RolliTheCoder

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

namespace _3.RoliTheCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var dict = new Dictionary<int, Dictionary<string, List<string>>>();
            while (true)
            {
                string command = Console.ReadLine();
                if (command == "Time for Code")
                {
                    break;
                }
                if (IsValid(command) == false)
                {
                    continue;
                }
                string[] tokens = command.Split().ToArray();
                int id = int.Parse(tokens[0]);
                string eventName = tokens[1].TrimStart('#');
                if (tokens.Length <= 2)
                {
                    if (!dict.ContainsKey(id))
                    {
                        List<string> insideList = new List<string>();
                        var insideDict = new Dictionary<string, List<string>>();
                        insideDict.Add(eventName, insideList);
                        dict.Add(id, insideDict);
                        continue;
                    }

                }
                List<string> inner = new List<string>();
                for (int i = 2; i < tokens.Length; i++)
                {
                    inner.Add(tokens[i]);
                }
                var innerList = inner.Distinct().ToList();
                if (!dict.ContainsKey(id))
                {
                    var insideDict = new Dictionary<string, List<string>>();
                    insideDict.Add(eventName, innerList);
                    dict.Add(id, insideDict);
                }
                else
                {
                    if (dict[id].ContainsKey(eventName))
                    {
                        for (int i = 0; i < innerList.Count; i++)
                        {
                            if (!dict[id][eventName].Contains(innerList[i]))
                            {
                                dict[id][eventName].Add(innerList[i]);
                            }
                        }
                    }
                }
            }
            foreach (var item in dict.OrderByDescending(x => dict[x.Key].Values.First().Count).ThenBy(y => dict[y.Key].Values.First()))
            {
                foreach (var party in item.Value.OrderBy(x => x))
                {
                    Console.WriteLine($"{party.Key} - {party.Value.Count}");
                    foreach (var person in party.Value.OrderBy(x => x))
                    {
                        Console.WriteLine($"{person}");
                    }
                }
            }
        }

        static bool IsValid(string command)
        {
            string pattern = @"([0-9]+) (#[A-Za-z0-9]+)( (@[A-Za-z]+))*";
            var match = Regex.Match(command, pattern);
            if (match.Success)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
    }
}