题目1138：进制转换

import java.util.Scanner;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.IOException;
import java.math.BigInteger;

class Main
{
private final static boolean DEBUG = false;

public static void main(String[] args) throws IOException
{
Scanner cin;
BigInteger a;

if (DEBUG) {
cin = new Scanner(new BufferedReader(new FileReader("d:\\OJ\\uva_in.txt")));
} else {
cin = new Scanner(System.in);
}

while (cin.hasNext()) {
a = cin.nextBigInteger();

if (a.compareTo(BigInteger.ZERO) == 0) {
System.out.println("0");
continue;
}

StringBuffer tmp = new StringBuffer();
while (a.compareTo(BigInteger.ZERO) != 0) {
BigInteger re = a.remainder(BigInteger.valueOf(2));
tmp.append(re.toString());
a = a.divide(BigInteger.valueOf(2));
}

System.out.println(tmp.reverse().toString());
}
}
}