刷leetcode用到的一些算法

二分法求平方根的整数部分

int mySqrt(int x) {
        int left = 0;
        int right = x;
        while (left <= right) {
            int mid = (left + right) / 2;
            if (mid*mid == x) {
                return mid;
            }
            else if (mid*mid < x) {
                left = mid + 1;
            }
            else {
                right = mid - 1;
            }
        }
        return right;
    }