3130806_ac_219ms_5232k.java

来自「北大大牛代码 1240道题的原代码 超级权威」· Java 代码 · 共 53 行

import java.util.*;
import java.math.*;

public class Main
{
	public static void main(String [] args)
	{
		Scanner cin = new Scanner (System.in);
		BigInteger [] p3 = new BigInteger [65];
		int i;
		BigInteger num;
		
		p3[0] = new BigInteger ("1");
		p3[1] = new BigInteger ("3");
		for(i = 2; i < 65; i++)
		{
			p3[i] = p3[i-1].multiply(p3[1]);
		}
		while(true)
		{
			String str;
			str = cin.next();
			if(str.compareTo("0")==0)
			{
				break;
			}
			if(str.compareTo("1")==0)
			{
				System.out.println("{ }");
				continue;
			}
			num = new BigInteger (str);
			num = num.subtract(BigInteger.ONE);
			i = 0;
			str = "{ ";
			BigInteger two = BigInteger.ONE.add(BigInteger.ONE);
			while(num.toString().compareTo("0")!=0)
			{
				int p = num.mod(two).intValue();
				if(p==1)
				{
					str += p3[i].toString();
					str += ", ";
				}
				i++;
				num = num.divide(two);
			}
			str = str.substring(0,str.length()-2);
			str += " }";
			System.out.println(str);
		}
	}
}