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.hasNextLine()) { // 注意 while 处理多个 case
            String s = in.nextLine();
            String t = in.nextLine();
            String strEntry = "";
            String strDEntry = "";
            for (int i = 0; i < s.length(); i++) {
                char c = s.charAt(i);
                if (c >= 'A' && c <= 'Z') {
                    if (c == 'Z') {
                        strEntry = strEntry + "a";
                    } else {
                        c = (char)(c + 'a' - 'A' + 1);
                        strEntry = strEntry + c;
                    }


                } else if (c >= 'a' && c <= 'z') {
                    if (c == 'z') {
                        strEntry = strEntry + "A";
                    } else {
                        c = (char)(c - 'a' + 'A' + 1);
                        strEntry = strEntry + c;
                    }
                } else if (c >= '0' && c <= '9') {
                    if (c == '9') {
                        strEntry = strEntry + "0";
                    } else {
                        c = (char)(c  + 1);
                        strEntry = strEntry + c;
                    }
                }
            }
            for (int i = 0; i < t.length(); i++) {
                char c = t.charAt(i);
                if (c >= 'A' && c <= 'Z') {
                    if (c == 'A') {
                        strDEntry = strDEntry + "z";
                    } else {
                        c = (char)(c + 'a' - 'A' -1);
                        strDEntry = strDEntry + c;
                    }


                } else if (c >= 'a' && c <= 'z') {
                    if (c == 'a') {
                        strDEntry = strDEntry + "Z";
                    } else {
                        c = (char)(c - 'a' + 'A' -1);
                        strDEntry = strDEntry + c;
                    }
                } else if (c >= '0' && c <= '9') {
                    if (c == '0') {
                        strDEntry = strDEntry + "9";
                    } else {
                        c = (char)(c  - 1);
                        strDEntry = strDEntry + c;
                    }
                }
            }
            System.out.println(strEntry);
            System.out.println(strDEntry);

        }
    }
}