POJ 1220 NUMBER BASE CONVERSION JAVA .

题目地址： http://poj.org/problem?id=1220

import java.util.*;
import java.math.*;
import java.text.*;
import java.io.*;

public class Main
{
	public static int getNum(char ch){
		if(Character.isDigit(ch)) return ch-'0';
		else if(Character.isUpperCase(ch)) return ch-'A'+10;
		else if(Character.isLowerCase(ch)) return ch-'a'+36;
		return 0;
	}
	public static char getChar(int i){
		if(i>=0&&i<=9) return (char)(i+'0');
		else if(i>=10&&i<=35) return (char)(i+'A'-10);
		else if(i>=36) return (char)(i+'a'-36);
		return '0';
	}

	public static void main(String[] args) {
		Scanner cin = new Scanner(new BufferedInputStream(System.in));

		int T=cin.nextInt();
		while(T--!=0){
			int base1=cin.nextInt(),base2=cin.nextInt();
			String s=cin.next();

			BigInteger n = BigInteger.ZERO;
			for(int i=0;i<s.length();i++){
				char ch=s.charAt(i);
				n = n.multiply(n.valueOf(base1)).add(n.valueOf(getNum(ch)));
			}

			String ans = new String();
			while(!n.equals(BigInteger.ZERO)) {
				ans=getChar(n.mod(n.valueOf(base2)).intValue())+ans;
				n=n.divide(n.valueOf(base2));
			}
			if(ans.length()==0) ans+='0';
			System.out.println(base1+" "+s);
			System.out.println(base2+" "+ans);
			System.out.println();
		}
	}
}