题目链接：162. 寻找峰值

看思路图：

class Solution {
public:
    int findPeakElement(vector<int>& nums) {
        int left = 0,right = nums.size()-1;
        while(left<right)
        {
            int mid = left + (right-left)/2;
            if(nums[mid]>nums[mid+1])
            {
                right = mid;
            }
            else if(nums[mid]<nums[mid+1])
            {
                left = mid+1;
            }
        }
        return left;
    }
};