public static void Main()
        {
            Permutation p = new Permutation();
            List<int[]> result = p.permutationUnique(new int[] { 1,1,1 });
            foreach (int[] a in result) {
                foreach (int i in a) {
                    Console.Write(i + " ");
                }
                Console.WriteLine();
            }

            Console.ReadLine();
        }