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 in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            String a = in.nextLine();
            String b = in.nextLine();
            System.out.println(jiami(a));
            System.out.println(jiemi(b));
        }
    }
    // 加密字符串
   private static String jiami(String input) {
        StringBuilder sb = new StringBuilder();
        char[] c = input.toCharArray();
        for (char c1 : c) {
            if (c1 >= 'a' && c1 < 'z') {
                char t = (char) (c1 + 1 - 32);
                sb.append(t);
            } else if (c1 == 'z') {
                sb.append("A");
            } else if (c1 >= 'A' && c1 < 'Z') {
                char t = (char) (c1 + 1 + 32);
                sb.append(t);
            } else if (c1 == 'Z') {
                sb.append("a");
            } else if (c1 >= '0' && c1 < '9') {
                sb.append(c1 + 1 - 48);
            } else if (c1 == '9') {
                sb.append("0");
            }
        }
        return sb.toString();
    }

    private static String jiemi(String input) {
        StringBuilder sb = new StringBuilder();
        char[] c = input.toCharArray();
        for (char c1 : c) {
            if (c1 > 'a' && c1 <= 'z') {
                char t = (char) (c1 - 1 - 32);
                sb.append(t);
            } else if (c1 == 'a') {
                sb.append("Z");
            } else if (c1 > 'A' && c1 <= 'Z') {
                char t = (char) (c1 - 1 + 32);
                sb.append(t);
            } else if (c1 == 'A') {
                sb.append("z");
            } else if (c1 > '0' && c1 <= '9') {
                sb.append(c1 - 1 - 48);
            } else if (c1 == '0') {
                sb.append("9");
            }
        }
        return sb.toString();
    }
}