#include<iostream>
#include<conio.h>
using namespace std;
void encryption(int key,char m[]);
void decryption(int key,char m[]);
int main()
{
    int key,v;
    char *m = new char;
    cout << "Key:"; cin >> key;
    cout << "Text:";
    cin.getline(m,sizeof(m));
    cout << "1-encryption;2-decryption"; cin >> v;
    switch (v)
    {
    case 1: encryption(key,m); break;
    case 2: decryption(key,m); break;
    }
    delete[]m;
    system("pause");
    return 0;
}
void encryption(int key,char m[])
{
    for (int i = 0; i < '\0'; i++)
    {
        if ((m[i] >= 'A' && m[i] <= 'Z') || (m[i] >= 'a' && m[i] <= 'z'))
        {
            if (m[i] >= 'A' && m[i] <= 'Z')
            {
                static_cast<int>(m[i]);
                m[i] = (m[i] + key + 41) % 26;
                static_cast<char>(m[i]);
            }
            else
            {
                static_cast<int>(m[i]);
                m[i] = (m[i] + key + 61) % 26;
                static_cast<char>(m[i]);
            }
        }
    }
    cout << m << endl;
}
void decryption(int key,char m[])
{
    for (int i = 0; i < '\0'; i++)
    {
        if ((m[i] >= 'A' && m[i] <= 'Z') || (m[i] >= 'a' && m[i] <= 'z'))
        {
            if (m[i] >= 'A' && m[i] <= 'Z')
            {
                static_cast<int>(m[i]);
                m[i] = (m[i] + key + 15) % 26;
                static_cast<char>(m[i]);
            }
            else
            {
                static_cast<int>(m[i]);
                m[i] = (m[i] - key + 35) % 26;
                static_cast<char>(m[i]);
            }
        }
    }
    cout << m << endl;
}