public static string Shuffle(string source, int klet)
        {
            UShuffle us = new UShuffle();

            char[] s = source.ToCharArray();
            char[] t = new char[s.Length];

            us.shuffle1(s, s.Length, klet);
            us.shuffle2(t);

            return(new string(t));
        }
        public static List <string> Shuffle(string source, int klet, int repeat)
        {
            UShuffle us = new UShuffle();

            char[] s = source.ToCharArray();
            char[] t = new char[s.Length];

            us.shuffle1(s, s.Length, klet);
            List <string> result = new List <string>();

            for (int i = 0; i < repeat; i++)
            {
                us.shuffle2(t);
                result.Add(new string(t));
            }
            return(result);
        }