题解 | #字符串加解密#

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            String str1 = sc.nextLine();
            String str2 = sc.nextLine();
            System.out.println(encode(str1));
            System.out.println(uncode(str2));
        }
        
    }
    //加密方法
    public static String encode(String str){
        char[] arr = str.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(char c : arr){
            if(Character.isLetter(c)){
                if(c == 'Z'){
                    sb.append('a');
                }
                if(c == 'z'){
                    sb.append('A');
                }
                if(c >= 'A' && c < 'Z'){
                    sb.append((char)(c+33));
                }
                if(c >= 'a' && c < 'z'){
                    sb.append((char)(c-31));
                }
            }
            if(Character.isDigit(c)){
                if(c == '9'){
                    sb.append('0');
                }else{
                    sb.append((char)(c+1));
                }
            }
        }
        return sb.toString();
    }
    
        //解密方法
    public static String uncode(String str){
        char[] arr = str.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(char c : arr){
            if(Character.isLetter(c)){
                if(c == 'a'){
                    sb.append('Z');
                }
                if(c == 'A'){
                    sb.append('z');
                }
                if(c > 'A' && c <= 'Z'){
                    sb.append((char)(c+31));
                }
                if(c > 'a' && c <= 'z'){
                    sb.append((char)(c-33));
                }
            }
            if(Character.isDigit(c)){
                if(c == '0'){
                    sb.append('9');
                }else{
                    sb.append((char)(c-1));
                }
            }
        }
        return sb.toString();
    }
}