04. Roli The Coder

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace _04.Roli__The_Coder
{

    public class Event
    {
        public string Name {get; set;}
        public List<string> Participants {get; set;}

        public Event(string name,List<string> participants)
        {
            Name = name;
            Participants = participants;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Regex regex = new Regex(@"^(?<id>\d+)\s*#(?<eventName>\w+)\s*(?<participants>(?:@[a-zA-Z\d'-]+\s*)*)$");
            Dictionary<int, Event> dictEvents = new Dictionary<int, Event>();

            while (true)
            {
                string line = Console.ReadLine();

                if (line == "Time for Code")
                {
                    break;
                }

                Match eventMatch = regex.Match(line);
                if (eventMatch.Success == false)
                {
                    continue;
                }

                int id = int.Parse(eventMatch.Groups["id"].Value);
                string eventName = eventMatch.Groups["eventName"].Value;
                List<string> participants = eventMatch.Groups["participants"].Value.Split(new[] { ' ' },
                    StringSplitOptions.RemoveEmptyEntries).ToList();

                if (dictEvents.ContainsKey(id) == false)
                {
                    dictEvents.Add(id, new Event(eventName, participants));
                }
                else if (dictEvents[id].Name == eventName)
                {
                    dictEvents[id].Participants.AddRange(participants);
                    dictEvents[id].Participants = dictEvents[id].Participants.Distinct().ToList();
                }
            }
            foreach (var e in dictEvents)
            {
                e.Value.Participants = e.Value.Participants.Distinct().ToList();
            }

            var ordered = dictEvents.Select(a => a.Value).OrderByDescending(e => e.Participants.Count).ThenBy(e => e.Name);

            foreach (var e in ordered)
            {
                Console.WriteLine("{0} - {1}",e.Name,e.Participants.Count);
                foreach (var p in e.Participants.OrderBy(p => p))
                {
                    Console.WriteLine(p);
                }
            }
        }
    }
}