Noughts & Crosses

#include <iostream>
#include <string>
#include <map>
#include <random>
#include <ctime>
#include <cstdlib>

//This function shows the current grid and where the noughts and crosses are on the board.
void displayGrid(int GRID[3][3], std::map<int, char>& playerPositions)
{
    for (int i = 0; i < 3; i++)
    {
        for (int x = 0; x < 3; x++)
        {
            std::string outputValue = std::to_string(GRID[i][x]);
            if (playerPositions.count(GRID[i][x])) outputValue = playerPositions[GRID[i][x]];
            std::cout << outputValue << " ";
        }

        std::cout << "\n";
    }
    std::cout << "\n";
}

//Automagically make the next move.
int autoMove(std::map<int, char>& playerPositions)
{
    std::srand(std::time(0));
    unsigned int randNum = 0;

    do { randNum = rand() % 9 + 1;;
    } while (playerPositions.count(randNum) && randNum != 0);
    return randNum;
}

//This enables the user to make their move and ensures that the position has not been already taken.
void playMove(std::map<int, char>& playerPositions, const char player)
{
    int userInput = 0;

    do {
        std::cout << "[ " << player << " ] player, please make your move: ";
        std::cin >> userInput;

        //If the user enters 0, make the move for them.
        if (userInput == 0)
            userInput = autoMove(playerPositions);

    } while (playerPositions.count(userInput) && userInput != 0);

    playerPositions.insert({ userInput, player });
}

//This function checks if a player has one the game.
std::string checkForWin(int GRID[3][3], std::map<int, char>& playerPositions)
{
    //This changes the grid array into a string array so it can compare against the player variable later in the function.
    std::string cGRID[3][3];
    for (int i = 0; i < 3; i++)
    {
        for (int x = 0; x < 3; x++)
        {
            if (playerPositions.count(GRID[i][x])) cGRID[i][x] = playerPositions[GRID[i][x]];
            else cGRID[i][x] = std::to_string(GRID[i][x]);
        }
    }

    for (int i = 0; i < 2; i++)
    {
        std::string player = "O";
        if (i == 1)
            player = "X";

        if (cGRID[0][0] == player && cGRID[0][1] == player && cGRID[0][2] == player) return player;
        else if (cGRID[1][0] == player && cGRID[1][1] == player && cGRID[1][2] == player) return player;
        else if (cGRID[2][0] == player && cGRID[2][1] == player && cGRID[2][2] == player) return player;
        else if (cGRID[0][0] == player && cGRID[1][0] == player && cGRID[2][0] == player) return player;
        else if (cGRID[0][1] == player && cGRID[1][1] == player && cGRID[2][1] == player) return player;
        else if (cGRID[0][2] == player && cGRID[1][2] == player && cGRID[2][2] == player) return player;
        else if (cGRID[0][0] == player && cGRID[1][1] == player && cGRID[2][2] == player) return player;
        else if (cGRID[0][2] == player && cGRID[1][1] == player && cGRID[2][0] == player) return player;
    }

    return "";
}

//This function announces the winner of the game.
void announceWinner(int GRID[3][3], std::map<int, char>& playerPositions, const char winner)
{
    system("cls");
    displayGrid(GRID, playerPositions);
    std::cout << "\n\n" << winner << " Wins the Game!\n\n";
}

int main()
{
    //Initializes the grid array and the map to store the player positions.
    int GRID[3][3] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } };
    std::map<int, char> playerPositions;

    //Gives the player 9 moves in total.
    for (int i = 0; i < 9; i++)
    {
        system("cls");
        displayGrid(GRID, playerPositions);

        //Oscillates between the nought player and the cross player.
        char player = 'X';
        if (i % 2) player = 'O';

        playMove(playerPositions, player);

        //Check if anyone has won the game.
        char winStatus = checkForWin(GRID, playerPositions)[0];
        if (winStatus == 'X' || winStatus == 'O')
        {
            announceWinner(GRID, playerPositions, winStatus);
            return 0;
        }
    }
    std::cout << "\n\nEveryone is a winner!";
}