[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:

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):
return
for i in range(start, len(nums)):
dfs(depth + 1, i + 1, valuelist + [nums[i]])

nums.sort()
ans = []
dfs(0, 0, [])
return ans