Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the result in any order.
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]
Use two hash sets: one for nums1, check nums2 against it, collect results in another set.
1class Solution {
2 public int[] intersection(int[] nums1, int[] nums2) {
3 Set<Integer> set1 = new HashSet<>();
4 Set<Integer> result = new HashSet<>();
5
6 for (int num : nums1) set1.add(num);
7 for (int num : nums2) {
8 if (set1.contains(num)) result.add(num);
9 }
10
11 return result.stream().mapToInt(Integer::intValue).toArray();
12 }
13}