题解 | #字符串加解密#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int i=0;
        
        while (scanner.hasNextLine()){
            
            String line = scanner.nextLine();
            char[] charArray = line.toCharArray();
            
            if (i==0){
                jiami(charArray);
            } else {
                jiemi(charArray);
            }
            
            i++;
        }
    }

    public static void jiemi(char[] charArray){
        for (int i = 0; i < charArray.length; i++) {
            char c = charArray[i];
            if (Character.isLetter(c)){

                if (c=='a' || c=='A'){
                    charArray[i] +=25;
                } else {
                    charArray[i] -= 1;
                }

                if (Character.isUpperCase(charArray[i])){
                    charArray[i] = Character.toLowerCase(charArray[i]);
                } else {
                    charArray[i] = Character.toUpperCase(charArray[i]);
                }
            }
            if (Character.isDigit(c)){
                if (c=='0'){
                    charArray[i] += 9;
                } else {
                    charArray[i] -= 1;
                }
            }
        }

        String str = new String(charArray);


        System.out.println(str);
    }
    
    public static void jiami(char[] charArray){
        for (int i = 0; i < charArray.length; i++) {
            char c = charArray[i];
            if (Character.isLetter(c)){

                if (c=='z' || c=='Z'){
                    charArray[i] -=25;
                } else {
                    charArray[i] += 1;
                }

                if (Character.isUpperCase(charArray[i])){
                    charArray[i] = Character.toLowerCase(charArray[i]);
                } else {
                    charArray[i] = Character.toUpperCase(charArray[i]);
                }
            }
            if (Character.isDigit(c)){
                if (c=='9'){
                    charArray[i] -= 9;
                } else {
                    charArray[i] += 1;
                }
            }
        }

        String str = new String(charArray);


        System.out.println(str);
    }

}