https://buuoj.cn/challenges#Java%E9%80%86%E5%90%91%E8%A7%A3%E5%AF%86

https://files.buuoj.cn/files/22ddfaaeadab32fe72719e254a0b127e/818a93f3-78b6-4e8d-a5b5-4c492695cef4.zip

https://github.com/abc123info/BlueTeamTools/releases

import java.util.ArrayList;import java.util.Scanner;
public class Reverse {    public static void main(String[] args) {        Scanner s = new Scanner(System.in);        System.out.println("Please input the flag \uff1a");        String str = s.next();        System.out.println("Your input is \uff1a");        System.out.println(str);        char[] stringArr = str.toCharArray();        Encrypt(stringArr);    }
    public static void Encrypt(char[] arr) {        ArrayList<Integer> Resultlist = new ArrayList();
        for(int i = 0; i < arr.length; ++i) {            int result = arr[i] + 64 ^ 32;            Resultlist.add(result);        }
        int[] KEY = new int[]{180, 136, 137, 147, 191, 137, 147, 191, 148, 136, 133, 191, 134, 140, 129, 135, 191, 65};        ArrayList<Integer> KEYList = new ArrayList();
        for(int j = 0; j < KEY.length; ++j) {            KEYList.add(KEY[j]);        }
        System.out.println("Result:");        if (Resultlist.equals(KEYList)) {            System.out.println("Congratulations\uff01");        } else {            System.err.println("Error\uff01");        }
    }}

import sys
def decrypt(KEY):    original_flag = ''.join(chr(key_value - 64 ^ 32) for key_value in KEY)    return original_flag
def main():    KEY = [180, 136, 137, 147, 191, 137, 147, 191, 148, 136, 133, 191, 134, 140, 129, 135, 191, 65]
    decrypted_flag = decrypt(KEY)
    sys.stdout.buffer.write(f"Decrypted flag:\n{decrypted_flag}\n".encode('utf-8'))
if __name__ == "__main__":    main()

#include <iostream>#include <vector>
void decrypt(const std::vector<int>& KEY) {    std::string originalFlag;
    for (int j = 0; j < KEY.size(); ++j) {        int original = KEY[j] - 64 ^ 32;        originalFlag += static_cast<char>(original);    }
    std::cout << "Decrypted flag:\n" << originalFlag << std::endl;}
int main() {    std::vector<int> KEY = {180, 136, 137, 147, 191, 137, 147, 191, 148, 136, 133, 191, 134, 140, 129, 135, 191, 65};    decrypt(KEY);
    return 0;}

flag{This_is_the_flag_!}