Python实现奥赛罗(Reversi)游戏树生成功能报错求助

我需要编写一个不依赖任何库的Python函数，用于生成奥赛罗（Reversi）的游戏树，最终输出元组(a,b,c)：

• a：黑棋获胜局面数
• b：白棋获胜局面数
• c：平局局面数

给定的棋盘以TXT文件形式提供，示例棋盘如下：

. . W W
. . B B
W W W B
W B B W

但当前代码输出与预期不符：示例预期输出为(2, 16, 0)，实际得到(5, 7, 11)。以下是我的代码，无法定位错误，请求帮助排查。

def generate_game_tree(filename: str):
    
    # Load the board from the file
    board = [line.split() for line in open(filename)]

    # Initialize the game tree with the root node representing the current board state
    game_tree = [(board, 0)]
    black_count = 0
    white_count = 0
    draw_count = 0
    # Generate the game tree by expanding the nodes in a breadth-first manner
    i = 0
    while i < len(game_tree):
        node = game_tree[i]
        board, _ = node
        valid_moves = get_valid_moves(board)
        for move in valid_moves:
            new_board = make_move(board, move)
            game_tree.append((new_board, i))
        i += 1
    for i in range(len(board)):
        for j in range(len(board[0])):
            if board[i][j] == "W":
                white_count += 1
            if board[i][j] == "B":
                black_count += 1
            else:
                draw_count += 1
                 
    return black_count, white_count, draw_count


def make_move(board, move):
    flips = []
    x, y = move
    curr_color = board[x][y]
    for dx, dy in [(1, 0), (1, 1), (0, 1), (-1, 1), (-1, 0), (-1, -1), (0, -1), (1, -1)]:
        x, y = move
        x += dx
        y += dy
        if not (0 <= x < len(board) and 0 <= y < len(board[0])):
            continue
        if board[x][y] != '.':
            continue
        while board[x][y] != curr_color:
            flips.append((x, y))
            x += dx
            y += dy
            if not (0 <= x < len(board) and 0 <= y < len(board[0])):
                break
    return flips


def get_valid_moves(board):
    valid_moves = []
    for i in range(len(board)):
        for j in range(len(board[0])):
            if board[i][j] != '.':
                continue
            flips = make_move(board, (i, j))
            if flips:
                valid_moves.append((i, j))
    return valid_moves

内容的提问来源于stack exchange，提问作者Jake Sparrow