题解 | #字符串加解密# Character相关方法的使用

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String encode = sc.nextLine();
        String decode = sc.nextLine();
        char[] ens = encode.toCharArray();
        char[] des = decode.toCharArray();
        for (int i = 0; i < ens.length; i++) {
            ens[i] = encrypt(ens[i]);
        }
        for (int i = 0; i < des.length; i++) {
            des[i] = decrypt(des[i]);
        }
        System.out.println(new String(ens));
        System.out.println(new String(des));
        
    }
    
    /**
    * 加密
    */
    public static char encrypt(char c) {
        if (Character.isLetter(c)) {
            if (Character.isUpperCase(c)) {
                if (c == 'Z') {
                    return 'a';
                }
                int i = Character.toLowerCase(c + 1);
                return (char) i;
            } else {
                if (c == 'z') {
                    return 'A';
                }
                int i = Character.toUpperCase(c + 1);
                return (char) i;
            }
        } else if (Character.isDigit(c)) {
            if (c == '9') {
                return '0';
            } else {
                return (char) (c + 1);
            }
        } else {
            return c;
        }
    }
    
    /**
    * 解密
    */
    public static char decrypt(char c) {
        if (Character.isLetter(c)) {
            if (Character.isUpperCase(c)) {
                if (c == 'A') {
                    return 'z';
                }
                int i = Character.toLowerCase(c - 1);
                return (char) i;
            } else {
                if (c == 'a') {
                    return 'Z';
                }
                int i = Character.toUpperCase(c - 1);
                return (char) i;
            }
        } else if (Character.isDigit(c)) {
            if (c == '0') {
                return '9';
            } else {
                return (char) (c +-1);
            }
        } else {
            return c;
        }
    }
}