卧槽，用二进制，绝了

from functools import reduce


class Solution:
    def subsetsWithDup(self, S):
        # write your code here
        S.sort()
        p = [[S[x] for x in range(len(S)) if i>>x&1] for i in range(2**len(S))]
        func = lambda x,y:x if y in x else x + [y]
        p = reduce(func, [[], ] + p)
        print(len(p))
        return list((p))