public static int[] Sort(this int[] array)
        {
            var s = new SmoothSort();

            s.Sort(array);
            return(array);
        }
        static void Main(string[] args)
        {
            int[] array  = { 19, 21, 156, 120, 12, 7 };
            int   length = array.Length;

            SmoothSort smoothsort = new SmoothSort();

            smoothsort.sort(array);

            PrintSortedArray(array);
        }