Square root of X

A nonnegative integer x, Calculate and return x The square root of .

Rounding off the decimal part of the result , Keep only integer parts and output .

for example ：

Input ：x=4

Output ：2

Input ：x=8

Output 2

Ideas ： Use binary search to narrow the range until the final value is found and output

int mySqrt(int x){
    int right=x;
    int left=0;
    int ans=0;
    while(left<=right){
        int mid=left+(right-left)/2; // Two points search 
            if ((double)mid * mid <= x) {
                ans = mid;
                left = mid + 1;// Update left border 
            } else {
                right = mid - 1;// Update right border 
            }
    }
    return ans;
}