题目描述：

Let's call an array A a mountain if the following properties hold:

• A.length >= 3
• There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1]

Given an array that is definitely a mountain, return any i such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1].

Example 1:

Input: [0,1,0]Output: 1

Example 2:

Input: [0,2,1,0]Output: 1

Note:

1. 3 <= A.length <= 10000
2. 0 <= A[i] <= 10^6
3. A is a mountain, as defined above.

解题思路：

题目简单，相当于找到vector中的最大值。

代码：

1 class Solution { 2 public: 3     int peakIndexInMountainArray(vector
     
      & A) { 4         for (int i = 1; i < A.size(); ++i) { 5             if (A[i] < A[i-1]) 6                 return i-1; 7         } 8         return A.size()-1; 9     }10 };