using System;

using System.Linq;

using System.Collections.Generic;

​

namespace Split_a_number

{

    public class Program

    {

        // http://stackoverflow.com/q/25380719/69809

        public static void Main(string[] args)

        {

            foreach (var r in Split("59145"))

                Console.WriteLine(string.Join(",", r));

        }

​

        static IEnumerable<List<string>> Split(string input)

        {

            return Split(input, new List<string>());

        }

​

        static IEnumerable<List<string>> Split(string input, List<string> current)

        {

            if (input.Length == 0)

            {

                yield return current;

            }

​

            if (input.Length >= 1)

            {

                var copy = current.ToList();

                copy.Add(input.Substring(0, 1));

                foreach (var r in Split(input.Substring(1), copy))

                    yield return r;

            }

​

            if (input.Length >= 2)

            {

                var copy = current.ToList();

                copy.Add(input.Substring(0, 2));

                foreach (var r in Split(input.Substring(2), copy))

                    yield return r;

            }

        }

    }

}

​