Вот базовая реализация крестиков-ноликов на C++:

#include <iostream>
#include <vector>
using namespace std;
// Function to display the Tic Tac Toe board
void displayBoard(const vector<vector<char>>& board) {
    for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 3; ++j) {
            cout << board[i][j] << " ";
        }
        cout << endl;
    }
}
// Function to check if a player has won
bool checkWin(const vector<vector<char>>& board, char player) {
    // Check rows
    for (int i = 0; i < 3; ++i) {
        if (board[i][0] == player && board[i][1] == player && board[i][2] == player)
            return true;
    }
// Check columns
    for (int i = 0; i < 3; ++i) {
        if (board[0][i] == player && board[1][i] == player && board[2][i] == player)
            return true;
    }
// Check diagonals
    if (board[0][0] == player && board[1][1] == player && board[2][2] == player)
        return true;
    if (board[0][2] == player && board[1][1] == player && board[2][0] == player)
        return true;
    return false;
}
// Function to play the game
void playGame() {
    vector<vector<char>> board(3, vector<char>(3, '-'));
    char currentPlayer = 'X';
    bool isGameOver = false;
    while (!isGameOver) {
        displayBoard(board);
        int row, col;
        cout << "Player " << currentPlayer << ", enter your move (row and column): ";
        cin >> row >> col;
        if (row < 0 || row >= 3 || col < 0 || col >= 3 || board[row][col] != '-') {
            cout << "Invalid move. Try again!" << endl;
            continue;
        }
        board[row][col] = currentPlayer;
        if (checkWin(board, currentPlayer)) {
            cout << "Player " << currentPlayer << " wins!" << endl;
            isGameOver = true;
        } else if (currentPlayer == 'X') {
            currentPlayer = 'O';
        } else {
            currentPlayer = 'X';
        }
    }
    displayBoard(board);
}
int main() {
    playGame();
    return 0;
}

Этот код позволяет двум игрокам играть в крестики-нолики на консоли. Он использует 2D-вектор для представления игрового поля и реализует функции для отображения поля, проверки выигрыша и ведения игры.