Intersection of Two Arrays

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

Example: Given nums1 = [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.

class Solution(object):
    def intersection(self, nums1, nums2):
        """
        :type nums1: List[int]
        :type nums2: List[int]
        :rtype: List[int]
        """
        res = []
        for n in nums1:
            if n in nums2 and n not in res:
                res += n,
        return res

A bit faster

class Solution(object):
    def intersection(self, nums1, nums2):
        """
        :type nums1: List[int]
        :type nums2: List[int]
        :rtype: List[int]
        """
        res = {}
        val = []
        for n in nums1:
            res[n] = 1
        for n in nums2:
            if n in res:
                res[n] += 1
        for k,v in res.items():
            if v > 1:
                val += k,
        return val