Divided Land http://acm.hdu.edu.cn/showproblem.php?pid=5050

Main.java

/**
 *  @author 叶剑飞
 *  @date   2014-10-03
 *  @brief  Divided Land
 *  @note   http://acm.hdu.edu.cn/showproblem.php?pid=5050
 *  @copyright  To the extent possible under law, the author has dedicated all copyright
 *  and related and neighboring rights to this software to the public domain
 *  worldwide. This software is distributed without any warranty.
 *  You should have received a copy of the CC0 Public Domain Dedication along with
 *  this software. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
 */
import java.io.*;
import java.util.*;
import java.math.BigInteger;

class Main
{
	public static void main(String [] args)
	{
		BigInteger a, b, c;
		int i, n;
		Scanner cin = new Scanner(System.in);
		n = cin.nextInt();
		for ( i = 1; i <= n; ++ i)
		{
			a = new BigInteger(cin.next(), 2);
			b = new BigInteger(cin.next(), 2);
			c = a.gcd(b);
			System.out.printf("Case #%d: %s", i, c.toString(2));
			System.out.println();
		}
	}
}