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 sc = new Scanner(System.in);
        while (sc.hasNext()) {
            String enstr = sc.nextLine();
            String destr = sc.nextLine();
            StringBuilder ensb = new StringBuilder();
            StringBuilder desb = new StringBuilder();
            encode(enstr, ensb);
            decode(destr, desb);
            System.out.println(ensb);
            System.out.println(desb);
        }
    }

    private static void encode(String enstr, StringBuilder ensb) {
        for (int i = 0; i < enstr.length(); i++) {
            if (enstr.charAt(i) >= 'a' && enstr.charAt(i) < 'z') {
                ensb.append(Character.toUpperCase((char)(enstr.charAt(i) + 1)));
            } else if (enstr.charAt(i) == 'z') {
                ensb.append('A');
            } else if (enstr.charAt(i) >= 'A' && enstr.charAt(i) < 'Z') {
                ensb.append(Character.toLowerCase((char)(enstr.charAt(i) + 1)));
            } else if (enstr.charAt(i) == 'Z') {
                ensb.append('a');
            } else if (enstr.charAt(i) >= '0' && enstr.charAt(i) < '9') {
                ensb.append((char)(enstr.charAt(i) + 1));
            } else if (enstr.charAt(i) == '9') {
                ensb.append('0');
            }
        }
    }

    private static void decode(String destr, StringBuilder desb) {
        for (int i = 0; i < destr.length(); i++) {
            if (destr.charAt(i) > 'a' && destr.charAt(i) <= 'z') {
                desb.append(Character.toUpperCase((char)(destr.charAt(i) - 1)));
            } else if (destr.charAt(i) == 'a') {
                desb.append('Z');
            } else if (destr.charAt(i) > 'A' && destr.charAt(i) <= 'Z') {
                desb.append(Character.toLowerCase((char)(destr.charAt(i) - 1)));
            } else if (destr.charAt(i) == 'A') {
                desb.append('z');
            } else if (destr.charAt(i) > '0' && destr.charAt(i) <= '9') {
                desb.append((char)(destr.charAt(i) - 1));
            } else if (destr.charAt(i) == '0') {
                desb.append('9');
            }
        }
    }
}