mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-11 02:58:13 +08:00
48 lines
1.3 KiB
HTML
48 lines
1.3 KiB
HTML
符合下列属性的数组 <code>arr</code> 称为 <strong>山脉数组</strong> ：
|
||
<ul>
|
||
<li><code>arr.length >= 3</code></li>
|
||
<li>存在 <code>i</code>（<code>0 < i < arr.length - 1</code>）使得：
|
||
<ul>
|
||
<li><code>arr[0] < arr[1] < ... arr[i-1] < arr[i] </code></li>
|
||
<li><code>arr[i] > arr[i+1] > ... > arr[arr.length - 1]</code></li>
|
||
</ul>
|
||
</li>
|
||
</ul>
|
||
|
||
<p>给你由整数组成的山脉数组 <code>arr</code> ，返回满足 <code>arr[0] < arr[1] < ... arr[i - 1] < arr[i] > arr[i + 1] > ... > arr[arr.length - 1]</code> 的下标 <code>i</code> 。</p>
|
||
|
||
<p>你必须设计并实现时间复杂度为 <code>O(log(n))</code> 的解决方案。</p>
|
||
|
||
<p> </p>
|
||
|
||
<p><strong>示例 1：</strong></p>
|
||
|
||
<pre>
|
||
<strong>输入：</strong>arr = [0,1,0]
|
||
<strong>输出：</strong>1
|
||
</pre>
|
||
|
||
<p><strong>示例 2：</strong></p>
|
||
|
||
<pre>
|
||
<strong>输入：</strong>arr = [0,2,1,0]
|
||
<strong>输出：</strong>1
|
||
</pre>
|
||
|
||
<p><strong>示例 3：</strong></p>
|
||
|
||
<pre>
|
||
<strong>输入：</strong>arr = [0,10,5,2]
|
||
<strong>输出：</strong>1
|
||
</pre>
|
||
|
||
<p> </p>
|
||
|
||
<p><strong>提示：</strong></p>
|
||
|
||
<ul>
|
||
<li><code>3 <= arr.length <= 10<sup>5</sup></code></li>
|
||
<li><code>0 <= arr[i] <= 10<sup>6</sup></code></li>
|
||
<li>题目数据保证 <code>arr</code> 是一个山脉数组</li>
|
||
</ul>
|