349.Intersection of Two Arrays

Tags: [set]

Link: https://leetcode.com/problems/intersection-of-two-arrays/\#/description

Given two arrays, write a function to compute their intersection.

Example:
Givennums1=[1, 2, 2, 1],nums2=[2, 2], return[2].

Note:

• Each element in the result must be unique.
• The result can be in any order.

Solution: set

class Solution(object):
    def intersection(self, nums1, nums2):
        """
        :type nums1: List[int]
        :type nums2: List[int]
        :rtype: List[int]
        """
        if not nums1 or not nums2:
            return []

        nums1_set = set(nums1)
        result_set = set()
        for num in nums2:
            if num in nums1_set:
                result_set.add(num)

        return [x for x in result_set]

Note:

• Time complexity = O(n + k), n is the length of nums1, and k is the length of nums2.