题目链接

https://leetcode.cn/problems/sqrtx/description/

代码

class Solution {
public:
    int mySqrt(int x) {
        int right = x, left = 0, ans = -1;
        while(left <= right){
            long long mid = left + (right - left) / 2;
            if(mid * mid <= x){
                ans = mid;
                left = mid +1;
            }
            else{
                right = mid - 1;
                
            }
        }
        return ans;

    }
};