递归数独解谜错误

如何解决递归数独解谜错误

我正在编写一个数独谜题求解器，它将列表列表作为“谜题”，每个列表代表谜题中的一行。我创建了一个包含多个函数来处理谜题的脚本，但是当我尝试解决谜题时遇到了递归错误。我相信 solve() 函数存在问题，但 get_question() 函数也可能存在问题，尤其是我处理列的方式。如果需要，我可以附加其他功能。

'''

def get_options(puzzle,row,col):
    if puzzle[row][col] > 0:
        return None
    used = []
    for item in puzzle[row]:
        if item != 0:
            used.append(item)
    for i in range(len(puzzle)):
        if puzzle[i][col] != 0:
            used.append(item)
    start_row = 3 * int(row / 3)
    start_col = 3 * int(col / 3)
    for x in range(3):
        if puzzle[start_row + x] != 0:
            used.append(puzzle[start_row + x])
        for i in range(3):
            if puzzle[start_row + x][start_col + i] != 0:
                used.append(puzzle[start_row + x][start_col + i])
    options = []
    for i in range(10):
        if i not in used:
            options.append(i)
    return options

def solve(puzzle,row=0,col=0):
    if puzzle[row][col] > 0:
        next_row,next_col = get_next(row,col)
        if next_row is None:
            return puzzle
        # issue here
        else:
            solve(puzzle,next_row,next_col)
    else:
        options = get_options(puzzle,col)
        if not options:
            return None
        else:
            for opt in options:
                new_puzzle = copy_puzzle(puzzle)
                new_puzzle[row][col] = opt
                # issue here
                result = solve(new_puzzle)
            if result is not None:
                return result

'''