="__codelineno-22-41" name="__codelineno-22-41" href="#__codelineno-22-41"></a> <span class="k">def</span> <span class="nf">push_last</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">num</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="kc">None</span><span class="p">:</span>
<a id="__codelineno-22-42" name="__codelineno-22-42" href="#__codelineno-22-42"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾入队&quot;&quot;&quot;</span>
<a id="__codelineno-22-43" name="__codelineno-22-43" href="#__codelineno-22-43"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">==</span> <span class="bp">self</span><span class="o">.</span><span class="n">capacity</span><span class="p">():</span>
<a id="__codelineno-22-44" name="__codelineno-22-44" href="#__codelineno-22-44"></a> <span class="nb">print</span><span class="p">(</span><span class="s2">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-22-45" name="__codelineno-22-45" href="#__codelineno-22-45"></a> <span class="k">return</span>
<a id="__codelineno-22-46" name="__codelineno-22-46" href="#__codelineno-22-46"></a> <span class="c1"># 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-22-47" name="__codelineno-22-47" href="#__codelineno-22-47"></a> <span class="n">rear</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span><span class="p">)</span>
<a id="__codelineno-22-48" name="__codelineno-22-48" href="#__codelineno-22-48"></a> <span class="c1"># 将 num 添加至队尾</span>
<a id="__codelineno-22-49" name="__codelineno-22-49" href="#__codelineno-22-49"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span> <span class="o">=</span> <span class="n">num</span>
<a id="__codelineno-22-50" name="__codelineno-22-50" href="#__codelineno-22-50"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-22-51" name="__codelineno-22-51" href="#__codelineno-22-51"></a>
<a id="__codelineno-22-52" name="__codelineno-22-52" href="#__codelineno-22-52"></a> <span class="k">def</span> <span class="nf">pop_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-53" name="__codelineno-22-53" href="#__codelineno-22-53"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队首出队&quot;&quot;&quot;</span>
<a id="__codelineno-22-54" name="__codelineno-22-54" href="#__codelineno-22-54"></a> <span class="n">num</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">peek_first</span><span class="p">()</span>
<a id="__codelineno-22-55" name="__codelineno-22-55" href="#__codelineno-22-55"></a> <span class="c1"># 队首指针向后移动一位</span>
<a id="__codelineno-22-56" name="__codelineno-22-56" href="#__codelineno-22-56"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-22-57" name="__codelineno-22-57" href="#__codelineno-22-57"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-22-58" name="__codelineno-22-58" href="#__codelineno-22-58"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-22-59" name="__codelineno-22-59" href="#__codelineno-22-59"></a>
<a id="__codelineno-22-60" name="__codelineno-22-60" href="#__codelineno-22-60"></a> <span class="k">def</span> <span class="nf">pop_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-61" name="__codelineno-22-61" href="#__codelineno-22-61"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;队尾出队&quot;&quot;&quot;</span>
<a id="__codelineno-22-62" name="__codelineno-22-62" href="#__codelineno-22-62"></a> <span class="n">num</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">peek_last</span><span class="p">()</span>
<a id="__codelineno-22-63" name="__codelineno-22-63" href="#__codelineno-22-63"></a> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-22-64" name="__codelineno-22-64" href="#__codelineno-22-64"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-22-65" name="__codelineno-22-65" href="#__codelineno-22-65"></a>
<a id="__codelineno-22-66" name="__codelineno-22-66" href="#__codelineno-22-66"></a> <span class="k">def</span> <span class="nf">peek_first</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-67" name="__codelineno-22-67" href="#__codelineno-22-67"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队首元素&quot;&quot;&quot;</span>
<a id="__codelineno-22-68" name="__codelineno-22-68" href="#__codelineno-22-68"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-22-69" name="__codelineno-22-69" href="#__codelineno-22-69"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-22-70" name="__codelineno-22-70" href="#__codelineno-22-70"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span><span class="p">]</span>
<a id="__codelineno-22-71" name="__codelineno-22-71" href="#__codelineno-22-71"></a>
<a id="__codelineno-22-72" name="__codelineno-22-72" href="#__codelineno-22-72"></a> <span class="k">def</span> <span class="nf">peek_last</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">int</span><span class="p">:</span>
<a id="__codelineno-22-73" name="__codelineno-22-73" href="#__codelineno-22-73"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;访问队尾元素&quot;&quot;&quot;</span>
<a id="__codelineno-22-74" name="__codelineno-22-74" href="#__codelineno-22-74"></a> <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">is_empty</span><span class="p">():</span>
<a id="__codelineno-22-75" name="__codelineno-22-75" href="#__codelineno-22-75"></a> <span class="k">raise</span> <span class="ne">IndexError</span><span class="p">(</span><span class="s2">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-22-76" name="__codelineno-22-76" href="#__codelineno-22-76"></a> <span class="c1"># 计算尾元素索引</span>
<a id="__codelineno-22-77" name="__codelineno-22-77" href="#__codelineno-22-77"></a> <span class="n">last</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">+</span> <span class="bp">self</span><span class="o">.</span><span class="n">__size</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-22-78" name="__codelineno-22-78" href="#__codelineno-22-78"></a> <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">[</span><span class="n">last</span><span class="p">]</span>
<a id="__codelineno-22-79" name="__codelineno-22-79" href="#__codelineno-22-79"></a>
<a id="__codelineno-22-80" name="__codelineno-22-80" href="#__codelineno-22-80"></a> <span class="k">def</span> <span class="nf">to_array</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span> <span class="o">-&gt;</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">]:</span>
<a id="__codelineno-22-81" name="__codelineno-22-81" href="#__codelineno-22-81"></a><span class="w"> </span><span class="sd">&quot;&quot;&quot;返回数组用于打印&quot;&quot;&quot;</span>
<a id="__codelineno-22-82" name="__codelineno-22-82" href="#__codelineno-22-82"></a> <span class="c1"># 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-22-83" name="__codelineno-22-83" href="#__codelineno-22-83"></a> <span class="n">res</span> <span class="o">=</span> <span class="p">[]</span>
<a id="__codelineno-22-84" name="__codelineno-22-84" href="#__codelineno-22-84"></a> <span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__size</span><span class="p">):</span>
<a id="__codelineno-22-85" name="__codelineno-22-85" href="#__codelineno-22-85"></a> <span class="n">res</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__nums</span><span class="p">[</span><span class="bp">self</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">__front</span> <span class="o">+</span> <span class="n">i</span><span class="p">)])</span>
<a id="__codelineno-22-86" name="__codelineno-22-86" href="#__codelineno-22-86"></a> <span class="k">return</span> <span class="n">res</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.go</span><pre><span></span><code><a id="__codelineno-23-1" name="__codelineno-23-1" href="#__codelineno-23-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</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">arrayDeque</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">nums</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-23-4" name="__codelineno-23-4" href="#__codelineno-23-4"></a><span class="w"> </span><span class="nx">front</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-23-5" name="__codelineno-23-5" href="#__codelineno-23-5"></a><span class="w"> </span><span class="nx">queSize</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-23-6" name="__codelineno-23-6" href="#__codelineno-23-6"></a><span class="w"> </span><span class="nx">queCapacity</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="c1">// 队列容量（即最大容纳元素数量）</span>
<a id="__codelineno-23-7" name="__codelineno-23-7" href="#__codelineno-23-7"></a><span class="p">}</span>
<a id="__codelineno-23-8" name="__codelineno-23-8" href="#__codelineno-23-8"></a>
<a id="__codelineno-23-9" name="__codelineno-23-9" href="#__codelineno-23-9"></a><span class="cm">/* 初始化队列 */</span>
<a id="__codelineno-23-10" name="__codelineno-23-10" href="#__codelineno-23-10"></a><span class="kd">func</span><span class="w"> </span><span class="nx">newArrayDeque</span><span class="p">(</span><span class="nx">queCapacity</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-11" name="__codelineno-23-11" href="#__codelineno-23-11"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">&amp;</span><span class="nx">arrayDeque</span><span class="p">{</span>
<a id="__codelineno-23-12" name="__codelineno-23-12" href="#__codelineno-23-12"></a><span class="w"> </span><span class="nx">nums</span><span class="p">:</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">queCapacity</span><span class="p">),</span>
<a id="__codelineno-23-13" name="__codelineno-23-13" href="#__codelineno-23-13"></a><span class="w"> </span><span class="nx">queCapacity</span><span class="p">:</span><span class="w"> </span><span class="nx">queCapacity</span><span class="p">,</span>
<a id="__codelineno-23-14" name="__codelineno-23-14" href="#__codelineno-23-14"></a><span class="w"> </span><span class="nx">front</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-23-15" name="__codelineno-23-15" href="#__codelineno-23-15"></a><span class="w"> </span><span class="nx">queSize</span><span class="p">:</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span>
<a id="__codelineno-23-16" name="__codelineno-23-16" href="#__codelineno-23-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-17" name="__codelineno-23-17" href="#__codelineno-23-17"></a><span class="p">}</span>
<a id="__codelineno-23-18" name="__codelineno-23-18" href="#__codelineno-23-18"></a>
<a id="__codelineno-23-19" name="__codelineno-23-19" href="#__codelineno-23-19"></a><span class="cm">/* 获取双向队列的长度 */</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">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">q</span><span class="p">.</span><span class="nx">queSize</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">/* 判断双向队列是否为空 */</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">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-26" name="__codelineno-23-26" href="#__codelineno-23-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span>
<a id="__codelineno-23-27" name="__codelineno-23-27" href="#__codelineno-23-27"></a><span class="p">}</span>
<a id="__codelineno-23-28" name="__codelineno-23-28" href="#__codelineno-23-28"></a>
<a id="__codelineno-23-29" name="__codelineno-23-29" href="#__codelineno-23-29"></a><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-23-30" name="__codelineno-23-30" href="#__codelineno-23-30"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-31" name="__codelineno-23-31" href="#__codelineno-23-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-23-32" name="__codelineno-23-32" href="#__codelineno-23-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-23-33" name="__codelineno-23-33" href="#__codelineno-23-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-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="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="p">)</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span>
<a id="__codelineno-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">/* 队首入队 */</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">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-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">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-40" name="__codelineno-23-40" href="#__codelineno-23-40"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-23-41" name="__codelineno-23-41" href="#__codelineno-23-41"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-23-42" name="__codelineno-23-42" href="#__codelineno-23-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-43" name="__codelineno-23-43" href="#__codelineno-23-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-23-44" name="__codelineno-23-44" href="#__codelineno-23-44"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-23-45" name="__codelineno-23-45" href="#__codelineno-23-45"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-23-46" name="__codelineno-23-46" href="#__codelineno-23-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-23-47" name="__codelineno-23-47" href="#__codelineno-23-47"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-23-48" name="__codelineno-23-48" href="#__codelineno-23-48"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span>
<a id="__codelineno-23-49" name="__codelineno-23-49" href="#__codelineno-23-49"></a><span class="p">}</span>
<a id="__codelineno-23-50" name="__codelineno-23-50" href="#__codelineno-23-50"></a>
<a id="__codelineno-23-51" name="__codelineno-23-51" href="#__codelineno-23-51"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-23-52" name="__codelineno-23-52" href="#__codelineno-23-52"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="w"> </span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-53" name="__codelineno-23-53" href="#__codelineno-23-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queCapacity</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-54" name="__codelineno-23-54" href="#__codelineno-23-54"></a><span class="w"> </span><span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-23-55" name="__codelineno-23-55" href="#__codelineno-23-55"></a><span class="w"> </span><span class="k">return</span>
<a id="__codelineno-23-56" name="__codelineno-23-56" href="#__codelineno-23-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-57" name="__codelineno-23-57" href="#__codelineno-23-57"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-23-58" name="__codelineno-23-58" href="#__codelineno-23-58"></a><span class="w"> </span><span class="nx">rear</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">)</span>
<a id="__codelineno-23-59" name="__codelineno-23-59" href="#__codelineno-23-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-23-60" name="__codelineno-23-60" href="#__codelineno-23-60"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-23-61" name="__codelineno-23-61" href="#__codelineno-23-61"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span>
<a id="__codelineno-23-62" name="__codelineno-23-62" href="#__codelineno-23-62"></a><span class="p">}</span>
<a id="__codelineno-23-63" name="__codelineno-23-63" href="#__codelineno-23-63"></a>
<a id="__codelineno-23-64" name="__codelineno-23-64" href="#__codelineno-23-64"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-23-65" name="__codelineno-23-65" href="#__codelineno-23-65"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-66" name="__codelineno-23-66" href="#__codelineno-23-66"></a><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">()</span>
<a id="__codelineno-23-67" name="__codelineno-23-67" href="#__codelineno-23-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-23-68" name="__codelineno-23-68" href="#__codelineno-23-68"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-23-69" name="__codelineno-23-69" href="#__codelineno-23-69"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span>
<a id="__codelineno-23-70" name="__codelineno-23-70" href="#__codelineno-23-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-23-71" name="__codelineno-23-71" href="#__codelineno-23-71"></a><span class="p">}</span>
<a id="__codelineno-23-72" name="__codelineno-23-72" href="#__codelineno-23-72"></a>
<a id="__codelineno-23-73" name="__codelineno-23-73" href="#__codelineno-23-73"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-23-74" name="__codelineno-23-74" href="#__codelineno-23-74"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-75" name="__codelineno-23-75" href="#__codelineno-23-75"></a><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">()</span>
<a id="__codelineno-23-76" name="__codelineno-23-76" href="#__codelineno-23-76"></a><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span>
<a id="__codelineno-23-77" name="__codelineno-23-77" href="#__codelineno-23-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span>
<a id="__codelineno-23-78" name="__codelineno-23-78" href="#__codelineno-23-78"></a><span class="p">}</span>
<a id="__codelineno-23-79" name="__codelineno-23-79" href="#__codelineno-23-79"></a>
<a id="__codelineno-23-80" name="__codelineno-23-80" href="#__codelineno-23-80"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-23-81" name="__codelineno-23-81" href="#__codelineno-23-81"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-82" name="__codelineno-23-82" href="#__codelineno-23-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-83" name="__codelineno-23-83" href="#__codelineno-23-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-23-84" name="__codelineno-23-84" href="#__codelineno-23-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-85" name="__codelineno-23-85" href="#__codelineno-23-85"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span>
<a id="__codelineno-23-86" name="__codelineno-23-86" href="#__codelineno-23-86"></a><span class="p">}</span>
<a id="__codelineno-23-87" name="__codelineno-23-87" href="#__codelineno-23-87"></a>
<a id="__codelineno-23-88" name="__codelineno-23-88" href="#__codelineno-23-88"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-23-89" name="__codelineno-23-89" href="#__codelineno-23-89"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="kt">any</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-90" name="__codelineno-23-90" href="#__codelineno-23-90"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-91" name="__codelineno-23-91" href="#__codelineno-23-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="kc">nil</span>
<a id="__codelineno-23-92" name="__codelineno-23-92" href="#__codelineno-23-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-93" name="__codelineno-23-93" href="#__codelineno-23-93"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-23-94" name="__codelineno-23-94" href="#__codelineno-23-94"></a><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-23-95" name="__codelineno-23-95" href="#__codelineno-23-95"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">]</span>
<a id="__codelineno-23-96" name="__codelineno-23-96" href="#__codelineno-23-96"></a><span class="p">}</span>
<a id="__codelineno-23-97" name="__codelineno-23-97" href="#__codelineno-23-97"></a>
<a id="__codelineno-23-98" name="__codelineno-23-98" href="#__codelineno-23-98"></a><span class="cm">/* 获取 Slice 用于打印 */</span>
<a id="__codelineno-23-99" name="__codelineno-23-99" href="#__codelineno-23-99"></a><span class="kd">func</span><span class="w"> </span><span class="p">(</span><span class="nx">q</span><span class="w"> </span><span class="o">*</span><span class="nx">arrayDeque</span><span class="p">)</span><span class="w"> </span><span class="nx">toSlice</span><span class="p">()</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-100" name="__codelineno-23-100" href="#__codelineno-23-100"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-23-101" name="__codelineno-23-101" href="#__codelineno-23-101"></a><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">)</span>
<a id="__codelineno-23-102" name="__codelineno-23-102" href="#__codelineno-23-102"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="p">&lt;</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-23-103" name="__codelineno-23-103" href="#__codelineno-23-103"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">q</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">q</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)]</span>
<a id="__codelineno-23-104" name="__codelineno-23-104" href="#__codelineno-23-104"></a><span class="w"> </span><span class="nx">j</span><span class="o">++</span>
<a id="__codelineno-23-105" name="__codelineno-23-105" href="#__codelineno-23-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-23-106" name="__codelineno-23-106" href="#__codelineno-23-106"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span>
<a id="__codelineno-23-107" name="__codelineno-23-107" href="#__codelineno-23-107"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.js</span><pre><span></span><code><a id="__codelineno-24-1" name="__codelineno-24-1" href="#__codelineno-24-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</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">ArrayDeque</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">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-24-4" name="__codelineno-24-4" href="#__codelineno-24-4"></a><span class="w"> </span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-24-5" name="__codelineno-24-5" href="#__codelineno-24-5"></a><span class="w"> </span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-24-6" name="__codelineno-24-6" href="#__codelineno-24-6"></a>
<a id="__codelineno-24-7" name="__codelineno-24-7" href="#__codelineno-24-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-24-8" name="__codelineno-24-8" href="#__codelineno-24-8"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-9" name="__codelineno-24-9" href="#__codelineno-24-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">capacity</span><span class="p">);</span>
<a id="__codelineno-24-10" name="__codelineno-24-10" href="#__codelineno-24-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-24-11" name="__codelineno-24-11" href="#__codelineno-24-11"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-24-12" name="__codelineno-24-12" href="#__codelineno-24-12"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-13" name="__codelineno-24-13" href="#__codelineno-24-13"></a>
<a id="__codelineno-24-14" name="__codelineno-24-14" href="#__codelineno-24-14"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-24-15" name="__codelineno-24-15" href="#__codelineno-24-15"></a><span class="w"> </span><span class="nx">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-16" name="__codelineno-24-16" href="#__codelineno-24-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-24-17" name="__codelineno-24-17" href="#__codelineno-24-17"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-18" name="__codelineno-24-18" href="#__codelineno-24-18"></a>
<a id="__codelineno-24-19" name="__codelineno-24-19" href="#__codelineno-24-19"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-24-20" name="__codelineno-24-20" href="#__codelineno-24-20"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-21" name="__codelineno-24-21" href="#__codelineno-24-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-24-22" name="__codelineno-24-22" href="#__codelineno-24-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-23" name="__codelineno-24-23" href="#__codelineno-24-23"></a>
<a id="__codelineno-24-24" name="__codelineno-24-24" href="#__codelineno-24-24"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-24-25" name="__codelineno-24-25" href="#__codelineno-24-25"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-26" name="__codelineno-24-26" href="#__codelineno-24-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-24-27" name="__codelineno-24-27" href="#__codelineno-24-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-28" name="__codelineno-24-28" href="#__codelineno-24-28"></a>
<a id="__codelineno-24-29" name="__codelineno-24-29" href="#__codelineno-24-29"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-24-30" name="__codelineno-24-30" href="#__codelineno-24-30"></a><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-31" name="__codelineno-24-31" href="#__codelineno-24-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-24-32" name="__codelineno-24-32" href="#__codelineno-24-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-24-33" name="__codelineno-24-33" href="#__codelineno-24-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-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="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">();</span>
<a id="__codelineno-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">/* 队首入队 */</span>
<a id="__codelineno-24-38" name="__codelineno-24-38" href="#__codelineno-24-38"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-39" name="__codelineno-24-39" href="#__codelineno-24-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-40" name="__codelineno-24-40" href="#__codelineno-24-40"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-24-41" name="__codelineno-24-41" href="#__codelineno-24-41"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-24-42" name="__codelineno-24-42" href="#__codelineno-24-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-43" name="__codelineno-24-43" href="#__codelineno-24-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-24-44" name="__codelineno-24-44" href="#__codelineno-24-44"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-24-45" name="__codelineno-24-45" href="#__codelineno-24-45"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-24-46" name="__codelineno-24-46" href="#__codelineno-24-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-24-47" name="__codelineno-24-47" href="#__codelineno-24-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-24-48" name="__codelineno-24-48" href="#__codelineno-24-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-24-49" name="__codelineno-24-49" href="#__codelineno-24-49"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-50" name="__codelineno-24-50" href="#__codelineno-24-50"></a>
<a id="__codelineno-24-51" name="__codelineno-24-51" href="#__codelineno-24-51"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-24-52" name="__codelineno-24-52" href="#__codelineno-24-52"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-53" name="__codelineno-24-53" href="#__codelineno-24-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-54" name="__codelineno-24-54" href="#__codelineno-24-54"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-24-55" name="__codelineno-24-55" href="#__codelineno-24-55"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-24-56" name="__codelineno-24-56" href="#__codelineno-24-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-57" name="__codelineno-24-57" href="#__codelineno-24-57"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-24-58" name="__codelineno-24-58" href="#__codelineno-24-58"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">);</span>
<a id="__codelineno-24-59" name="__codelineno-24-59" href="#__codelineno-24-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-24-60" name="__codelineno-24-60" href="#__codelineno-24-60"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-24-61" name="__codelineno-24-61" href="#__codelineno-24-61"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-24-62" name="__codelineno-24-62" href="#__codelineno-24-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-63" name="__codelineno-24-63" href="#__codelineno-24-63"></a>
<a id="__codelineno-24-64" name="__codelineno-24-64" href="#__codelineno-24-64"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-24-65" name="__codelineno-24-65" href="#__codelineno-24-65"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-66" name="__codelineno-24-66" href="#__codelineno-24-66"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">();</span>
<a id="__codelineno-24-67" name="__codelineno-24-67" href="#__codelineno-24-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-24-68" name="__codelineno-24-68" href="#__codelineno-24-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-24-69" name="__codelineno-24-69" href="#__codelineno-24-69"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-24-70" name="__codelineno-24-70" href="#__codelineno-24-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-24-71" name="__codelineno-24-71" href="#__codelineno-24-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-72" name="__codelineno-24-72" href="#__codelineno-24-72"></a>
<a id="__codelineno-24-73" name="__codelineno-24-73" href="#__codelineno-24-73"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-24-74" name="__codelineno-24-74" href="#__codelineno-24-74"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-75" name="__codelineno-24-75" href="#__codelineno-24-75"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">();</span>
<a id="__codelineno-24-76" name="__codelineno-24-76" href="#__codelineno-24-76"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-24-77" name="__codelineno-24-77" href="#__codelineno-24-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-24-78" name="__codelineno-24-78" href="#__codelineno-24-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-79" name="__codelineno-24-79" href="#__codelineno-24-79"></a>
<a id="__codelineno-24-80" name="__codelineno-24-80" href="#__codelineno-24-80"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-24-81" name="__codelineno-24-81" href="#__codelineno-24-81"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-82" name="__codelineno-24-82" href="#__codelineno-24-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-24-83" name="__codelineno-24-83" href="#__codelineno-24-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">];</span>
<a id="__codelineno-24-84" name="__codelineno-24-84" href="#__codelineno-24-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-85" name="__codelineno-24-85" href="#__codelineno-24-85"></a>
<a id="__codelineno-24-86" name="__codelineno-24-86" href="#__codelineno-24-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-24-87" name="__codelineno-24-87" href="#__codelineno-24-87"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-88" name="__codelineno-24-88" href="#__codelineno-24-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-24-89" name="__codelineno-24-89" href="#__codelineno-24-89"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-24-90" name="__codelineno-24-90" href="#__codelineno-24-90"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-24-91" name="__codelineno-24-91" href="#__codelineno-24-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">];</span>
<a id="__codelineno-24-92" name="__codelineno-24-92" href="#__codelineno-24-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-93" name="__codelineno-24-93" href="#__codelineno-24-93"></a>
<a id="__codelineno-24-94" name="__codelineno-24-94" href="#__codelineno-24-94"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-24-95" name="__codelineno-24-95" href="#__codelineno-24-95"></a><span class="w"> </span><span class="nx">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-96" name="__codelineno-24-96" href="#__codelineno-24-96"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-24-97" name="__codelineno-24-97" href="#__codelineno-24-97"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-24-98" name="__codelineno-24-98" href="#__codelineno-24-98"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-24-99" name="__codelineno-24-99" href="#__codelineno-24-99"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="err">#</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)];</span>
<a id="__codelineno-24-100" name="__codelineno-24-100" href="#__codelineno-24-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-101" name="__codelineno-24-101" href="#__codelineno-24-101"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</span>
<a id="__codelineno-24-102" name="__codelineno-24-102" href="#__codelineno-24-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-24-103" name="__codelineno-24-103" href="#__codelineno-24-103"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.ts</span><pre><span></span><code><a id="__codelineno-25-1" name="__codelineno-25-1" href="#__codelineno-25-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-25-2" name="__codelineno-25-2" href="#__codelineno-25-2"></a><span class="kd">class</span><span class="w"> </span><span class="nx">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-3" name="__codelineno-25-3" href="#__codelineno-25-3"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">nums</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[];</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-25-4" name="__codelineno-25-4" href="#__codelineno-25-4"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">front</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-25-5" name="__codelineno-25-5" href="#__codelineno-25-5"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="nx">queSize</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-25-6" name="__codelineno-25-6" href="#__codelineno-25-6"></a>
<a id="__codelineno-25-7" name="__codelineno-25-7" href="#__codelineno-25-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-25-8" name="__codelineno-25-8" href="#__codelineno-25-8"></a><span class="w"> </span><span class="kr">constructor</span><span class="p">(</span><span class="nx">capacity</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-9" name="__codelineno-25-9" href="#__codelineno-25-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="nb">Array</span><span class="p">(</span><span class="nx">capacity</span><span class="p">);</span>
<a id="__codelineno-25-10" name="__codelineno-25-10" href="#__codelineno-25-10"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-25-11" name="__codelineno-25-11" href="#__codelineno-25-11"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-25-12" name="__codelineno-25-12" href="#__codelineno-25-12"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-13" name="__codelineno-25-13" href="#__codelineno-25-13"></a>
<a id="__codelineno-25-14" name="__codelineno-25-14" href="#__codelineno-25-14"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-25-15" name="__codelineno-25-15" href="#__codelineno-25-15"></a><span class="w"> </span><span class="nx">capacity</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-16" name="__codelineno-25-16" href="#__codelineno-25-16"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<a id="__codelineno-25-17" name="__codelineno-25-17" href="#__codelineno-25-17"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-18" name="__codelineno-25-18" href="#__codelineno-25-18"></a>
<a id="__codelineno-25-19" name="__codelineno-25-19" href="#__codelineno-25-19"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-25-20" name="__codelineno-25-20" href="#__codelineno-25-20"></a><span class="w"> </span><span class="nx">size</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-21" name="__codelineno-25-21" href="#__codelineno-25-21"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span>
<a id="__codelineno-25-22" name="__codelineno-25-22" href="#__codelineno-25-22"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-23" name="__codelineno-25-23" href="#__codelineno-25-23"></a>
<a id="__codelineno-25-24" name="__codelineno-25-24" href="#__codelineno-25-24"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-25-25" name="__codelineno-25-25" href="#__codelineno-25-25"></a><span class="w"> </span><span class="nx">isEmpty</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">boolean</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-26" name="__codelineno-25-26" href="#__codelineno-25-26"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="mf">0</span><span class="p">;</span>
<a id="__codelineno-25-27" name="__codelineno-25-27" href="#__codelineno-25-27"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-28" name="__codelineno-25-28" href="#__codelineno-25-28"></a>
<a id="__codelineno-25-29" name="__codelineno-25-29" href="#__codelineno-25-29"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-25-30" name="__codelineno-25-30" href="#__codelineno-25-30"></a><span class="w"> </span><span class="nx">index</span><span class="p">(</span><span class="nx">i</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-31" name="__codelineno-25-31" href="#__codelineno-25-31"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-25-32" name="__codelineno-25-32" href="#__codelineno-25-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-25-33" name="__codelineno-25-33" href="#__codelineno-25-33"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-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="p">(</span><span class="nx">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">();</span>
<a id="__codelineno-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">/* 队首入队 */</span>
<a id="__codelineno-25-38" name="__codelineno-25-38" href="#__codelineno-25-38"></a><span class="w"> </span><span class="nx">pushFirst</span><span class="p">(</span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-39" name="__codelineno-25-39" href="#__codelineno-25-39"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-40" name="__codelineno-25-40" href="#__codelineno-25-40"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-25-41" name="__codelineno-25-41" href="#__codelineno-25-41"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-25-42" name="__codelineno-25-42" href="#__codelineno-25-42"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-43" name="__codelineno-25-43" href="#__codelineno-25-43"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-25-44" name="__codelineno-25-44" href="#__codelineno-25-44"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-25-45" name="__codelineno-25-45" href="#__codelineno-25-45"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-25-46" name="__codelineno-25-46" href="#__codelineno-25-46"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-25-47" name="__codelineno-25-47" href="#__codelineno-25-47"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-25-48" name="__codelineno-25-48" href="#__codelineno-25-48"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-25-49" name="__codelineno-25-49" href="#__codelineno-25-49"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-50" name="__codelineno-25-50" href="#__codelineno-25-50"></a>
<a id="__codelineno-25-51" name="__codelineno-25-51" href="#__codelineno-25-51"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-25-52" name="__codelineno-25-52" href="#__codelineno-25-52"></a><span class="w"> </span><span class="nx">pushLast</span><span class="p">(</span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">)</span><span class="o">:</span><span class="w"> </span><span class="ow">void</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-53" name="__codelineno-25-53" href="#__codelineno-25-53"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">===</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-54" name="__codelineno-25-54" href="#__codelineno-25-54"></a><span class="w"> </span><span class="nx">console</span><span class="p">.</span><span class="nx">log</span><span class="p">(</span><span class="s1">&#39;双向队列已满&#39;</span><span class="p">);</span>
<a id="__codelineno-25-55" name="__codelineno-25-55" href="#__codelineno-25-55"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-25-56" name="__codelineno-25-56" href="#__codelineno-25-56"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-57" name="__codelineno-25-57" href="#__codelineno-25-57"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-25-58" name="__codelineno-25-58" href="#__codelineno-25-58"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">rear</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">);</span>
<a id="__codelineno-25-59" name="__codelineno-25-59" href="#__codelineno-25-59"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-25-60" name="__codelineno-25-60" href="#__codelineno-25-60"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-25-61" name="__codelineno-25-61" href="#__codelineno-25-61"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-25-62" name="__codelineno-25-62" href="#__codelineno-25-62"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-63" name="__codelineno-25-63" href="#__codelineno-25-63"></a>
<a id="__codelineno-25-64" name="__codelineno-25-64" href="#__codelineno-25-64"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-25-65" name="__codelineno-25-65" href="#__codelineno-25-65"></a><span class="w"> </span><span class="nx">popFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-66" name="__codelineno-25-66" href="#__codelineno-25-66"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekFirst</span><span class="p">();</span>
<a id="__codelineno-25-67" name="__codelineno-25-67" href="#__codelineno-25-67"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-25-68" name="__codelineno-25-68" href="#__codelineno-25-68"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-25-69" name="__codelineno-25-69" href="#__codelineno-25-69"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-25-70" name="__codelineno-25-70" href="#__codelineno-25-70"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-25-71" name="__codelineno-25-71" href="#__codelineno-25-71"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-72" name="__codelineno-25-72" href="#__codelineno-25-72"></a>
<a id="__codelineno-25-73" name="__codelineno-25-73" href="#__codelineno-25-73"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-25-74" name="__codelineno-25-74" href="#__codelineno-25-74"></a><span class="w"> </span><span class="nx">popLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-75" name="__codelineno-25-75" href="#__codelineno-25-75"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">num</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">peekLast</span><span class="p">();</span>
<a id="__codelineno-25-76" name="__codelineno-25-76" href="#__codelineno-25-76"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-25-77" name="__codelineno-25-77" href="#__codelineno-25-77"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">num</span><span class="p">;</span>
<a id="__codelineno-25-78" name="__codelineno-25-78" href="#__codelineno-25-78"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-79" name="__codelineno-25-79" href="#__codelineno-25-79"></a>
<a id="__codelineno-25-80" name="__codelineno-25-80" href="#__codelineno-25-80"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-25-81" name="__codelineno-25-81" href="#__codelineno-25-81"></a><span class="w"> </span><span class="nx">peekFirst</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-82" name="__codelineno-25-82" href="#__codelineno-25-82"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-25-83" name="__codelineno-25-83" href="#__codelineno-25-83"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">];</span>
<a id="__codelineno-25-84" name="__codelineno-25-84" href="#__codelineno-25-84"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-85" name="__codelineno-25-85" href="#__codelineno-25-85"></a>
<a id="__codelineno-25-86" name="__codelineno-25-86" href="#__codelineno-25-86"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-25-87" name="__codelineno-25-87" href="#__codelineno-25-87"></a><span class="w"> </span><span class="nx">peekLast</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-88" name="__codelineno-25-88" href="#__codelineno-25-88"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="ow">new</span><span class="w"> </span><span class="ne">Error</span><span class="p">(</span><span class="s1">&#39;The Deque Is Empty.&#39;</span><span class="p">);</span>
<a id="__codelineno-25-89" name="__codelineno-25-89" href="#__codelineno-25-89"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-25-90" name="__codelineno-25-90" href="#__codelineno-25-90"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mf">1</span><span class="p">);</span>
<a id="__codelineno-25-91" name="__codelineno-25-91" href="#__codelineno-25-91"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="nx">last</span><span class="p">];</span>
<a id="__codelineno-25-92" name="__codelineno-25-92" href="#__codelineno-25-92"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-93" name="__codelineno-25-93" href="#__codelineno-25-93"></a>
<a id="__codelineno-25-94" name="__codelineno-25-94" href="#__codelineno-25-94"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-25-95" name="__codelineno-25-95" href="#__codelineno-25-95"></a><span class="w"> </span><span class="nx">toArray</span><span class="p">()</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-96" name="__codelineno-25-96" href="#__codelineno-25-96"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-25-97" name="__codelineno-25-97" href="#__codelineno-25-97"></a><span class="w"> </span><span class="kd">const</span><span class="w"> </span><span class="nx">res</span><span class="o">:</span><span class="w"> </span><span class="kt">number</span><span class="p">[]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[];</span>
<a id="__codelineno-25-98" name="__codelineno-25-98" href="#__codelineno-25-98"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kd">let</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mf">0</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">front</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">queSize</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="nx">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-25-99" name="__codelineno-25-99" href="#__codelineno-25-99"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="nx">nums</span><span class="p">[</span><span class="k">this</span><span class="p">.</span><span class="nx">index</span><span class="p">(</span><span class="nx">j</span><span class="p">)];</span>
<a id="__codelineno-25-100" name="__codelineno-25-100" href="#__codelineno-25-100"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-101" name="__codelineno-25-101" href="#__codelineno-25-101"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">;</span>
<a id="__codelineno-25-102" name="__codelineno-25-102" href="#__codelineno-25-102"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-25-103" name="__codelineno-25-103" href="#__codelineno-25-103"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.c</span><pre><span></span><code><a id="__codelineno-26-1" name="__codelineno-26-1" href="#__codelineno-26-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-26-2" name="__codelineno-26-2" href="#__codelineno-26-2"></a><span class="k">struct</span><span class="w"> </span><span class="nc">arrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-3" name="__codelineno-26-3" href="#__codelineno-26-3"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="o">*</span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储队列元素的数组</span>
<a id="__codelineno-26-4" name="__codelineno-26-4" href="#__codelineno-26-4"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-26-5" name="__codelineno-26-5" href="#__codelineno-26-5"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 尾指针，指向队尾 + 1</span>
<a id="__codelineno-26-6" name="__codelineno-26-6" href="#__codelineno-26-6"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queCapacity</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队列容量</span>
<a id="__codelineno-26-7" name="__codelineno-26-7" href="#__codelineno-26-7"></a><span class="p">};</span>
<a id="__codelineno-26-8" name="__codelineno-26-8" href="#__codelineno-26-8"></a>
<a id="__codelineno-26-9" name="__codelineno-26-9" href="#__codelineno-26-9"></a><span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">arrayDeque</span><span class="w"> </span><span class="n">arrayDeque</span><span class="p">;</span>
<a id="__codelineno-26-10" name="__codelineno-26-10" href="#__codelineno-26-10"></a>
<a id="__codelineno-26-11" name="__codelineno-26-11" href="#__codelineno-26-11"></a><span class="cm">/* 构造函数 */</span>
<a id="__codelineno-26-12" name="__codelineno-26-12" href="#__codelineno-26-12"></a><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="nf">newArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-13" name="__codelineno-26-13" href="#__codelineno-26-13"></a><span class="w"> </span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="n">arrayDeque</span><span class="p">));</span>
<a id="__codelineno-26-14" name="__codelineno-26-14" href="#__codelineno-26-14"></a><span class="w"> </span><span class="c1">// 初始化数组</span>
<a id="__codelineno-26-15" name="__codelineno-26-15" href="#__codelineno-26-15"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">capacity</span><span class="p">;</span>
<a id="__codelineno-26-16" name="__codelineno-26-16" href="#__codelineno-26-16"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="o">*</span><span class="p">)</span><span class="n">malloc</span><span class="p">(</span><span class="k">sizeof</span><span class="p">(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">);</span>
<a id="__codelineno-26-17" name="__codelineno-26-17" href="#__codelineno-26-17"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-18" name="__codelineno-26-18" href="#__codelineno-26-18"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="p">;</span>
<a id="__codelineno-26-19" name="__codelineno-26-19" href="#__codelineno-26-19"></a><span class="p">}</span>
<a id="__codelineno-26-20" name="__codelineno-26-20" href="#__codelineno-26-20"></a>
<a id="__codelineno-26-21" name="__codelineno-26-21" href="#__codelineno-26-21"></a><span class="cm">/* 析构函数 */</span>
<a id="__codelineno-26-22" name="__codelineno-26-22" href="#__codelineno-26-22"></a><span class="kt">void</span><span class="w"> </span><span class="nf">delArrayDeque</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-23" name="__codelineno-26-23" href="#__codelineno-26-23"></a><span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">);</span>
<a id="__codelineno-26-24" name="__codelineno-26-24" href="#__codelineno-26-24"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-25" name="__codelineno-26-25" href="#__codelineno-26-25"></a><span class="p">}</span>
<a id="__codelineno-26-26" name="__codelineno-26-26" href="#__codelineno-26-26"></a>
<a id="__codelineno-26-27" name="__codelineno-26-27" href="#__codelineno-26-27"></a><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-26-28" name="__codelineno-26-28" href="#__codelineno-26-28"></a><span class="kt">int</span><span class="w"> </span><span class="nf">capacity</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-29" name="__codelineno-26-29" href="#__codelineno-26-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">;</span>
<a id="__codelineno-26-30" name="__codelineno-26-30" href="#__codelineno-26-30"></a><span class="p">}</span>
<a id="__codelineno-26-31" name="__codelineno-26-31" href="#__codelineno-26-31"></a>
<a id="__codelineno-26-32" name="__codelineno-26-32" href="#__codelineno-26-32"></a><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-26-33" name="__codelineno-26-33" href="#__codelineno-26-33"></a><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-34" name="__codelineno-26-34" href="#__codelineno-26-34"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-26-35" name="__codelineno-26-35" href="#__codelineno-26-35"></a><span class="p">}</span>
<a id="__codelineno-26-36" name="__codelineno-26-36" href="#__codelineno-26-36"></a>
<a id="__codelineno-26-37" name="__codelineno-26-37" href="#__codelineno-26-37"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-26-38" name="__codelineno-26-38" href="#__codelineno-26-38"></a><span class="kt">bool</span><span class="w"> </span><span class="nf">empty</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-39" name="__codelineno-26-39" href="#__codelineno-26-39"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-40" name="__codelineno-26-40" href="#__codelineno-26-40"></a><span class="p">}</span>
<a id="__codelineno-26-41" name="__codelineno-26-41" href="#__codelineno-26-41"></a>
<a id="__codelineno-26-42" name="__codelineno-26-42" href="#__codelineno-26-42"></a><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-26-43" name="__codelineno-26-43" href="#__codelineno-26-43"></a><span class="kt">bool</span><span class="w"> </span><span class="nf">empty</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-44" name="__codelineno-26-44" href="#__codelineno-26-44"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<a id="__codelineno-26-45" name="__codelineno-26-45" href="#__codelineno-26-45"></a><span class="p">}</span>
<a id="__codelineno-26-46" name="__codelineno-26-46" href="#__codelineno-26-46"></a>
<a id="__codelineno-26-47" name="__codelineno-26-47" href="#__codelineno-26-47"></a><span class="kt">int</span><span class="w"> </span><span class="nf">dequeIndex</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-48" name="__codelineno-26-48" href="#__codelineno-26-48"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-26-49" name="__codelineno-26-49" href="#__codelineno-26-49"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部时，回到头部</span>
<a id="__codelineno-26-50" name="__codelineno-26-50" href="#__codelineno-26-50"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-26-51" name="__codelineno-26-51" href="#__codelineno-26-51"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">((</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">));</span>
<a id="__codelineno-26-52" name="__codelineno-26-52" href="#__codelineno-26-52"></a><span class="p">}</span>
<a id="__codelineno-26-53" name="__codelineno-26-53" href="#__codelineno-26-53"></a>
<a id="__codelineno-26-54" name="__codelineno-26-54" href="#__codelineno-26-54"></a><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-26-55" name="__codelineno-26-55" href="#__codelineno-26-55"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-56" name="__codelineno-26-56" href="#__codelineno-26-56"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-57" name="__codelineno-26-57" href="#__codelineno-26-57"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;双向队列已满</span><span class="se">\r\n</span><span class="s">&quot;</span><span class="p">);</span>
<a id="__codelineno-26-58" name="__codelineno-26-58" href="#__codelineno-26-58"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-26-59" name="__codelineno-26-59" href="#__codelineno-26-59"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-60" name="__codelineno-26-60" href="#__codelineno-26-60"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-26-61" name="__codelineno-26-61" href="#__codelineno-26-61"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部回到尾部</span>
<a id="__codelineno-26-62" name="__codelineno-26-62" href="#__codelineno-26-62"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-63" name="__codelineno-26-63" href="#__codelineno-26-63"></a><span class="w"> </span><span class="c1">// 将 num 添加到队首</span>
<a id="__codelineno-26-64" name="__codelineno-26-64" href="#__codelineno-26-64"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-65" name="__codelineno-26-65" href="#__codelineno-26-65"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-26-66" name="__codelineno-26-66" href="#__codelineno-26-66"></a><span class="p">}</span>
<a id="__codelineno-26-67" name="__codelineno-26-67" href="#__codelineno-26-67"></a>
<a id="__codelineno-26-68" name="__codelineno-26-68" href="#__codelineno-26-68"></a><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-26-69" name="__codelineno-26-69" href="#__codelineno-26-69"></a><span class="kt">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-70" name="__codelineno-26-70" href="#__codelineno-26-70"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">(</span><span class="n">deque</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-71" name="__codelineno-26-71" href="#__codelineno-26-71"></a><span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">&quot;双向队列已满</span><span class="se">\r\n</span><span class="s">&quot;</span><span class="p">);</span>
<a id="__codelineno-26-72" name="__codelineno-26-72" href="#__codelineno-26-72"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-26-73" name="__codelineno-26-73" href="#__codelineno-26-73"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-74" name="__codelineno-26-74" href="#__codelineno-26-74"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-26-75" name="__codelineno-26-75" href="#__codelineno-26-75"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-26-76" name="__codelineno-26-76" href="#__codelineno-26-76"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-26-77" name="__codelineno-26-77" href="#__codelineno-26-77"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-78" name="__codelineno-26-78" href="#__codelineno-26-78"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-26-79" name="__codelineno-26-79" href="#__codelineno-26-79"></a><span class="p">}</span>
<a id="__codelineno-26-80" name="__codelineno-26-80" href="#__codelineno-26-80"></a>
<a id="__codelineno-26-81" name="__codelineno-26-81" href="#__codelineno-26-81"></a><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-26-82" name="__codelineno-26-82" href="#__codelineno-26-82"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-83" name="__codelineno-26-83" href="#__codelineno-26-83"></a><span class="w"> </span><span class="c1">// 访问异常：双向队列为空</span>
<a id="__codelineno-26-84" name="__codelineno-26-84" href="#__codelineno-26-84"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-26-85" name="__codelineno-26-85" href="#__codelineno-26-85"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-26-86" name="__codelineno-26-86" href="#__codelineno-26-86"></a><span class="p">}</span>
<a id="__codelineno-26-87" name="__codelineno-26-87" href="#__codelineno-26-87"></a>
<a id="__codelineno-26-88" name="__codelineno-26-88" href="#__codelineno-26-88"></a><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-26-89" name="__codelineno-26-89" href="#__codelineno-26-89"></a><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-90" name="__codelineno-26-90" href="#__codelineno-26-90"></a><span class="w"> </span><span class="c1">// 访问异常：双向队列为空</span>
<a id="__codelineno-26-91" name="__codelineno-26-91" href="#__codelineno-26-91"></a><span class="w"> </span><span class="n">assert</span><span class="p">(</span><span class="n">empty</span><span class="p">(</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
<a id="__codelineno-26-92" name="__codelineno-26-92" href="#__codelineno-26-92"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-93" name="__codelineno-26-93" href="#__codelineno-26-93"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-26-94" name="__codelineno-26-94" href="#__codelineno-26-94"></a><span class="p">}</span>
<a id="__codelineno-26-95" name="__codelineno-26-95" href="#__codelineno-26-95"></a>
<a id="__codelineno-26-96" name="__codelineno-26-96" href="#__codelineno-26-96"></a><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-26-97" name="__codelineno-26-97" href="#__codelineno-26-97"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-98" name="__codelineno-26-98" href="#__codelineno-26-98"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-26-99" name="__codelineno-26-99" href="#__codelineno-26-99"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-26-100" name="__codelineno-26-100" href="#__codelineno-26-100"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">dequeIndex</span><span class="p">(</span><span class="n">deque</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<a id="__codelineno-26-101" name="__codelineno-26-101" href="#__codelineno-26-101"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-26-102" name="__codelineno-26-102" href="#__codelineno-26-102"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-103" name="__codelineno-26-103" href="#__codelineno-26-103"></a><span class="p">}</span>
<a id="__codelineno-26-104" name="__codelineno-26-104" href="#__codelineno-26-104"></a>
<a id="__codelineno-26-105" name="__codelineno-26-105" href="#__codelineno-26-105"></a><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-26-106" name="__codelineno-26-106" href="#__codelineno-26-106"></a><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-107" name="__codelineno-26-107" href="#__codelineno-26-107"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">(</span><span class="n">deque</span><span class="p">);</span>
<a id="__codelineno-26-108" name="__codelineno-26-108" href="#__codelineno-26-108"></a><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-26-109" name="__codelineno-26-109" href="#__codelineno-26-109"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-26-110" name="__codelineno-26-110" href="#__codelineno-26-110"></a><span class="p">}</span>
<a id="__codelineno-26-111" name="__codelineno-26-111" href="#__codelineno-26-111"></a>
<a id="__codelineno-26-112" name="__codelineno-26-112" href="#__codelineno-26-112"></a><span class="cm">/* 打印队列 */</span>
<a id="__codelineno-26-113" name="__codelineno-26-113" href="#__codelineno-26-113"></a><span class="kt">void</span><span class="w"> </span><span class="nf">printArrayDeque</span><span class="p">(</span><span class="n">arrayDeque</span><span class="w"> </span><span class="o">*</span><span class="n">deque</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-114" name="__codelineno-26-114" href="#__codelineno-26-114"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-26-115" name="__codelineno-26-115" href="#__codelineno-26-115"></a><span class="w"> </span><span class="c1">// 拷贝</span>
<a id="__codelineno-26-116" name="__codelineno-26-116" href="#__codelineno-26-116"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-26-117" name="__codelineno-26-117" href="#__codelineno-26-117"></a><span class="w"> </span><span class="n">arr</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">nums</span><span class="p">[</span><span class="n">j</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queCapacity</span><span class="p">];</span>
<a id="__codelineno-26-118" name="__codelineno-26-118" href="#__codelineno-26-118"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-26-119" name="__codelineno-26-119" href="#__codelineno-26-119"></a><span class="w"> </span><span class="n">printArray</span><span class="p">(</span><span class="n">arr</span><span class="p">,</span><span class="w"> </span><span class="n">deque</span><span class="o">-&gt;</span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-26-120" name="__codelineno-26-120" href="#__codelineno-26-120"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.cs</span><pre><span></span><code><a id="__codelineno-27-1" name="__codelineno-27-1" href="#__codelineno-27-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-27-2" name="__codelineno-27-2" href="#__codelineno-27-2"></a><span class="k">class</span><span class="w"> </span><span class="nc">ArrayDeque</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-3" name="__codelineno-27-3" href="#__codelineno-27-3"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="k">readonly</span><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="n">nums</span><span class="p">;</span><span class="w"> </span><span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-27-4" name="__codelineno-27-4" href="#__codelineno-27-4"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-27-5" name="__codelineno-27-5" href="#__codelineno-27-5"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="c1">// 双向队列长度</span>
<a id="__codelineno-27-6" name="__codelineno-27-6" href="#__codelineno-27-6"></a>
<a id="__codelineno-27-7" name="__codelineno-27-7" href="#__codelineno-27-7"></a><span class="w"> </span><span class="cm">/* 构造方法 */</span>
<a id="__codelineno-27-8" name="__codelineno-27-8" href="#__codelineno-27-8"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="nf">ArrayDeque</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">capacity</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-9" name="__codelineno-27-9" href="#__codelineno-27-9"></a><span class="w"> </span><span class="k">this</span><span class="p">.</span><span class="n">nums</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="p">[</span><span class="n">capacity</span><span class="p">];</span>
<a id="__codelineno-27-10" name="__codelineno-27-10" href="#__codelineno-27-10"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-27-11" name="__codelineno-27-11" href="#__codelineno-27-11"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-12" name="__codelineno-27-12" href="#__codelineno-27-12"></a>
<a id="__codelineno-27-13" name="__codelineno-27-13" href="#__codelineno-27-13"></a><span class="w"> </span><span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-27-14" name="__codelineno-27-14" href="#__codelineno-27-14"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">capacity</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-15" name="__codelineno-27-15" href="#__codelineno-27-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">Length</span><span class="p">;</span>
<a id="__codelineno-27-16" name="__codelineno-27-16" href="#__codelineno-27-16"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-17" name="__codelineno-27-17" href="#__codelineno-27-17"></a>
<a id="__codelineno-27-18" name="__codelineno-27-18" href="#__codelineno-27-18"></a><span class="w"> </span><span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-27-19" name="__codelineno-27-19" href="#__codelineno-27-19"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">size</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-20" name="__codelineno-27-20" href="#__codelineno-27-20"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span>
<a id="__codelineno-27-21" name="__codelineno-27-21" href="#__codelineno-27-21"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-22" name="__codelineno-27-22" href="#__codelineno-27-22"></a>
<a id="__codelineno-27-23" name="__codelineno-27-23" href="#__codelineno-27-23"></a><span class="w"> </span><span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-27-24" name="__codelineno-27-24" href="#__codelineno-27-24"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="nf">isEmpty</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-25" name="__codelineno-27-25" href="#__codelineno-27-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">0</span><span class="p">;</span>
<a id="__codelineno-27-26" name="__codelineno-27-26" href="#__codelineno-27-26"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-27" name="__codelineno-27-27" href="#__codelineno-27-27"></a>
<a id="__codelineno-27-28" name="__codelineno-27-28" href="#__codelineno-27-28"></a><span class="w"> </span><span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-27-29" name="__codelineno-27-29" href="#__codelineno-27-29"></a><span class="w"> </span><span class="k">private</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">index</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-30" name="__codelineno-27-30" href="#__codelineno-27-30"></a><span class="w"> </span><span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-27-31" name="__codelineno-27-31" href="#__codelineno-27-31"></a><span class="w"> </span><span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-27-32" name="__codelineno-27-32" href="#__codelineno-27-32"></a><span class="w"> </span><span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-27-33" name="__codelineno-27-33" href="#__codelineno-27-33"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">capacity</span><span class="p">();</span>
<a id="__codelineno-27-34" name="__codelineno-27-34" href="#__codelineno-27-34"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-35" name="__codelineno-27-35" href="#__codelineno-27-35"></a>
<a id="__codelineno-27-36" name="__codelineno-27-36" href="#__codelineno-27-36"></a><span class="w"> </span><span class="cm">/* 队首入队 */</span>
<a id="__codelineno-27-37" name="__codelineno-27-37" href="#__codelineno-27-37"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">pushFirst</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-38" name="__codelineno-27-38" href="#__codelineno-27-38"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-39" name="__codelineno-27-39" href="#__codelineno-27-39"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-27-40" name="__codelineno-27-40" href="#__codelineno-27-40"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-27-41" name="__codelineno-27-41" href="#__codelineno-27-41"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-42" name="__codelineno-27-42" href="#__codelineno-27-42"></a><span class="w"> </span><span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-27-43" name="__codelineno-27-43" href="#__codelineno-27-43"></a><span class="w"> </span><span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-27-44" name="__codelineno-27-44" href="#__codelineno-27-44"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-45" name="__codelineno-27-45" href="#__codelineno-27-45"></a><span class="w"> </span><span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-27-46" name="__codelineno-27-46" href="#__codelineno-27-46"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-47" name="__codelineno-27-47" href="#__codelineno-27-47"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-27-48" name="__codelineno-27-48" href="#__codelineno-27-48"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-49" name="__codelineno-27-49" href="#__codelineno-27-49"></a>
<a id="__codelineno-27-50" name="__codelineno-27-50" href="#__codelineno-27-50"></a><span class="w"> </span><span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-27-51" name="__codelineno-27-51" href="#__codelineno-27-51"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="k">void</span><span class="w"> </span><span class="nf">pushLast</span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-52" name="__codelineno-27-52" href="#__codelineno-27-52"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">queSize</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">capacity</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-53" name="__codelineno-27-53" href="#__codelineno-27-53"></a><span class="w"> </span><span class="n">Console</span><span class="p">.</span><span class="n">WriteLine</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">);</span>
<a id="__codelineno-27-54" name="__codelineno-27-54" href="#__codelineno-27-54"></a><span class="w"> </span><span class="k">return</span><span class="p">;</span>
<a id="__codelineno-27-55" name="__codelineno-27-55" href="#__codelineno-27-55"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-56" name="__codelineno-27-56" href="#__codelineno-27-56"></a><span class="w"> </span><span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-27-57" name="__codelineno-27-57" href="#__codelineno-27-57"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">rear</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="p">);</span>
<a id="__codelineno-27-58" name="__codelineno-27-58" href="#__codelineno-27-58"></a><span class="w"> </span><span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-27-59" name="__codelineno-27-59" href="#__codelineno-27-59"></a><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-60" name="__codelineno-27-60" href="#__codelineno-27-60"></a><span class="w"> </span><span class="n">queSize</span><span class="o">++</span><span class="p">;</span>
<a id="__codelineno-27-61" name="__codelineno-27-61" href="#__codelineno-27-61"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-62" name="__codelineno-27-62" href="#__codelineno-27-62"></a>
<a id="__codelineno-27-63" name="__codelineno-27-63" href="#__codelineno-27-63"></a><span class="w"> </span><span class="cm">/* 队首出队 */</span>
<a id="__codelineno-27-64" name="__codelineno-27-64" href="#__codelineno-27-64"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-65" name="__codelineno-27-65" href="#__codelineno-27-65"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekFirst</span><span class="p">();</span>
<a id="__codelineno-27-66" name="__codelineno-27-66" href="#__codelineno-27-66"></a><span class="w"> </span><span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-27-67" name="__codelineno-27-67" href="#__codelineno-27-67"></a><span class="w"> </span><span class="n">front</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-68" name="__codelineno-27-68" href="#__codelineno-27-68"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-27-69" name="__codelineno-27-69" href="#__codelineno-27-69"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-70" name="__codelineno-27-70" href="#__codelineno-27-70"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-71" name="__codelineno-27-71" href="#__codelineno-27-71"></a>
<a id="__codelineno-27-72" name="__codelineno-27-72" href="#__codelineno-27-72"></a><span class="w"> </span><span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-27-73" name="__codelineno-27-73" href="#__codelineno-27-73"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">popLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-74" name="__codelineno-27-74" href="#__codelineno-27-74"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">num</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">peekLast</span><span class="p">();</span>
<a id="__codelineno-27-75" name="__codelineno-27-75" href="#__codelineno-27-75"></a><span class="w"> </span><span class="n">queSize</span><span class="o">--</span><span class="p">;</span>
<a id="__codelineno-27-76" name="__codelineno-27-76" href="#__codelineno-27-76"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">num</span><span class="p">;</span>
<a id="__codelineno-27-77" name="__codelineno-27-77" href="#__codelineno-27-77"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-78" name="__codelineno-27-78" href="#__codelineno-27-78"></a>
<a id="__codelineno-27-79" name="__codelineno-27-79" href="#__codelineno-27-79"></a><span class="w"> </span><span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-27-80" name="__codelineno-27-80" href="#__codelineno-27-80"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekFirst</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-81" name="__codelineno-27-81" href="#__codelineno-27-81"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-82" name="__codelineno-27-82" href="#__codelineno-27-82"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">InvalidOperationException</span><span class="p">();</span>
<a id="__codelineno-27-83" name="__codelineno-27-83" href="#__codelineno-27-83"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-84" name="__codelineno-27-84" href="#__codelineno-27-84"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">];</span>
<a id="__codelineno-27-85" name="__codelineno-27-85" href="#__codelineno-27-85"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-86" name="__codelineno-27-86" href="#__codelineno-27-86"></a>
<a id="__codelineno-27-87" name="__codelineno-27-87" href="#__codelineno-27-87"></a><span class="w"> </span><span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-27-88" name="__codelineno-27-88" href="#__codelineno-27-88"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="nf">peekLast</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-89" name="__codelineno-27-89" href="#__codelineno-27-89"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">isEmpty</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-90" name="__codelineno-27-90" href="#__codelineno-27-90"></a><span class="w"> </span><span class="k">throw</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="nf">InvalidOperationException</span><span class="p">();</span>
<a id="__codelineno-27-91" name="__codelineno-27-91" href="#__codelineno-27-91"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-92" name="__codelineno-27-92" href="#__codelineno-27-92"></a><span class="w"> </span><span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-27-93" name="__codelineno-27-93" href="#__codelineno-27-93"></a><span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">last</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">index</span><span class="p">(</span><span class="n">front</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">queSize</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="m">1</span><span class="p">);</span>
<a id="__codelineno-27-94" name="__codelineno-27-94" href="#__codelineno-27-94"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">last</span><span class="p">];</span>
<a id="__codelineno-27-95" name="__codelineno-27-95" href="#__codelineno-27-95"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-96" name="__codelineno-27-96" href="#__codelineno-27-96"></a>
<a id="__codelineno-27-97" name="__codelineno-27-97" href="#__codelineno-27-97"></a><span class="w"> </span><span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-27-98" name="__codelineno-27-98" href="#__codelineno-27-98"></a><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="nf">toArray</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-99" name="__codelineno-27-99" href="#__codelineno-27-99"></a><span class="w"> </span><span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-27-100" name="__codelineno-27-100" href="#__codelineno-27-100"></a><span class="w"> </span><span class="kt">int</span><span class="p">[]</span><span class="w"> </span><span class="n">res</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="kt">int</span><span class="p">[</span><span class="n">queSize</span><span class="p">];</span>
<a id="__codelineno-27-101" name="__codelineno-27-101" href="#__codelineno-27-101"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="m">0</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">front</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">&lt;</span><span class="w"> </span><span class="n">queSize</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">,</span><span class="w"> </span><span class="n">j</span><span class="o">++</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<a id="__codelineno-27-102" name="__codelineno-27-102" href="#__codelineno-27-102"></a><span class="w"> </span><span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">j</span><span class="p">)];</span>
<a id="__codelineno-27-103" name="__codelineno-27-103" href="#__codelineno-27-103"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-104" name="__codelineno-27-104" href="#__codelineno-27-104"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">res</span><span class="p">;</span>
<a id="__codelineno-27-105" name="__codelineno-27-105" href="#__codelineno-27-105"></a><span class="w"> </span><span class="p">}</span>
<a id="__codelineno-27-106" name="__codelineno-27-106" href="#__codelineno-27-106"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.swift</span><pre><span></span><code><a id="__codelineno-28-1" name="__codelineno-28-1" href="#__codelineno-28-1"></a><span class="cm">/* 基于环形数组实现的双向队列 */</span>
<a id="__codelineno-28-2" name="__codelineno-28-2" href="#__codelineno-28-2"></a><span class="kd">class</span> <span class="nc">ArrayDeque</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">nums</span><span class="p">:</span> <span class="p">[</span><span class="nb">Int</span><span class="p">]</span> <span class="c1">// 用于存储双向队列元素的数组</span>
<a id="__codelineno-28-4" name="__codelineno-28-4" href="#__codelineno-28-4"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">front</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 队首指针，指向队首元素</span>
<a id="__codelineno-28-5" name="__codelineno-28-5" href="#__codelineno-28-5"></a> <span class="kd">private</span> <span class="kd">var</span> <span class="nv">queSize</span><span class="p">:</span> <span class="nb">Int</span> <span class="c1">// 双向队列长度</span>
<a id="__codelineno-28-6" name="__codelineno-28-6" href="#__codelineno-28-6"></a>
<a id="__codelineno-28-7" name="__codelineno-28-7" href="#__codelineno-28-7"></a> <span class="cm">/* 构造方法 */</span>
<a id="__codelineno-28-8" name="__codelineno-28-8" href="#__codelineno-28-8"></a> <span class="kd">init</span><span class="p">(</span><span class="n">capacity</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-28-9" name="__codelineno-28-9" href="#__codelineno-28-9"></a> <span class="n">nums</span> <span class="p">=</span> <span class="nb">Array</span><span class="p">(</span><span class="n">repeating</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="bp">count</span><span class="p">:</span> <span class="n">capacity</span><span class="p">)</span>
<a id="__codelineno-28-10" name="__codelineno-28-10" href="#__codelineno-28-10"></a> <span class="n">front</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-28-11" name="__codelineno-28-11" href="#__codelineno-28-11"></a> <span class="n">queSize</span> <span class="p">=</span> <span class="mi">0</span>
<a id="__codelineno-28-12" name="__codelineno-28-12" href="#__codelineno-28-12"></a> <span class="p">}</span>
<a id="__codelineno-28-13" name="__codelineno-28-13" href="#__codelineno-28-13"></a>
<a id="__codelineno-28-14" name="__codelineno-28-14" href="#__codelineno-28-14"></a> <span class="cm">/* 获取双向队列的容量 */</span>
<a id="__codelineno-28-15" name="__codelineno-28-15" href="#__codelineno-28-15"></a> <span class="kd">func</span> <span class="nf">capacity</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-16" name="__codelineno-28-16" href="#__codelineno-28-16"></a> <span class="n">nums</span><span class="p">.</span><span class="bp">count</span>
<a id="__codelineno-28-17" name="__codelineno-28-17" href="#__codelineno-28-17"></a> <span class="p">}</span>
<a id="__codelineno-28-18" name="__codelineno-28-18" href="#__codelineno-28-18"></a>
<a id="__codelineno-28-19" name="__codelineno-28-19" href="#__codelineno-28-19"></a> <span class="cm">/* 获取双向队列的长度 */</span>
<a id="__codelineno-28-20" name="__codelineno-28-20" href="#__codelineno-28-20"></a> <span class="kd">func</span> <span class="nf">size</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-21" name="__codelineno-28-21" href="#__codelineno-28-21"></a> <span class="n">queSize</span>
<a id="__codelineno-28-22" name="__codelineno-28-22" href="#__codelineno-28-22"></a> <span class="p">}</span>
<a id="__codelineno-28-23" name="__codelineno-28-23" href="#__codelineno-28-23"></a>
<a id="__codelineno-28-24" name="__codelineno-28-24" href="#__codelineno-28-24"></a> <span class="cm">/* 判断双向队列是否为空 */</span>
<a id="__codelineno-28-25" name="__codelineno-28-25" href="#__codelineno-28-25"></a> <span class="kd">func</span> <span class="nf">isEmpty</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Bool</span> <span class="p">{</span>
<a id="__codelineno-28-26" name="__codelineno-28-26" href="#__codelineno-28-26"></a> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="mi">0</span>
<a id="__codelineno-28-27" name="__codelineno-28-27" href="#__codelineno-28-27"></a> <span class="p">}</span>
<a id="__codelineno-28-28" name="__codelineno-28-28" href="#__codelineno-28-28"></a>
<a id="__codelineno-28-29" name="__codelineno-28-29" href="#__codelineno-28-29"></a> <span class="cm">/* 计算环形数组索引 */</span>
<a id="__codelineno-28-30" name="__codelineno-28-30" href="#__codelineno-28-30"></a> <span class="kd">private</span> <span class="kd">func</span> <span class="nf">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-31" name="__codelineno-28-31" href="#__codelineno-28-31"></a> <span class="c1">// 通过取余操作实现数组首尾相连</span>
<a id="__codelineno-28-32" name="__codelineno-28-32" href="#__codelineno-28-32"></a> <span class="c1">// 当 i 越过数组尾部后，回到头部</span>
<a id="__codelineno-28-33" name="__codelineno-28-33" href="#__codelineno-28-33"></a> <span class="c1">// 当 i 越过数组头部后，回到尾部</span>
<a id="__codelineno-28-34" name="__codelineno-28-34" href="#__codelineno-28-34"></a> <span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="n">capacity</span><span class="p">())</span> <span class="o">%</span> <span class="n">capacity</span><span class="p">()</span>
<a id="__codelineno-28-35" name="__codelineno-28-35" href="#__codelineno-28-35"></a> <span class="p">}</span>
<a id="__codelineno-28-36" name="__codelineno-28-36" href="#__codelineno-28-36"></a>
<a id="__codelineno-28-37" name="__codelineno-28-37" href="#__codelineno-28-37"></a> <span class="cm">/* 队首入队 */</span>
<a id="__codelineno-28-38" name="__codelineno-28-38" href="#__codelineno-28-38"></a> <span class="kd">func</span> <span class="nf">pushFirst</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-28-39" name="__codelineno-28-39" href="#__codelineno-28-39"></a> <span class="k">if</span> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="n">capacity</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-40" name="__codelineno-28-40" href="#__codelineno-28-40"></a> <span class="bp">print</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-28-41" name="__codelineno-28-41" href="#__codelineno-28-41"></a> <span class="k">return</span>
<a id="__codelineno-28-42" name="__codelineno-28-42" href="#__codelineno-28-42"></a> <span class="p">}</span>
<a id="__codelineno-28-43" name="__codelineno-28-43" href="#__codelineno-28-43"></a> <span class="c1">// 队首指针向左移动一位</span>
<a id="__codelineno-28-44" name="__codelineno-28-44" href="#__codelineno-28-44"></a> <span class="c1">// 通过取余操作，实现 front 越过数组头部后回到尾部</span>
<a id="__codelineno-28-45" name="__codelineno-28-45" href="#__codelineno-28-45"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-46" name="__codelineno-28-46" href="#__codelineno-28-46"></a> <span class="c1">// 将 num 添加至队首</span>
<a id="__codelineno-28-47" name="__codelineno-28-47" href="#__codelineno-28-47"></a> <span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span> <span class="p">=</span> <span class="n">num</span>
<a id="__codelineno-28-48" name="__codelineno-28-48" href="#__codelineno-28-48"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-28-49" name="__codelineno-28-49" href="#__codelineno-28-49"></a> <span class="p">}</span>
<a id="__codelineno-28-50" name="__codelineno-28-50" href="#__codelineno-28-50"></a>
<a id="__codelineno-28-51" name="__codelineno-28-51" href="#__codelineno-28-51"></a> <span class="cm">/* 队尾入队 */</span>
<a id="__codelineno-28-52" name="__codelineno-28-52" href="#__codelineno-28-52"></a> <span class="kd">func</span> <span class="nf">pushLast</span><span class="p">(</span><span class="n">num</span><span class="p">:</span> <span class="nb">Int</span><span class="p">)</span> <span class="p">{</span>
<a id="__codelineno-28-53" name="__codelineno-28-53" href="#__codelineno-28-53"></a> <span class="k">if</span> <span class="n">size</span><span class="p">()</span> <span class="p">==</span> <span class="n">capacity</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-54" name="__codelineno-28-54" href="#__codelineno-28-54"></a> <span class="bp">print</span><span class="p">(</span><span class="s">&quot;双向队列已满&quot;</span><span class="p">)</span>
<a id="__codelineno-28-55" name="__codelineno-28-55" href="#__codelineno-28-55"></a> <span class="k">return</span>
<a id="__codelineno-28-56" name="__codelineno-28-56" href="#__codelineno-28-56"></a> <span class="p">}</span>
<a id="__codelineno-28-57" name="__codelineno-28-57" href="#__codelineno-28-57"></a> <span class="c1">// 计算尾指针，指向队尾索引 + 1</span>
<a id="__codelineno-28-58" name="__codelineno-28-58" href="#__codelineno-28-58"></a> <span class="kd">let</span> <span class="nv">rear</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="n">size</span><span class="p">())</span>
<a id="__codelineno-28-59" name="__codelineno-28-59" href="#__codelineno-28-59"></a> <span class="c1">// 将 num 添加至队尾</span>
<a id="__codelineno-28-60" name="__codelineno-28-60" href="#__codelineno-28-60"></a> <span class="n">nums</span><span class="p">[</span><span class="n">rear</span><span class="p">]</span> <span class="p">=</span> <span class="n">num</span>
<a id="__codelineno-28-61" name="__codelineno-28-61" href="#__codelineno-28-61"></a> <span class="n">queSize</span> <span class="o">+=</span> <span class="mi">1</span>
<a id="__codelineno-28-62" name="__codelineno-28-62" href="#__codelineno-28-62"></a> <span class="p">}</span>
<a id="__codelineno-28-63" name="__codelineno-28-63" href="#__codelineno-28-63"></a>
<a id="__codelineno-28-64" name="__codelineno-28-64" href="#__codelineno-28-64"></a> <span class="cm">/* 队首出队 */</span>
<a id="__codelineno-28-65" name="__codelineno-28-65" href="#__codelineno-28-65"></a> <span class="kd">func</span> <span class="nf">popFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-66" name="__codelineno-28-66" href="#__codelineno-28-66"></a> <span class="kd">let</span> <span class="nv">num</span> <span class="p">=</span> <span class="n">peekFirst</span><span class="p">()</span>
<a id="__codelineno-28-67" name="__codelineno-28-67" href="#__codelineno-28-67"></a> <span class="c1">// 队首指针向后移动一位</span>
<a id="__codelineno-28-68" name="__codelineno-28-68" href="#__codelineno-28-68"></a> <span class="n">front</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-69" name="__codelineno-28-69" href="#__codelineno-28-69"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-28-70" name="__codelineno-28-70" href="#__codelineno-28-70"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-28-71" name="__codelineno-28-71" href="#__codelineno-28-71"></a> <span class="p">}</span>
<a id="__codelineno-28-72" name="__codelineno-28-72" href="#__codelineno-28-72"></a>
<a id="__codelineno-28-73" name="__codelineno-28-73" href="#__codelineno-28-73"></a> <span class="cm">/* 队尾出队 */</span>
<a id="__codelineno-28-74" name="__codelineno-28-74" href="#__codelineno-28-74"></a> <span class="kd">func</span> <span class="nf">popLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-75" name="__codelineno-28-75" href="#__codelineno-28-75"></a> <span class="kd">let</span> <span class="nv">num</span> <span class="p">=</span> <span class="n">peekLast</span><span class="p">()</span>
<a id="__codelineno-28-76" name="__codelineno-28-76" href="#__codelineno-28-76"></a> <span class="n">queSize</span> <span class="o">-=</span> <span class="mi">1</span>
<a id="__codelineno-28-77" name="__codelineno-28-77" href="#__codelineno-28-77"></a> <span class="k">return</span> <span class="n">num</span>
<a id="__codelineno-28-78" name="__codelineno-28-78" href="#__codelineno-28-78"></a> <span class="p">}</span>
<a id="__codelineno-28-79" name="__codelineno-28-79" href="#__codelineno-28-79"></a>
<a id="__codelineno-28-80" name="__codelineno-28-80" href="#__codelineno-28-80"></a> <span class="cm">/* 访问队首元素 */</span>
<a id="__codelineno-28-81" name="__codelineno-28-81" href="#__codelineno-28-81"></a> <span class="kd">func</span> <span class="nf">peekFirst</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-82" name="__codelineno-28-82" href="#__codelineno-28-82"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-83" name="__codelineno-28-83" href="#__codelineno-28-83"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-28-84" name="__codelineno-28-84" href="#__codelineno-28-84"></a> <span class="p">}</span>
<a id="__codelineno-28-85" name="__codelineno-28-85" href="#__codelineno-28-85"></a> <span class="k">return</span> <span class="n">nums</span><span class="p">[</span><span class="n">front</span><span class="p">]</span>
<a id="__codelineno-28-86" name="__codelineno-28-86" href="#__codelineno-28-86"></a> <span class="p">}</span>
<a id="__codelineno-28-87" name="__codelineno-28-87" href="#__codelineno-28-87"></a>
<a id="__codelineno-28-88" name="__codelineno-28-88" href="#__codelineno-28-88"></a> <span class="cm">/* 访问队尾元素 */</span>
<a id="__codelineno-28-89" name="__codelineno-28-89" href="#__codelineno-28-89"></a> <span class="kd">func</span> <span class="nf">peekLast</span><span class="p">()</span> <span class="p">-&gt;</span> <span class="nb">Int</span> <span class="p">{</span>
<a id="__codelineno-28-90" name="__codelineno-28-90" href="#__codelineno-28-90"></a> <span class="k">if</span> <span class="bp">isEmpty</span><span class="p">()</span> <span class="p">{</span>
<a id="__codelineno-28-91" name="__codelineno-28-91" href="#__codelineno-28-91"></a> <span class="bp">fatalError</span><span class="p">(</span><span class="s">&quot;双向队列为空&quot;</span><span class="p">)</span>
<a id="__codelineno-28-92" name="__codelineno-28-92" href="#__codelineno-28-92"></a> <span class="p">}</span>
<a id="__codelineno-28-93" name="__codelineno-28-93" href="#__codelineno-28-93"></a> <span class="c1">// 计算尾元素索引</span>
<a id="__codelineno-28-94" name="__codelineno-28-94" href="#__codelineno-28-94"></a> <span class="kd">let</span> <span class="nv">last</span> <span class="p">=</span> <span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">front</span> <span class="o">+</span> <span class="n">size</span><span class="p">()</span> <span class="o">-</span> <span class="mi">1</span><span class="p">)</span>
<a id="__codelineno-28-95" name="__codelineno-28-95" href="#__codelineno-28-95"></a> <span class="k">return</span> <span class="n">nums</span><span class="p">[</span><span class="bp">last</span><span class="p">]</span>
<a id="__codelineno-28-96" name="__codelineno-28-96" href="#__codelineno-28-96"></a> <span class="p">}</span>
<a id="__codelineno-28-97" name="__codelineno-28-97" href="#__codelineno-28-97"></a>
<a id="__codelineno-28-98" name="__codelineno-28-98" href="#__codelineno-28-98"></a> <span class="cm">/* 返回数组用于打印 */</span>
<a id="__codelineno-28-99" name="__codelineno-28-99" href="#__codelineno-28-99"></a> <span class="kd">func</span> <span class="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-28-100" name="__codelineno-28-100" href="#__codelineno-28-100"></a> <span class="c1">// 仅转换有效长度范围内的列表元素</span>
<a id="__codelineno-28-101" name="__codelineno-28-101" href="#__codelineno-28-101"></a> <span class="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-28-102" name="__codelineno-28-102" href="#__codelineno-28-102"></a> <span class="k">for</span> <span class="p">(</span><span class="n">i</span><span class="p">,</span> <span class="n">j</span><span class="p">)</span> <span class="k">in</span> <span class="n">sequence</span><span class="p">(</span><span class="bp">first</span><span class="p">:</span> <span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">front</span><span class="p">),</span> <span class="n">next</span><span class="p">:</span> <span class="p">{</span> <span class="nv">$0</span> <span class="o">&lt;</span> <span class="kc">self</span><span class="p">.</span><span class="n">size</span><span class="p">()</span> <span class="o">-</span> <span class="mi">1</span> <span class="p">?</span> <span class="p">(</span><span class="nv">$0</span> <span class="o">+</span> <span class="mi">1</span><span class="p">,</span> <span class="nv">$1</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span> <span class="p">:</span> <span class="kc">nil</span> <span class="p">})</span> <span class="p">{</span>
<a id="__codelineno-28-103" name="__codelineno-28-103" href="#__codelineno-28-103"></a> <span class="n">res</span><span class="p">[</span><span class="n">i</span><span class="p">]</span> <span class="p">=</span> <span class="n">nums</span><span class="p">[</span><span class="n">index</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="n">j</span><span class="p">)]</span>
<a id="__codelineno-28-104" name="__codelineno-28-104" href="#__codelineno-28-104"></a> <span class="p">}</span>
<a id="__codelineno-28-105" name="__codelineno-28-105" href="#__codelineno-28-105"></a> <span class="k">return</span> <span class="n">res</span>
<a id="__codelineno-28-106" name="__codelineno-28-106" href="#__codelineno-28-106"></a> <span class="p">}</span>
<a id="__codelineno-28-107" name="__codelineno-28-107" href="#__codelineno-28-107"></a><span class="p">}</span>
</code></pre></div>
</div>
<div class="tabbed-block">
<div class="highlight"><span class="filename">array_deque.zig</span><pre><span></span><code><a id="__codelineno-29-1" name="__codelineno-29-1" href="#__codelineno-29-1"></a><span class="p">[</span><span class="n">class</span><span class="p">]{</span><span class="n">ArrayDeque</span><span class="p">}</span><span class="o">-</span><span class="p">[</span><span class="n">func</span><span class="p">]{}</span>
</code></pre></div>
</div>
</div>
</div>
<h2 id="533">5.3.3. &nbsp; 双向队列应用<a class="headerlink" href="#533" title="Permanent link">&para;</a></h2>
<p>双向队列兼具栈与队列的逻辑，<strong>因此它可以实现这两者的所有应用场景，同时提供更高的自由度</strong>。</p>
<p>我们知道，软件的“撤销”功能通常使用栈来实现：系统将每次更改操作 <code>push</code> 到栈中，然后通过 <code>pop</code> 实现撤销。然而，考虑到系统资源的限制，软件通常会限制撤销的步数（例如仅允许保存 <span class="arithmatex">\(50\)</span> 步）。当栈的长度超过 <span class="arithmatex">\(50\)</span> 时，软件需要在栈底（即队首）执行删除操作。<strong>但栈无法实现该功能，此时就需要使用双向队列来替代栈</strong>。请注意，“撤销”的核心逻辑仍然遵循栈的先入后出原则，只是双向队列能够更加灵活地实现一些额外逻辑。</p>
<h2 id="__comments">评论</h2>
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