算法---二分

class Solution {
public:
   
    int findPeakElement(vector<int>& nums) {
        // write code here
        //题目只需要求一个峰值即可，我门可以利用二分法+一直向峰值逼近的策略
        int left =0;
        int right = nums.size()-1;
        while(left<right){
            int mid = (left+right)>>1;
            if(nums[mid]<nums[mid+1]){
                left = mid+1;
            }
            else{
                right = mid;
            }
        }
        return right;
    }
};