题解 | #字符串加解密#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str1 = scanner.nextLine();
        String str2 = scanner.nextLine();
        System.out.println(encryption(str1));
        System.out.println(decryption(str2));
    }

    public static String encryption (String str) {
        char[] chr = str.toCharArray();
        StringBuilder result = new StringBuilder();
        for (char c : chr) {
            if (c >= 'a' && c <= 'y') result.append((char) (Character.toUpperCase(c) + 1));
            if (c >= 'A' && c <= 'Y') result.append((char) (Character.toLowerCase(c) + 1));
            if (c >= '0' && c <= '8') result.append((char) (c + 1));
            if (c == 'z') result.append('A');
            if (c == 'Z') result.append('a');
            if (c == '9') result.append('0');
        }
        return result.toString();
    }

    public static String decryption (String str) {
        char[] chr = str.toCharArray();
        StringBuilder result = new StringBuilder();
        for (char c : chr) {
            if (c >= 'b' && c <= 'z') result.append((char) (Character.toUpperCase(c) - 1));
            if (c >= 'B' && c <= 'Z') result.append((char) (Character.toLowerCase(c) - 1));
            if (c >= '1' && c <= '9') result.append((char) (c - 1));
            if (c == 'a') result.append('Z');
            if (c == 'A') result.append('z');
            if (c == '0') result.append('9');
        }
        return result.toString();
    }
}