class Solution {
public:
    /*
     * @param x: An integer
     * @return: The sqrt of x
     */
    int sqrt(int x) {
        // write your code here
       if(x==0) return 0;
       double pre=0,res=1;
       while(pre!=res)
       {
           pre=res;
           res=(res+x/res)/2;
       }
       return res;
    }
};