from typing import List


class Solution:
    def permuteUnique(self, nums: List[int]) -> List[List[int]]:
        def dfs(nums, size, depth, path, res, used):
            if depth == size:
                if path not in res:
                    res.append(path[:])
                return

            for i in range(size):
                if not used[i]:
                    used[i] = True
                    path.append(nums[i])

                    dfs(nums, size, depth + 1, path, res, used)

                    used[i] = False
                    path.pop()

        size = len(nums)
        if len(nums) == 0:
            return []

        used = [False for _ in range(size)]
        res = []

        dfs(nums, size, 0, [], res, used)

        return res

if __name__ == "__main__":
    nums = [1, 1, 3]
    solution = Solution()
    res = solution.permuteUnique(nums)
    print(res)