(高精度运算4.7.26)POJ 1220 NUMBER BASE CONVERSION(高精度数的任意进制的转换——方法:ba1----->10进制----->ba2)

package com.njupt.acm;import java.math.BigInteger;import java.util.Scanner;public class POJ_1220_1 {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int t = scanner.nextInt();while(t > 0){BigInteger ba1 = scanner.nextBigInteger();BigInteger ba2 = scanner.nextBigInteger();BigInteger sum = new BigInteger("0");String str = scanner.next();int len = str.length();int i;int count = 0;int temp;for(i = len - 1; i >= 0 ; --i){//先将输入的ba1进制的数按照给定的规则转化成10进制的数char w = str.charAt(i);temp = 0;if(Character.isDigit(w)){temp = w - '0';}else if(Character.isLowerCase(w)){temp = w - 'a' + 36;}else if(Character.isUpperCase(w)){temp = w - 'A' + 10;}sum = sum.add(new BigInteger(temp + "").multiply(ba1.pow(count++)));}BigInteger zero = new BigInteger("0");int top = 0;int stack[] = new int[2000];while(sum.compareTo(zero) != 0){//转化成指定ba2进制的数stack[++top] = sum.mod(ba2).intValue();sum = sum.divide(ba2);}System.out.println(ba1+" "+str);System.out.print(ba2+" ");if(top == 0){System.out.print(0);}while(top != 0){char w = 0;temp = stack[top--];if(temp < 10){w = (char) (temp +'0');}else if(temp>= 10 && temp < 36){w = (char) (temp +'A' - 10);}else if(temp >= 36){w = (char) (temp + 'a' - 36);}System.out.print(w);}System.out.println();System.out.println();t--;}}}