import gnu.trove.set.TIntSet; import gnu.trove.set.hash.TIntHashSet; public class Example { public static void main(String[] args) { TIntSet intSet = new TIntHashSet(); intSet.add(1); intSet.add(2); intSet.add(3); boolean contains = intSet.contains(2); System.out.println("Contains 2: " + contains); int[] elements = intSet.toArray(); for (int element : elements) { System.out.println("Element: " + element); } } }