Tic-Tac-Toe in C++

#include <iostream>
#include <vector>

using namespace std;

// Function to print the Tic-Tac-Toe board
void printBoard(const vector<vector<char>>& board) {
    for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 3; ++j) {
            cout << board[i][j];
            if (j < 2) cout << " | ";
        }
        cout << endl;
        if (i < 2) cout << "---------" << endl;
    }
    cout << endl;
}

// Function to check if there's a winner
char checkWinner(const vector<vector<char>>& board) {
    // Check rows
    for (int i = 0; i < 3; ++i) {
        if (board[i][0] == board[i][1] && board[i][1] == board[i][2]) {
            return board[i][0];
        }
    }

    // Check columns
    for (int j = 0; j < 3; ++j) {
        if (board[0][j] == board[1][j] && board[1][j] == board[2][j]) {
            return board[0][j];
        }
    }

    // Check diagonals
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2]) {
        return board[0][0];
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0]) {
        return board[0][2];
    }

    return ' '; // No winner yet
}

int main() {
    vector<vector<char>> board(3, vector<char>(3, ' '));
    char currentPlayer = 'X';
    int row, col;

    cout << "Tic-Tac-Toe Game" << endl;
    printBoard(board);

    int moves = 0;
    while (true) {
        cout << "Player " << currentPlayer << ", enter row (0-2) and column (0-2): ";
        cin >> row >> col;

        if (row < 0 || row > 2 || col < 0 || col > 2 || board[row][col] != ' ') {
            cout << "Invalid move! Try again." << endl;
            continue;
        }

        board[row][col] = currentPlayer;
        printBoard(board);

        char winner = checkWinner(board);
        if (winner != ' ') {
            cout << "Player " << winner << " wins!" << endl;
            break;
        }

        if (++moves == 9) {
            cout << "It's a draw!" << endl;
            break;
        }

        currentPlayer = (currentPlayer == 'X') ? 'O' : 'X';
    }

    return 0;
}