using System;

​

class Game_X_O

{

    private char[] board;

    private char currentPlayer;

​

    public Game_X_O()

    {

        board = new char[9];

        currentPlayer = 'X';

        InitializeBoard();

    }

​

    private void InitializeBoard()

    {

        for (int i = 0; i < board.Length; i++)

        {

            board[i] = ' ';

        }

    }

​

    private void DisplayBoard()

    {

        Console.WriteLine($" _____ _____ _____ ");

        Console.WriteLine($"|     |     |     |");

        Console.WriteLine($"|  {board[0]}  |  {board[1]}  |  {board[2]}  |");

        Console.WriteLine($"|_____|_____|_____| ");

        Console.WriteLine($"|     |     |     | ");

        Console.WriteLine($"|  {board[3]}  |  {board[4]}  |  {board[5]}  |");

        Console.WriteLine($"|_____|_____|_____| ");

        Console.WriteLine($"|     |     |     | ");

        Console.WriteLine($"|  {board[6]}  |  {board[7]}  |  {board[8]}  |");

        Console.WriteLine($"|_____|_____|_____| ");

    }

    public void PlayGame()

    {

        int move;

        bool validMove;

        bool gameOver = false;

​

        do

        {

            DisplayBoard();

​

            do

            {

                Console.Write($"Player {currentPlayer}, select position (1-9): ");

                validMove = int.TryParse(Console.ReadLine(), out move) && move >= 1 && move <= 9 && board[move - 1] == ' ';

                if (!validMove)

                {

                    Console.WriteLine("Wrong position! Try again!");

                }

            } while (!validMove);

​

            board[move - 1] = currentPlayer;

            gameOver = CheckForWin() || CheckForTie();

​

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

​

        } while (!gameOver);

​

        DisplayResult();

    }

​

    private bool CheckForWin()

    {

        // сheck horizontal, vertical lines and diagonals

        return (board[0] == board[1] && board[1] == board[2] && board[0] != ' ') ||

               (board[3] == board[4] && board[4] == board[5] && board[3] != ' ') ||

               (board[6] == board[7] && board[7] == board[8] && board[6] != ' ') ||

               (board[0] == board[3] && board[3] == board[6] && board[0] != ' ') ||

               (board[1] == board[4] && board[4] == board[7] && board[1] != ' ') ||

               (board[2] == board[5] && board[5] == board[8] && board[2] != ' ') ||

               (board[0] == board[4] && board[4] == board[8] && board[0] != ' ') ||

               (board[2] == board[4] && board[4] == board[6] && board[2] != ' ');

    }

​

    private bool CheckForTie()

    {

        // check draw

        foreach (char cell in board)

        {

            if (cell == ' ')

            {

                return false; 

            }

        }

        return true; 

    }

​

​

    private void DisplayResult()

    {

        DisplayBoard();

​

        if (CheckForWin())

        {

            if (currentPlayer == 'X') 

            {

            Console.WriteLine($"Player O has won!");

            }

            else

            {

            Console.WriteLine($"Player X has won!");

            }

        }

        else

        {

            Console.WriteLine("The game end! It is draw!");

        }

    }

}

​

class Program

{

    static void Main(string[] args)

    {

        Game_X_O game = new Game_X_O();

        game.PlayGame();

    }

}

​