SubsetsII.py

# -*- coding: utf-8 -*-
# @File    : SubsetsII.py
# @Date    : 2020-01-10
# @Author  : tc
"""
题号 90 子集II
给定一个可能包含重复元素的整数数组 nums，返回该数组所有可能的子集（幂集）。

说明：解集不能包含重复的子集。

示例:

输入: [1,2,2]
输出:
[
  [2],
  [1],
  [1,2,2],
  [2,2],
  [1,2],
  []
]

参考:https://leetcode-cn.com/problems/subsets-ii/solution/hui-su-suan-fa-by-powcai-6/

"""
from typing import List

class Solution:
    def subsetsWithDup(self, nums: List[int]) -> List[List[int]]:
        res = []
        n = len(nums)
        nums.sort()

        def helper(idx, tmp):
            res.append(tmp)
            for i in range(idx, n):
                if i > idx and nums[i] == nums[i - 1]:
                    continue
                helper(i + 1, tmp + [nums[i]])

        helper(0, [])
        return res

if __name__ == '__main__':
    nums =  [1,2,2]
    solution = Solution()
    print(solution.subsetsWithDup(nums))