Solution
from collections import Counter
from typing import List
class Solution:
def intersect(self, nums1: List[int], nums2: List[int]) -> List[int]:
cnt = Counter(nums1)
ans = []
for x in nums2:
if cnt[x]:
ans.append(x)
cnt[x] -= 1
return ans
# 本地测试
if __name__ == "__main__":
sol = Solution()
print(sol.intersect([1,2,2,1], [2,2])) # [2, 2]
print(sol.intersect([4,9,5], [9,4,9,8,4])) # [4,9]
print(sol.intersect([1,2,3], [])) # []