Subsets

Given two sorted integer arrays A and B, merge B into A as one sorted array.
Note: You may assume that A has enough space to hold additional elements from B. The number of
elements initialized in A and B are m and n respectively.
Given a set of distinct integers, S, 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 S = [1,2,3], a solution is:
[
[3],
[1],
[2],
[1,2,3],
[1,3],
[2,3],
[1,2],
[]
]