Tic-Tac-Toe

import random


board = [" " for _ in range(9)]


def print_board():
    for i in range(0, 9, 3):
        print(f"{board[i]} | {board[i+1]} | {board[i+2]}")
        if i < 6:
            print("-" * 9)


def check_win(board, player):
    winning_combinations = [(0, 1, 2), (3, 4, 5), (6, 7, 8),
                            (0, 3, 6), (1, 4, 7), (2, 5, 8),
                            (0, 4, 8), (2, 4, 6)]

    for a, b, c in winning_combinations:
        if board[a] == board[b] == board[c] == player:
            return True
    return False


def play_game():
    print("Welcome to Tic-Tac-Toe!")
    print_board()

    while True:
        
        move = int(input("Enter your move (1-9): ")) - 1
        if board[move] == " ":
            board[move] = "X"
        else:
            print("Invalid move. Try again.")
            continue

        print_board()

        
        if check_win(board, "X"):
            print("You win!")
            break

        
        if " " not in board:
            print("It's a tie!")
            break

        
        ai_move = random.choice([i for i, spot in enumerate(board) if spot == " "])
        board[ai_move] = "O"
        print(f"AI plays {ai_move + 1}:")
        print_board()

        
        if check_win(board, "O"):
            print("AI wins!")
            break


play_game()