题解 | #求平方根#

class Solution {
public:
    /**
     * 
     * @param x int整型 
     * @return int整型
     */
    int mysqrt(int x) {
        // write code here
        int l = 0, r = x;
        while (l < r) {
            int mid = (long long) l + r + 1 >> 1;
            if ((long long) mid * mid > x) {
                r = mid - 1;
            } else {
                l = mid;
            }
        }
        return l;
    }
};