for (int i = 0; i < array.Length; i++)
            {
                array[i] = rand.Next(0, 20);
                Console.Write(array[i] + " ");
            }
            System.Collections.ArrayList unique = new System.Collections.ArrayList();

            for (int i = 0; i < array.Length; i++)
                if (unique.IndexOf(array[i]) == -1)
                    unique.Add(array[i]);

            Console.WriteLine();
            for (int i = 0; i < unique.Count; i++)
                Console.Write(unique[i] + " ");