Adv2015/D10.1/Program.cs

using System;
using System.Text;

namespace D10._1
{
    public class Program
    {
        static void Main(string[] args)
        {
            if (args.Length < 1) throw new ArgumentException();
            string input = args[0];

            int tries = 40;
            Apply(ref input, ref tries);

            Console.WriteLine($"The answer is : {input.Length}");
        }

        public static void Apply(ref string input, ref int tries)
        {
            while (tries > 0)
            {
                var ninput = new StringBuilder("");

                int i = 0;
                while (i < input.Length)
                {
                    char current = input[i];
                    int count = 0;
                    while (i < input.Length && input[i] == current)
                    {
                        count++;
                        i++;
                    }

                    ninput.Append(count);
                    ninput.Append(current);
                }

                input = ninput.ToString();
                tries--;
            }
        }
    }
}