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.
思路：利用 C++ 中的set 容器。
转载于:https://www.cnblogs.com/vincent93/p/6686529.html
