https://www.dorkytiger.top/c-plus-plus/high-frequency-algorithms/06-binary-search/ Recent content in 二分搜索与变种 on Dorkytiger 的小屋 Hugo en-us https://www.dorkytiger.top/c-plus-plus/high-frequency-algorithms/06-binary-search/01-section/ Mon, 01 Jan 0001 00:00:00 +0000 https://www.dorkytiger.top/c-plus-plus/high-frequency-algorithms/06-binary-search/01-section/ <h3 id="一核心思想每次排除一半">一、核心思想——每次排除一半</h3> <p><strong>前提</strong>：数组必须有序。</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"><code class="language-text" data-lang="text"><span style="display:flex;"><span>在有序数组 [1, 3, 5, 7, 9, 11, 13, 15] 中找 7： </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span>[1, 3, 5, 7, 9, 11, 13, 15] left=0, right=7, mid=3 → nums[3]=7 ✅ 找到 </span></span><span style="display:flex;"><span> ↑mid </span></span><span style="display:flex;"><span> </span></span><span style="display:flex;"><span>如果找 6： </span></span><span style="display:flex;"><span>[1, 3, 5, 7, 9, 11, 13, 15] left=0, right=7, mid=3 → nums[3]=7 &gt;6 </span></span><span style="display:flex;"><span> left=0, right=2, mid=1 → nums[1]=3 &lt;6 </span></span><span style="display:flex;"><span> left=2, right=2, mid=2 → nums[2]=5 &lt;6 </span></span><span style="display:flex;"><span> left=3, right=2 → 退出，找不到 </span></span></code></pre></div><h3 id="二两种区间写法">二、两种区间写法</h3> <p>面试高频考点：<strong>左闭右闭 <code>[left, right]</code></strong> 和 <strong>左闭右开 <code>[left, right)</code></strong> 的区别。</p>