[LeetCode]题解（python）：078 Subsets

题目来源

Given a set of distinct integers, nums, return all possible subsets.

Note:

• Elements in a subset must be in non-descending order.
• The solution set must not contain duplicate subsets.

:type nums: List[int]

Output:

:rtype: List[List[int]]

Conditions: 给定一个没有重复元素的list，返回其所有的子集，注意每一个子集中的元素都是非降序的，子集不可以重复。

 1 class Solution(object):
 2     def subsets(self, nums):
 3         """
 4         :type nums: List[int]
 5         :rtype: List[List[int]]
 6         """
 7         def dfs(depth, start, valueList):
 8             res.append(valueList)
 9             if depth == len(nums):
10                 return
11             for i in range(start, len(nums)):
12                 dfs(depth + 1, i + 1, valueList+[nums[i]])
13
14         nums.sort()
15         res = []
16         dfs(0, 0, [])
17         return res