def moves_to_nested_dict(moves: list[list[str]]) -> dict[tuple[str, int], dict]:
    """
    Convert <games> into a nested dictionary representing the sequence of moves
    made in the games.

    Each list in <games> corresponds to one game, with the i'th str being the
    i'th move of the game.

    The nested dictionary's keys are tuples containing the string representing
    the move made on that turn and an integer indicating how many games ended
    immediately after this move. See the docstring example below.

    The values of each nested dictionary are themselves nested dictionaries of
    this structure. An empty dictionary is stored as the value for a move that
    will correspond to a leaf

    Note: to keep the docstring short, we use single letters in place
          of real chess moves, as it has no impact on the logic of how this
          code needs to be implemented, since it should work for arbitary
          strings used to denote moves.

    >>> moves_to_nested_dict([[]])  # empty lists are ignored
    {}
    >>> moves_to_nested_dict([])
    {}
    >>> moves_to_nested_dict([['a'], []])
    {('a', 1): {}}
    >>> d = moves_to_nested_dict([["a", "b", "c"],
    ...                           ["a", "b"], ["d", "e"], ["d", "e"]])
    >>> d
    {('a', 0): {('b', 1): {('c', 1): {}}}, ('d', 0): {('e', 2): {}}}
    >>> d = moves_to_nested_dict([
    ...    ["a", "b", "c"], ["a", "b"], ["d", "e", "a"], ["d", "e"]])
    >>> d
    {('a', 0): {('b', 1): {('c', 1): {}}}, ('d', 0): {('e', 1): {('a', 1): {}}}}
    """

我一直在尝试解决这个函数，但我有点卡住了。我知道如何写一般结构，但不知道如何正确地得到数字。有人可以帮助实现吗
这就是我所做的

result = {}
for game_moves in moves:
    if len(game_moves) == 0:
        continue
    current_dict = result
    num_ended_games = 0
    for move in game_moves[:-1]:
        key = (move, num_ended_games)
        if key not in current_dict:
            current_dict[key] = {}
        current_dict = current_dict[key]
        num_ended_games = 0
    last_move = game_moves[-1]
    key = (last_move, num_ended_games)
    if key not in current_dict:
        current_dict[key] = {}
    current_dict = current_dict[key]
    num_ended_games += 1
return result

错误消息为

失败示例：d
预期：

{('a', 0): {('b', 1): {('c', 1): {}}}, ('d', 0): {('e', 2): {}}}

得到：

{('a', 0): {('b', 0): {('c', 0): {}}}, ('d', 0): {('e', 0): {}}}