Poj Solution 1220

http://poj.org/problem?id=1220

import java.util.*;
import java.math.*;
public class Main {
    static int c2i(char c){
        if(c>='0'&&c<='9')
            return c-'0';
        if(c>='A'&&c<='Z')
            return c-'A'+10;
        return c-'a'+36;
    }
    static char i2c(int c){
        if(c< 10)
            return (char)(48+c);
        if(c>=10&&c< 36)
            return (char)('A'+c-10);
        return (char)('a'+c-36);
    }
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        int t=in.nextInt();
        for(int k=0;k< t;k++){
            int a1=in.nextInt();
            int a2=in.nextInt();
            String s=in.next();
            System.out.println(a1+" "+s);
            System.out.print(a2+" ");
            BigInteger a=BigInteger.ZERO;
            for(int i=0;i< s.length();i++)
                a=a.multiply(BigInteger.valueOf(a1)).add(BigInteger.valueOf(c2i(s.charAt(i))));
            s="";
            while(!a.equals(BigInteger.ZERO)){
                s=i2c(a.mod(BigInteger.valueOf(a2)).intValue())+s;
                a=a.divide(BigInteger.valueOf(a2));
            }
            if(s.equals(""))
                s="0";
            System.out.println(s);
            System.out.println();
        }
    }

}