libraryf

#include "stdafx.h"
#include <string>
#include <iostream>
using namespace std;

int charToNum(char c)

{

	return int(c) - 97;

}

int main()
{
	setlocale(0, "RUS");
	string M;
	cout << "Введите открытый текст: " << endl;
	cin >> M;
	int L = M.length();
	string grnk;
	cout << "Введите ключ: " << endl;
	cin >> grnk;
	string grnk2 = grnk;
	cout << "Шифр Гронсфельда: " << endl;
	cout << "K=" << grnk << endl;
	for (int i = grnk.length(); i<M.length(); i++)
		grnk2 += grnk[i%grnk.length()];
	cout << "K=" << grnk2 << endl;
	for (int i = 0; i<L; i++) {
		if (M[i] >= 97 && M[i] <= 122)
			cout << M[i] << "=" << charToNum(M[i]) << "+" << grnk2[i] << "=" << char(97 + (charToNum(M[i]) + grnk2[i]) % 26) << endl;
		else
			cout << M[i] << ":" << "C[" << i << "]=" << M[i] << endl;
	}
	system("pause");
}