Leetcode 2215

Three easy question in a row, next might be hard. there is not much to talk about for this question.

class Solution {
    public List<List<Integer>> findDifference(int[] nums1, int[] nums2) {
        Set<Integer> seen1 = new HashSet<>();
        Set<Integer> seen2 = new HashSet<>();
        for(int num : nums1){
            seen1.add(num);
        }
        Set<Integer> distinct2 = new HashSet<>();
        for(int num : nums2){
            seen2.add(num);
            if(!seen1.contains(num)){
                distinct2.add(num);
            }
        }
        Set<Integer> distinct1 = new HashSet<>();
        for(int num : nums1){
            if(!seen2.contains(num)){
                distinct1.add(num);
            }
        }
        return List.of(new ArrayList<>(distinct1),new ArrayList<>(distinct2));
    }
}