题解 | #寻找峰值#

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param nums int整型vector 
     * @return int整型
     */
    int findPeakElement(vector<int>& nums) {
        int n = nums.size();
        int l = 0;
        int r = n;
        function<pair<int, int>(int)> get = [&](int i) -> pair<int, int>{
            if(i == -1 || i == n)
            return {0, 0};
            else
            return {1, nums[i]};
        };
        int res = -1;
        while(l < r)
        {
            int mid = l + (r - l) / 2;
            if(get(mid) > get(mid - 1) && get(mid) > get(mid + 1))
            return mid;
            if(get(mid) > get(mid + 1))
            r = mid;
            else
            l = mid + 1;
        }
        return res;
    }
};