为Tic Tac Toe打造平局游戏功能

Question

I am making a tic tac toe game, and so far there is complete functionality except for a tie game instance. The program doesnt end when there isnt a winner. I am not sure how to approach this, maybe I should add to my champion function, or make a completely new function. Some suggestions would be great. Im a beginner so any criticism is greatly appreciated.

    #define GRID_SIZE 3

    class TicTacToe {
    private:
    char map[GRID_SIZE][GRID_SIZE];

    public:


    void computers_turn() {
        while (true) {
            int choice = (rand() % 9) + 1;

            int row = choice / 3;
            int col = choice % 3;
            char grid_position = map[row][col];

            if (grid_position == 'X' || grid_position == 'O') {
                std::cout << "Space taken. Try again" << std::endl;
            } else {
                map[row][col] = (char) 'O';
                break;
            }

        }


    }

    // determines any winning combination, horizontal, diagonal, 
    //vertical
    void champion() {
        const char *possiblities[8]{
                "123",
                "456",
                "789",
                "147",
                "159",
                "258",
                "369",
                "753"
        };

        for (int i = 0; i < 8; i++) {

            char previous_pos = '0';
            const char *possible_moves = possiblities[i];
            bool winner = true;


            for (int index = 0; index < GRID_SIZE; index++) {
                char character = possible_moves[index];
                int entered_num = character - '0';
                int grid_space = entered_num - 1;

                int row = grid_space / GRID_SIZE;
                int col = grid_space % GRID_SIZE;

                char grid_coordinate = map[row][col];


                if (previous_pos == '0') {
                    previous_pos = grid_coordinate;
                } else if
                        (previous_pos == grid_coordinate) {
                    continue;
                } else {
                    winner = false;
                    break;
                }
            }
            if (winner) {
                puts("You win");
                exit(0);


            }

        }


    }

    // initializes game, asks user for input
    void playgame() {
        std::string input;

        while (true) {
            std::cout << "Go player one" << std::endl;
            getline(std::cin, input);
            if (input != " ") {
                char entered = input.c_str()[0];

                if (entered >= '1' && entered <= '9') {
                    int entered_num = entered - '0';
                    int index = entered_num - 1;
                    int row = index / 3;
                    int col = index % 3;
                    char grid_position = map[row][col];

                    if (grid_position == 'X' || grid_position == 'O') {
                        std::cout << "Space taken. Try again" << std::endl;
                    } else {
                        map[row][col] = (char) 'X';
                        break;
                    }

                } else {
                    std::cout << "Only numbers 1 - 9" << std::endl;
                }
            } else {
                std::cout << "Have to enter something, try again" << std::endl;
            }


        }
    }

    // generates tic tac toe grid
    void generateGrid() {
        int number = 1;

        for (int x = 0; x < GRID_SIZE; x++) {
            for (int y = 0; y < GRID_SIZE; y++) {
                map[x][y] = std::to_string(number).c_str()[0];
                number += 1;
            }
        }
    }

    // displays updated tic tac toe grid
    void tictacToeMap() {


        std::cout << std::endl;

        for (int x = 0; x < GRID_SIZE; x++) {
            for (int y = 0; y < GRID_SIZE; y++) {
                std::printf(" %c ", map[x][y]);
            }
            std::cout << std::endl;
        }

    }


    TicTacToe() {
        generateGrid();
        while (true) {
            champion();
            tictacToeMap();
            playgame();
            computers_turn();


        }
    }
    };


    int main() {

    TicTacToe tic;
    tic.playgame();


    return 0;

Answer 1

You could initialize all the spaces in the grid to '' , then after each turn you could call a function to check if the game is a tie. The function could have a for loop inside of a for loop that just checks if all the grids have a value not equal to ''

Here is a sample function:

bool IsGameOver(char map[][])
{
    bool answer = true;
    for (int i=0;i<3;i++)
    {
       for (int j=0;j<3;j++)
       {
          char grid_pos = map[i][j];
          if (grid_pos=='')
             answer = false;
       }
    }

    return answer;
}

Just implement something like this