intersection.swift

//Given two arrays, write a function to compute their intersection.
//Example 1:
//
//Input: nums1 = [1,2,2,1], nums2 = [2,2]
//Output: [2]
//Example 2:
//
//Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
//Output: [9,4]
//Note:
//
//Each element in the result must be unique.
//The result can be in any order.

func intersection(_ nums1: [Int], _ nums2: [Int]) -> [Int] {
    let numSet = Set(nums1)
    return Array(numSet.intersection(nums2))
}

intersection([1,2,2,1], [2,2])
intersection([4,9,5], [9,4,9,8,4])