一、相关概念

如何根据字母得到对应数字

将'0'-'9'映射到数字0-9，将'a'-'z'映射到数字10-35的方法

将'0'-'9'，'a'-'z'存储到List中，index是0-35为其对应的数字

static Character[] nums = { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' };

static List list = Arrays.asList(nums);

int index = list.indexOf('p');// 得到的是25

利用ASCII码

//找到字符对应的整数

public static int getInt(char a){

if(a>='0'&&a

return (a - 'a') + 10;

}

}

二、题目

题目

36进制由0-9，a-z，共36个字符表示，最小为'0'

'0''9'对应十进制的09，'a''z'对应十进制的1035

例如：'1b' 换算成10进制等于 1 * 36^1 + 11 * 36^0 = 36 + 11 = 47

要求按照加法规则计算出任意两个36进制正整数的和

如：按照加法规则，计算'1b' + '2x' = '48'

要求：不允许把36进制数字整体转为10进制数字，计算出10进制数字的相加结果再转回为36进制

思路

按照十进制的加法方法，满36向前进一位

代码

import java.util.Arrays;

import java.util.List;

import java.util.Scanner;

public class 进制转换 {

static Character[] nums = { '0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' };

static List list = Arrays.asList(nums);

public static void main(String[] args) {

Scanner scan=new Scanner(System.in);

String str1 = scan.next();

String str2 = scan.next();

String r=f(str1,str2);

System.out.println(r);

}

static String f(String str1, String str2) {

char[] s1 = str1.toCharArray();

char[] s2 = str2.toCharArray();

int i = s1.length - 1;

int j = s2.length - 1;

int temp = 0;// 进位

StringBuilder sb = new StringBuilder();

while (i >= 0 && j >= 0) {

char c1 = s1[i];

char c2 = s2[j];

int index1 = list.indexOf(c1);

int index2 = list.indexOf(c2);

int sum = index1 + index2 + temp;

if (sum >= 36) {

temp = 1;

sb.append(list.get(sum % 36));

} else {

temp=0;

sb.append(list.get(sum));

}

i--;

j--;

}

while (i >= 0) {

int sum = list.indexOf(s1[i]) + temp;

if (sum >=36) {

temp = 1;

sb.append(list.get(sum % 36));

} else {

temp=0;

sb.append(list.get(sum));

}

i--;

}

while (j >= 0) {

int sum = list.indexOf(s2[j]) + temp;

if (sum >=36) {

temp = 1;

sb.append(list.get(sum % 36));

} else {

temp=0;

sb.append(list.get(sum));

}

j--;

}

if(temp!=0){

sb.append('1');

}

return sb.reverse().toString();

}

}

参考文献