sgu111 （大整数开方）

大整数开方。。。偷懒，抄了个java。。。留一下。。。回头弄一下java的大数模板

import java.io.*;import java.math.*;import java.util.*;public class Solution {public static void main(String[] args) {BigInteger r = new BigInteger("10");BigInteger l = new BigInteger("1");BigInteger one = new BigInteger("1");int tmp,cmp;BigInteger x,mid,ans;r = r.pow(500);Scanner cin = new Scanner(new BufferedInputStream(System.in));x = cin.nextBigInteger();ans = new BigInteger("-1");cmp = l.compareTo(r);while(cmp<=0){mid = (l.add(r)).shiftRight(1);tmp = (mid.pow(2)).compareTo(x);if(tmp<=0){ans=mid;l=mid.add(one);}else r=mid.subtract(one);cmp = l.compareTo(r);}System.out.println(ans);}}