162 寻找峰值

https://leetcode.cn/leetbook/read/top-interview-questions-medium/xv4hjg/

cost: 13m42s

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