C#: faster than 85%
Intuition\nUse HashSet and its methods.\n\n# Approach\nUse HashSet and its method ExceptWith to except items from the other array.\n\n# Complexity\n- Time compl
# Intuition\nUse HashSet<int> and its methods.\n\n# Approach\nUse HashSet<int> and its method ExceptWith to except items from the other array.\n\n# Complexity\n- Time complexity:\n$$O(n)$$\n\n- Space complexity:\n$$O(n)$$\n\n# Code\n```\npublic class Solution {\n    public IList<IList<int>> FindDifference(int[] nums1, int[] nums2) {\n        var set1 = new HashSet<int>(nums1);\n        var set2 = new HashSet<int>(nums2);\n        set2.ExceptWith(nums1);\n        set1.ExceptWith(nums2);\n        return new List<IList<int>>{set1.ToList(), set2.ToList()};\n    }\n}\n```
['Hash Table', 'C#']