#include <iostream>
#include <vector>

using namespace std;

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