[LeetCode][Python]Intersection of Two Arrays

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.

https://leetcode.com/problems/intersection-of-two-arrays/

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求两个数组的交集。

先遍历nums1，第一个哈希表记录所有nums1中出现过的元素。

再遍历nums2，第二个哈希表记录已经在结果中的元素。

class Solution(object):
    def intersection(self, nums1, nums2):
        """
        :type nums1: List[int]
        :type nums2: List[int]
        :rtype: List[int]
        """
        res = []; dictionary = {}; addedNum = {}
        for num in nums1:
            dictionary[num] = True;
        for num in nums2:
            if dictionary.has_key(num) and not addedNum.has_key(num):
                res.append(num);
                addedNum[num] = True;
        return res;