题目
Given an integer array nums of unique elements, return all possible subsets (the power set).
The solution set must not contain duplicate subsets. Return the solution in any order.
Example 1:
Input: nums = [1,2,3]
Output: [[],[1],[2],[1,2],[3],[1,3],[2,3],[1,2,3]]
Example 2:
Input: nums = [0]
Output: [[],[0]]
Constraints:
1 <= nums.length <= 10-10 <= nums[i] <= 10- All the numbers of
numsare unique.
思路
找出一个序列的所有子序列。设一个序列nums的有n个元素，那么可以得到如下公式：subsets(nums(n))=subsets(nums(n-1))+[subnet+[nums[n]] for subnet in subnets(n-1)]。如果此时有序列[1]，它的所有子序列为[[], [1]]，那么序列[1,2]的所有子序列则为[[], [1]]+[[]+[2], [1]+[2]]=[[], [1], [2], [1, 2]]，以此类推。
代码
python版本：
class Solution:
def subsets(self, nums: List[int]) -> List[List[int]]:
return reduce(lambda res, num: res+[i+[num] for i in res], nums, [[]])
