Leetcode 350. Intersection of Two Arrays II

Problem

Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must appear as many times as it shows in both arrays and you may return the result in any order.

Algorithm

Collect all the elements in each list in two conut list and then return the min size items appear in both conut list.

Code

class Solution:
    def intersect(self, nums1: List[int], nums2: List[int]) -> List[int]:
        item1 = [0] * 1001
        item2 = [0] * 1001
        for i in nums1:
            item1[i] += 1
        for i in nums2:
            item2[i] += 1

        ans = []
        for i in range(1001):
            if item1[i] and item2[i]:
                ans += [i] * min(item1[i], item2[i])
        return ans