题解 | #字符串加解密#

字符转换

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.hasNextLine()) { // 注意 while 处理多个 case
            String str1 = in.nextLine();
            String str2 = in.nextLine();
            System.out.println(jiami(str1));
            System.out.println(jiemi(str2));
        }
    }
    public static String jiami(String str) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            sb.append(charScrit(str.charAt(i)));
        }
        return sb.toString();
    }
    public static char charScrit(char a) {
        if (a >= '0' && a < '9') return (char) (a + 1);
        if (a == '9')return '0';
        if (a >= 'a' && a < 'z') return (char)(Character.toUpperCase(a) + 1);
        if (a == 'z') return 'A';
        if (a >= 'A' && a < 'Z') return (char) (Character.toLowerCase(a) + 1);
        if (a == 'Z') return 'a';
        return '.';
    }
    public static String jiemi(String str) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            sb.append(charJiemi(str.charAt(i)));
        }
        return sb.toString();
    }
    public static char charJiemi(char a) {
        if (a == '0') return '9';
        if (a > '0' && a <= '9') return (char) (a - 1);
        if (a == 'a') return 'Z';
        if (a > 'a' && a <= 'z') return (char) (Character.toUpperCase(a) - 1);
        if (a == 'A') return 'z';
        if (a > 'A' && a <= 'Z') return (char)(Character.toLowerCase(a) - 1);
        return '.';
    }
}