[Python3] Simple solution using set
\n    def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:\n        s1 = set(nums1)\n        s2 = set(nums2)\n        \n        nums
\n    def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:\n        s1 = set(nums1)\n        s2 = set(nums2)\n        \n        nums1 = list(s1)\n        nums2 = list(s2)\n        \n        s = []\n        for i in range(len(nums1)):\n            if nums1[i] not in s2:\n                s.append(nums1[i])\n        d = []   \n        for i in range(len(nums2)):\n            if nums2[i] not in s1:\n                d.append(nums2[i])\n                \n        res = []\n        res.append(s)\n        res.append(d)\n        return res
['Ordered Set', 'Python', 'Python3']