class Solution {
public:
    /**
     * 
     * @param x int整型 
     * @return int整型
     */
    int mysqrt(int x) {
        // write code here
        int maxx=46341,minn=0;
        while(maxx-minn>1){
            int mid=(minn+maxx)/2;
            if(mid*mid>x)maxx=mid;
            else minn=mid;
        }
        return minn;
    }
};