04. Roli The Coder

gistfile1.txt

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
class Program
{
    static void Main()
    {
        Dictionary<int, List<string>> eventNamesParticipants = new Dictionary<int, List<string>>();
        while (true)
        {
            List<string> input = Console.ReadLine().Split(' ').Select(data => data.Trim()).ToList();
            if (input[0] == "Time")
            {
                break;
            }
            if (!CheckValidity(input))
            {
                int id = int.Parse(input[0]);
                string eventName = input[1].Substring(1);

                if (!eventNamesParticipants.ContainsKey(id))
                {
                    eventNamesParticipants.Add(id, new List<string>());
                    eventNamesParticipants[id].Add(eventName);

                    for (int i = 2; i < input.Count; i++)
                    {
                        eventNamesParticipants[id].Add(input[i]);
                    }
                }
                if (eventNamesParticipants[id][0] == eventName)
                {
                    for (int i = 2; i < input.Count; i++)
                    {
                        eventNamesParticipants[id].Add(input[i]);
                    }
                }
                eventNamesParticipants[id] = eventNamesParticipants[id].Distinct().ToList();
            }
        }
        foreach (var events in eventNamesParticipants.OrderByDescending(participants => participants.Value.Count).ThenBy(events => events.Value[0]))
        {
            Console.WriteLine($"{events.Value[0]} - {events.Value.Count - 1}");
            foreach (var participant in events.Value.OrderBy(name => name))
            {
                if (participant.StartsWith("@"))
                {
                    Console.WriteLine(participant);
                }
            }
        }
    }
    static bool CheckValidity(List<string> input)
    {
        if (!input[1].StartsWith("#"))
        {
            return true;
        }
        for (int i = 2; i < input.Count; i++)
        {
            Match match = Regex.Match(input[i], @"^@[a-zA-Z-'0-9]+$");

            if (!match.Success)
            {
                return true;
            }
            
        }
        return false;
    }
}