47\. Permutations II

Medium

Given a collection of numbers, `nums`, that might contain duplicates, return _all possible unique permutations **in any order**._

**Example 1:**

**Input:** nums = [1,1,2]

**Output:** [[1,1,2], [1,2,1], [2,1,1]] 

**Example 2:**

**Input:** nums = [1,2,3]

**Output:** [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]] 

**Constraints:**

*   `1 <= nums.length <= 8`
*   `-10 <= nums[i] <= 10`