poj 1220 java大数类

[java]
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Scanner;

public class Main {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner input = new Scanner(System.in);
        int icase;
        int b1;
        int b2;
        String str;
        char ch;
        int top = 0;
        int c;
        char chh;
        int tmp;
        BigInteger sum,a;
        BigInteger t;
        int[] stack = new int[2000];
        // 余数入栈
        icase = input.nextInt();
        while ((icase--) != 0) {
             a = BigInteger.valueOf(1);
             sum = new BigInteger("0");
            b1 = input.nextInt();
            b2 = input.nextInt();
            str = input.next();
            for (int i = str.length()-1; i >= 0 ; i--) {   //先化成10进制
                tmp = 0;
                ch = str.charAt(i);
                if (ch <= '9' && ch >= '0') {
                    tmp = ch - '0';
                } else if (ch >= 'A' && ch <= 'Z') {
                    tmp = ch - 'A' + 10;
                } else if (ch >= 'a' && ch <= 'z') {
                    tmp = ch - 'a' + 36;
                }
                sum = sum.add(BigInteger.valueOf(tmp).multiply(a));
                a = a.multiply(BigInteger.valueOf(b1));
            }
            System.out.print(b1 + " " + str + "\n" + b2 + " ");
              BigInteger zero = BigInteger.valueOf(0);
              //sum != BigInteger.valueOf(0)这样不对 java不能这样比较两个对象是否相等吧
              //神马都是类。。。。。。。。。。。。受不了，不习惯
            while (sum.compareTo(zero) != 0) {
                t = sum.mod(BigInteger.valueOf(b2));
                stack[++top] = t.intValue();
                sum = sum.divide(BigInteger.valueOf(b2));
            }
            if(top == 0)
                System.out.print(0);
            while (top != 0) {
                c = stack[top--];
                if (c < 10)
                    chh = (char) (c + '0');
                else if (c < 36)
                    chh = (char) (c - 10 + 'A');
                else
                    chh = (char) (c - 36 + 'a');
                System.out.print(chh);
            }
            System.out.print("\n\n");
        }
    }

}

作者 Bill_Ming

补充：软件开发 , Java ,