机试题：进制转换

今日份AC

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;

public class Main {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String str="";
		while((str=br.readLine())!=null) {
			BigInteger bi=new BigInteger(str);
			String ss=bi.toString(2);
			System.out.println(ss);
		}
	}

}