2215-find-the-difference-of-two-arrays.py

# Time Complexity: O(n), where n is the maximum length between nums1 and nums2.
# Space Complexity: O(m), where m is the length of the resulting difference lists.

from typing import List  # ignore this, just for typing


class Solution:
    def findDifference(self, nums1: List[int], nums2: List[int]) -> List[List[int]]:
        nums1_set = set(nums1)
        nums2_set = set(nums2)
        lst1 = [num for num in nums1_set if num not in nums2_set]
        lst2 = [num for num in nums2_set if num not in nums1_set]
        return [lst1, lst2]