[Leetcode]@python 90. Subsets II.py

题目链接

https://leetcode.com/problems/subsets-ii/

题目原文

Given a collection of integers that might contain duplicates, nums, return all possible subsets.

Note:
Elements in a subset must be in non-descending order.
The solution set must not contain duplicate subsets.
For example,
If nums = [1,2,2], a solution is:

[
[2],
[1],
[1,2,2],
[2,2],
[1,2],
[]]

题目大意

给出一个有重复元素的所有集合的子集的list

解题思路

使用dfs进行求解

代码

class Solution(object):def subsetsWithDup(self, nums):""":type nums: List[int]:rtype: List[List[int]]"""def dfs(depth, start, valuelist):if valuelist not in ans:ans.append(valuelist)if depth == len(nums):returnfor i in range(start, len(nums)):dfs(depth + 1, i + 1, valuelist + [nums[i]])nums.sort()ans = []dfs(0, 0, [])return ans