#include <iostream>
#include <cmath>
#include <Windows.h>
#include <string>
#include <fstream>
using namespace std;
const int A = 21;
const int C = 33;
const int B = 256;

int main()
{
    setlocale(LC_ALL, "Russian");
    SetConsoleCP(1251);
    SetConsoleOutputCP(1251);

    fstream in("Source.txt", ios_base::in);
    fstream out("Output.txt",ios_base::out, ios_base::trunc);
    fstream out2("OutputRas.txt",ios_base::out, ios_base::trunc);
    string s;
    unsigned char k[2047]; unsigned char z[2047];
 /*
    cout << endl;




    cout << "Расшифровка: ";
    for (int i = 0; i < l; i++) {
        cout << k[i];
    }*/
    cout << "Меню\n1 - Зашифровать\n2 - расшифровать\nВведите номер функции: "; int choice; cin >> choice;
    switch (choice)
    {
    case 1:{
        system("cls");
        while (!in.eof())
            getline(in, s);
        //cout << "Введите сообщения для зашифровки: "; getline(cin,s);
        int l = s.length();
        for (int i = 0; i < l; i++) k[i] = s[i];
        int* T = new int[l];
        T[0] = 20;
        for (int i = 1; i < l; i++) {
            T[i] = (A * T[i - 1] + C) % B;
        }
        system("cls");
        cout << "Исходный текст:\t\t";
        for (int i = 0; i < l; i++) cout << k[i] << "\t";
        cout << endl;
        cout << "ASCII код:\t\t";
        for (int i = 0; i < l; i++) cout << (int)k[i] << "\t";
        cout << endl;
        cout << "Гамма шифр:\t\t";
        for (int i = 0; i < l; i++) cout << T[i] << "\t";
        cout << endl;
        cout << "ASCII код + Гамма шифр:\t";
        for (int i = 0; i < l; i++) {
            k[i] = k[i] + T[i];
            if (k[i] >= 256) {
                int temp = T[i] / 256;
                k[i] = k[i] - 256 * temp;
            }
            z[i] = k[i];
            cout << (int)z[i] << "\t";
        }
        cout << endl;
        cout << "Зашифрованный текст:\t";
        for (int i = 0; i < l; i++) {
            out << z[i];
            cout << z[i] << "\t";
        }
        cout << endl << endl;
        cout << "Исходный текст: " << s << endl;
        cout << "Зашифрованный текст: ";
        for (int i = 0; i < l; i++) {
            cout << z[i];
        }
        cout << endl;
        in.close();
        out.close();
        out2.close();
    }
        break;
    case 2: {
        system("cls");
        out.open("Output.txt", ios_base::in);
        out2.open("OutputRas.txt", ios_base::out, ios_base::trunc);
        while (!out2.eof())
            getline(out2, s);
        int l = s.length();
        int* T = new int[l];
        T[0] = 20;
        for (int i = 1; i < l; i++) {
            T[i] = (A * T[i - 1] + C) % B;
        }

        for (int i = 0; i < l; i++) k[i] = s[i];
        cout << "Расшифровка:\t\t";
        for (int i = 0; i < l; i++) {
            k[i] = (int)k[i] - T[i];
            if ((int)k[i] < 0) {
                int temp = (int)k[i] / 256;
                k[i] = k[i] + temp * 256;
            }
            out2 << k[i];
            cout << (int)k[i] << "\t";
        }
    }
        break;
    }
}