Tic Tac Toe游戏的问题

def check_winner(board):
    # 检查所有行、列和对角线
    for i in range(3):
        if board[i][0] == board[i][1] == board[i][2] != ' ':
            return True
        if board[0][i] == board[1][i] == board[2][i] != ' ':
            return True
    if board[0][0] == board[1][1] == board[2][2] != ' ':
        return True
    if board[0][2] == board[1][1] == board[2][0] != ' ':
        return True
    return False

def is_full(board):
    for row in board:
        if ' ' in row:
            return False
    return True

def game_over(board):
    return check_winner(board) or is_full(board)

def minimax(board, depth, is_maximizing):
    if check_winner(board):
        return -1 if is_maximizing else 1
    if is_full(board):
        return 0
    
    if is_maximizing:
        best_score = -float('inf')
        for i in range(3):
            for j in range(3):
                if board[i][j] == ' ':
                    board[i][j] = 'O'
                    score = minimax(board, depth + 1, False)
                    board[i][j] = ' '
                    best_score = max(score, best_score)
        return best_score
    else:
        best_score = float('inf')
        for i in range(3):
            for j in range(3):
                if board[i][j] == ' ':
                    board[i][j] = 'X'
                    score = minimax(board, depth + 1, True)
                    board[i][j] = ' '
                    best_score = min(score, best_score)
        return best_score

def find_best_move(board):
    best_move = None
    best_score = -float('inf')
    for i in range(3):
        for j in range(3):
            if board[i][j] == ' ':
                board[i][j] = 'O'
                score = minimax(board, 0, False)
                board[i][j] = ' '
                if score > best_score:
                    best_score = score
                    best_move = (i, j)
    return best_move