'''
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]]
'''
class Solution:
    def permuteUnique(self, nums: List[int]) -> List[List[int]]:

        res = []
        self.dfs(nums, res, [])
        return res
        
    def dfs(self, nums, res, path):
        if not nums and path not in res:
            res.append(path)
        else:
            for i in range(len(nums)):
                self.dfs(nums[:i] + nums[i + 1:], res, path + [nums[i]])
