C# 69. Sqrt(x)

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