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