Guess My Number

/*************************************************************************************************
*  Program Name: Guess My Number Game                                                           *
*  Author:       Terry Weiss                                                                    *
*  Date Written: 1/12/2016                                                                      *
*************************************************************************************************
*    This program runs the classic number guessing game. The computer guesses a number between  *
*  1 and 100, and the player must then guess that number. The computer will tell the player if  *
*  the guess is high or low, or if it's correct. The player may also decide to choose a number  *
*  and have the computer try to guess it.
*************************************************************************************************/

#include <cstdlib>
#include <ctime>
#include <iostream>



enum mainOption { GUESSER = 1, CHOOSER_DUMB, CHOOSER_SMART, EXIT };


const int MIN_GUESS = 1;
const int MAX_GUESS = 100;
const std::string PLAY_AGAIN_MSG = "\nThat was fun! Let's play again!\n";


mainOption mainMenu();
void playGuesser();
void playChooser(bool smart);



int main() {
    std::srand(static_cast<unsigned int>(time(0)));

    mainOption option;
    do {
        option = mainMenu();

        switch (option) {
        case GUESSER:
            playGuesser();
            break;
        case CHOOSER_DUMB:
            playChooser(false);
            break;
        case CHOOSER_SMART:
            playChooser(true);
            break;
        case EXIT:
            std::cout << "We should do this again some time!\n\n";
            break;
        default:
            std::cout << "**ERROR**: Invalid menu option  {" << option << "}\n\n";
        }
    } while (option != EXIT);

    return EXIT_SUCCESS;
}



mainOption mainMenu() {
    mainOption option;


    std::cout << "  1. Play as guesser\n"
              << "  2. Play as chooser\n"
              << "  3. Play as chooser (against smartest guesses)\n"
              << "  4. Exit\n";

    do {
        std::cout << "Please choose a game mode to begin: ";
        std::cin >> option;

        if (option < 1 || option > EXIT) {
            std::cout << "Invalid option. ";
        }
    } while (option < 1 || option > EXIT);


    return option;
}


void playGuesser() {
    int number = (std::rand() % (MAX_GUESS - MIN_GUESS + 1)) + MIN_GUESS;
    int guess, guesses = 0;

    std::cout << "\nOkay, I'm ready!" << std::endl;

    do { //Repeat until number is guessed correctly
        std::cout << "Please pick an integer between " << MIN_GUESS << " and " << MAX_GUESS << ": ";
        std::cin >> guess;

        if (guess < MIN_GUESS || guess > MAX_GUESS) {
            std::cout << "Sorry, invalid guess. ";
        }
        else {
            guesses++;

            if (guess < number) {
                std::cout << "No, that's too low." << std::endl;
            }
            else if (guess > number) {
                std::cout << "Sorry, that's too high." << std::endl;
            }
            else {
                std::cout << "Congrats, you got it!! It only took " << guesses << " guess"
                    << ((guesses == 1) ? "" : "es") << "." << std::endl; //pluralize "guesses"
            }
        }
    } while (guess != number);

    std::cout << PLAY_AGAIN_MSG;
}

void playChooser(bool smart) {
    enum resultOption { HIGH = 1, LOW, CORRECT };

    int guess, guesses = 0;
    int min, max;
    resultOption result;
    bool cheater = false;



    std::cout << "\nAlrighty, pick a number between " << MIN_GUESS << " and " << MAX_GUESS
        << " but don't tell me!" << std::endl
        << "Hit any key when you're ready..." << std::endl;
    std::cin.get();


    min = MIN_GUESS;
    max = MAX_GUESS;
    do { //until the guess is right or it's determined the player is cheating
        if (smart) {
            guess = (max - min) / 2;
        }
        else {
            guess = std::rand() % (max - min + 1) + min;
        }

        std::cout << "  1. Too high" << std::endl
            << "  2. Too low" << std::endl
            << "  3. Correct!" << std::endl;
        do {
            std::cout << "Is it " << guess << "? ";
            std::cin >> result;

            if (result < HIGH || result > CORRECT) {
                std::cout << "Invalid option. ";
            }
        } while (result < HIGH || result > CORRECT);

        if (result == CORRECT) {
            std::cout << "Awesome! I got it right in " << guesses << " guesses." << std::endl;
        }
        else if (result == HIGH || result == LOW) {
            if (max == min) { //If it's the only option left, it can't be wrong.
                cheater = true;
            }
            else if (result == HIGH) {
                if (guess == min) { //It can't be lower than the min.
                    cheater = true;
                }
                else {
                    max = guess - 1;
                }
            }
            else if (result == LOW) {
                if (guess == max) { //It can't be higher than the max.
                    cheater = true;
                }
                else {
                    min = guess + 1;
                }
            }

            if (cheater) {
                std::cout << "Hmm, it seems like someone likes to cheat ;)" << std::endl
                    << "You had me going there for " << guesses << "guesses." << std::endl;
            }
        }
        else {
            std::cout << "**ERROR**: Invalid result. {" << result << "}" << std::endl;
        }

    } while (result != CORRECT && !cheater);


    std::cout << PLAY_AGAIN_MSG;
}