题目：

题解：

class Solution:
    def maxProduct(self, words: List[str]) -> int:
        masks = defaultdict(int)
        for word in words:
            mask = reduce(lambda a, b: a | (1 << (ord(b) - ord('a'))), word, 0)
            masks[mask] = max(masks[mask], len(word))
        return max((masks[x] * masks[y] for x, y in product(masks, repeat=2) if x & y == 0), default=0)