Leetcode69_Sqrt(x).cpp

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


 
        }
       return ans;  
    }

     
};