Subsets II

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],
[]
]

利用DFS，深度查找法来解决此题,,,,

调用一个函数一直往下找找到最后返回。

返回后添加元素

安安