If you have any suggestion about the solution, please let me know.

```
public int[] intersection(int[] nums1, int[] nums2) {
HashSet<Integer> set = new HashSet<>();
HashSet<Integer> set2 = new HashSet<>();
for(int i =0;i<nums1.length;i++){
set.add(nums1[i]);
}
for(int j =0;j<nums2.length;j++){
if(set.contains(nums2[j]))
set2.add(nums2[j]);
}
int a [] = new int[set2.size()];
Iterator<Integer> it = set2.iterator();
for(int i =0;i<a.length;i++){
a[i] = it.next();
}
return a;
}
```