[C++] Casino Game

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
void roulette();
void blackjack();
void dice();

int main()
{
    int age;
    cout << "Welcome to the Casino!" << endl; // Welcomes User
    cout << "Please enter your age: " << endl; // Asks for Age
    cin >> age; // Age Input
    if (age < 21) // If less than 21, you cannot play.
    {
        cout << "Sorry, you are not old enough to gamble." << endl;
        return 0;
    }
    else if (age > 21) // If 21 or older, you can play.
    {
        int gameChoice; // Initalize gameChoice
        cout << "Thanks! What game would you like to play?" << endl; // Game Options
        cout << "1. Roulette" << endl;
        cout << "2. Blackjack" << endl;
        cout << "3. 7-11-Doubles" << endl;
        cin >> gameChoice; // Game Option Input
        if (gameChoice == 1) // Choice 1
        {
            roulette();
        }
        else if (gameChoice == 2) // Choice 2
        {
            blackjack();
        }
        else if (gameChoice == 3) // Choice 3
        {
            dice();
        }
    }
    return 0;
}

void roulette()
{
    double winnings; // Winnings Calculator
    int randomNumber; // The Board
    int x = 2, y = 1; // Odds and Events
    int betChoice; // Bet on Colors or Numbers?
    double betAmount; // How much to bet?
    cout << "How much would you like to bet?" << endl;
    cin >> betAmount;
    cout << "Do you want to bet on colors or numbers?" << endl;
    cout << "1. Colors" << endl;
    cout << "2. Numbers" << endl;
    cin >> betChoice;
    srand(time(0)); // Random Number Generator
    randomNumber = rand() % 36;
    if (betChoice == 1)
    {
        int betColor;
        cout << "What color would you like to bet on?" << endl;
        cout << "1. Black (Evens)" << endl;
        cout << "2. Red (Odds)" << endl;
        cout << "3. Green (0)" << endl;
        cin >> betColor;
        if (betColor == 1) // Black (evens)
        {
            while (x < 36)
            {
                if (x == randomNumber)
                {
                    cout << "You landed on Black! Your number was " << randomNumber << "." << endl;
                    winnings = betAmount * 2;
                    cout << "You're the lucky winner! You won $" << winnings << " USD." << endl;
                }
                x = x + 2;
            }
        }
        else if (betColor == 2) // Red (odds)
        {
            while (y < 36)
            {
                if (y == randomNumber)
                {
                    cout << "You landed on Red! Your number was " << randomNumber << "." << endl;
                    winnings = betAmount * 2;
                    cout << "You're today's lucky winner! You won $" << winnings << " USD." << endl;
                }
                y = y + 2;
            }
        }
        else if (betColor == 3) // Green (0)
        {
            if (randomNumber == 0)
            {
                cout << "You landed on Green! Your number was " << randomNumber << "." << endl;
                winnings = betAmount * 2;
                cout << "You're the lucky winner for today! You won $" << winnings << " USD." << endl;
            }
        }
    }
    else if (betChoice == 2) // Numbers
    {
        int betNumber;
        cout << "Please guess a number between 0 and 36: " << endl; // Please Guess Question
        cin >> betNumber;
        while (betNumber < 0 || betNumber > 36) // Keeps within 0 to 36 Range
        {
            cout << "Sorry, please choose a number between 0 and 36." << endl;
            cin >> betNumber;
        }
        if (betNumber == randomNumber)
        {
            cout << "You landed on " << randomNumber << "." << endl;
            winnings = betAmount * 35;
            cout << "Congratulations! You are the lucky winner! You won " << winnings << " USD." << endl;
        }
        else if (betNumber != randomNumber)
        {
            cout << "You landed on " << randomNumber << "." << endl;
            cout << "Sorry! You lost. :(" << endl;
        }
    }
}

void blackjack()
{
    double winnings; // Winnings Calculator
    int choice; // Player Choice
    int randomCard; // The Cards
    int playerSum = 0, dealerSum = 0; // Player & Dealer
    double betAmount; // Bet Amount
    cout << "How much would you like to bet?" << endl;
    cin >> betAmount;
    randomCard =  1 + rand() % 11; // Random Number Generator for Player
    playerSum = playerSum + randomCard; // Calculate Card
    randomCard = 1 + rand() % 11; // Random Number Generator for Player
    playerSum = playerSum + randomCard; // Calculate Card
    cout << "The Player's Hand: " << playerSum << endl;
    randomCard = 1 + rand() % 11; // Random Number Generator for Dealer
    dealerSum = dealerSum + randomCard; // Calculate Card
    randomCard = 1 + rand() % 11; // Random Number Generator for Dealer
    dealerSum = dealerSum + randomCard; // Calculate Card
    cout << "The Dealer's Hand: " << dealerSum << endl;
    winnings = betAmount * 2; // Winnings Multipler
    if (playerSum == 21)
    {
        cout << "You beat the dealer and have 21! You win: $" << winnings << endl;
    }
    else if (dealerSum == 21)
    {
        cout << "You lost to the dealer and they have 21. :(" << endl;
    }
    else
    {
        while (playerSum < 21)
        {
            if (dealerSum <= 17)
            {
                cout << "Dealer Hits" << endl;
                randomCard = 1 + rand() % 11;
                dealerSum = dealerSum + randomCard;
                cout << "The Dealer's Hand: " << dealerSum << endl;
                if (dealerSum > 21)
                {
                    cout << "You beat the dealer. They exceeded 21." << endl;
                }
            }
            else if (dealerSum >= 17)
            {
                cout << "The Dealer Stays" << endl;
            }
            else if (dealerSum < 21)
            {
                cout << "The Dealer Stays" << endl;
            }
            cout << "What would you like to do?" << endl; // Option
            cout << "1. Hit" << endl; // Hit
            cout << "2. Stay" << endl; // Stay
            cin >> choice;
            if (choice == 1) // Option 1 - Hit
            {
                randomCard = 1 + rand() % 12; // Random Number Generator
                playerSum = playerSum + randomCard; // Calculate Cards
                cout << "The Player's Hand: " << playerSum << endl;
                if (playerSum > 21)
                {
                    cout << "You lost to the dealer. You exceeded 21." << endl;
                }
            }
            else if (choice == 2) // Option 2 - Stay
            {
                if (dealerSum < playerSum)
                {
                    cout << "You beat the dealer and won! You win: $" << winnings << endl;
                }
                else if (dealerSum > playerSum)
                {
                    cout << "The Dealer Wins! You lost :(" << endl;
                }
            }
        }
    }
}

void dice()
{
    double winnings; // Winnings Calculator
    int randomNumber1, randomNumber2; // Dice 1 and Dice 2
    double betAmount; // Bet Amount
    cout << "How much would you like to bet?" << endl;
    cin >> betAmount;
    randomNumber1 = rand() % 6 + 1; // Dice 1
    randomNumber2 = rand() % 6 + 1; // Dice 2
    cout << "Your first dice was a " << randomNumber1 << "." << endl;
    cout << "Your second dice was a " << randomNumber2 << "." << endl;
    if(randomNumber1 + randomNumber2 == 7) // If 7, win!
    {
        cout << "Congrautlations! You won!" << endl;
        winnings = betAmount * 2;
        cout << "You won: " << winnings << " USD" << endl;
    }
    else if (randomNumber1 + randomNumber2 == 11) // If 11, win!
    {
        cout << "Congrautlations! You won!" << endl;
        winnings = betAmount * 2;
        cout << "You won: " << winnings << " USD" << endl;
    }
    else if (randomNumber1 == randomNumber2) // If Dice 1 = Dice 2, win!
    {
        cout << "Congrautlations! You won!" << endl;
        winnings = betAmount * 2;
        cout << "You won: " << winnings << " USD" << endl;
    }
    else if (randomNumber1 != randomNumber2) // Anything else, lose :(
    {
        cout << "Sorry! You lost :(" << endl;
    }
}