main.cpp

#include "playfair.h"
#include <cctype>
#include <iostream>

using namespace std;

int main() {

    // Question 1

    cout << "====================== Question 1 ======================" << endl;

    char prepared[100];
    prepare("Come to the Queen's Tower at 7 o'clock!", prepared);

    cout << "'Come to the Queen's Tower at 7 o'clock!' has been prepared for ";
    cout << "encoding as:" << endl;
    cout << "'" << prepared << "'." << endl << endl;

    // Question 2

    cout << "====================== Question 2 ======================" << endl;

    char playfair[6][6];
    grid("IMPERIAL", playfair);

    cout << "The encoding grid corresponding to the codeword 'IMPERIAL' is:"
         << endl;
    for (int row = 0; row < 6; row++) {
        for (int col = 0; col < 6; col++)
            cout << ((isalnum(playfair[row][col])) ? playfair[row][col] : '?')
                 << ' ';
        cout << endl;
    }
    cout << endl;

    // Question 3

    cout << "====================== Question 3 ======================" << endl;

    char out1, out2;
    bigram(playfair, 'C', 'O', out1, out2);

    cout << "The bigram 'CO' encodes as '" << out1 << out2 << "'" << endl;

    bigram(playfair, 'N', '9', out1, out2);

    cout << "The bigram 'N9' encodes as '" << out1 << out2 << "'" << endl
         << endl;

    // Question 4

    cout << "====================== Question 4 ======================" << endl;

    char encoded[100];
    encode(playfair, prepared, encoded);

    cout << "The string '" << prepared << "' encodes as:" << endl;
    cout << "'" << encoded << "'" << endl;

    // Bonus question

    cout << "==================== Bonus Question ====================" << endl;

    char decoded[100];
    decode(playfair, "VEKVPDQIQDEDEMMVEHSJPVHENOGMIRHVVMEG", decoded);

    cout << "The string 'VEKVPDQIQDEDEMMVEHSJPVHENOGMIRHVVMEG' decodes as:"
         << endl;
    cout << "'" << decoded << "'" << endl;

    return 0;
}