// Setting the debugger’s breakpoint
// Removing a breakpoint
// Section with variables
// Moving through your program:
// Start, Stop, Restart


#include<iostream>
using namespace std;

void caesar(char message[], int key);
char validLetter(char letter, int key);


int main()
{
	char message[100];
	int key;

	cout << "Enter a message to encrypt: ";
	cin.getline(message, 100);
	cout << "Enter key: ";
	cin >> key;

	caesar(message, key);
	cout << "Encrypted message: " << message << endl;

	system("pause");
	return 0;
}

void caesar(char message[], int key) {
	for (int i = 0; message[i] != '\0'; ++i){
		message[i] = validLetter(message[i], key);
	}
}

char validLetter(char letter, int key) {
	if (letter >= 'a' && letter <= 'z'){
		letter = letter + key;

		if (letter > 'z'){
			letter = letter - 'z' + 'a' - 1;
		}
		else if (letter < 'a') {
			letter = letter - 'a' + 'z' + 1;
		}
		return letter;
	}
	else if (letter >= 'A' && letter <= 'Z'){
		letter = letter + key;

		if (letter > 'Z'){
			letter = letter - 'Z' + 'A' - 1;
		}
		else if (letter < 'A') {
			letter = letter - 'A' + 'Z' + 1;
		}
		return letter;
	}
}