题解 | #字符串加解密# 格式比较简洁优雅

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String str1 = in.nextLine();
            String str2 = in.nextLine();
            StringBuilder sb1 = new StringBuilder();
            StringBuilder sb2 = new StringBuilder();

            for (int i = 0; i < str1.length(); i++) {
                sb1.append(encrypt(str1.charAt(i)));
            }

            for (int i = 0; i < str2.length(); i++) {
                sb2.append(decrypt(str2.charAt(i)));
            }

            System.out.println(sb1);
            System.out.println(sb2);
        }
    }

    //加密
    public static char encrypt(char c) {
        if (c >= 'A' && c <= 'Z') {
            c = (char) ((c - 'A' + 1) % 26 + 'a');
        } else if (c >= 'a' && c <= 'z') {
            c = (char) ((c - 'a' + 1) % 26 + 'A');
        } else if (c <= '9') {
            c = (char) ((c - '0' + 1) % 10 + '0');
        }
        return c;
    }

    //解密
    public static char decrypt(char c) {
        if (c >= 'A' && c <= 'Z') {
            c = (char) ((c - 'A' - 1 + 26) % 26 + 'a');
        } else if (c >= 'a' && c <= 'z') {
            c = (char) ((c - 'a' - 1 + 26) % 26 + 'A');
        } else if (c <= '9') {
            c = (char) ((c - '0' - 1 + 10) % 10 + '0');
        }
        return c;
    }
}