Моля, ако някой има време, да ми прегледа решението и да ми каже къде бъркам, защото не зацепвам. Мерси!

5. Teamwork Projects

It's time for the teamwork projects and you are responsible for gathering the teams. First you will receive an integer - the count of the teams you will have to register. You will be given a user and a team, separated with “-”.  The user is the creator of the team. For every newly created team you should print a message:

"Team {teamName} has been created by {user}!".

Next, you will receive an user with a team, separated with "->", which means that the user wants to join that team. Upon receiving the command: “end of assignment”, you should print every team, ordered by the count of its members (descending) and then by name (ascending). For each team, you have to print its members sorted by name (ascending). However, there are several rules:

• If an user tries to create a team more than once, a message should be displayed:
  •  
• A creator of a team cannot create another team – the following message should be thrown:
  • {user} cannot create another team!"
• If an user tries to join a non-existent team, a message should be displayed:
  •  
• A member of a team cannot join another team – the following message should be thrown:
  •  
• In the end, teams with zero members (with only a creator) should disband and you have to print them ordered by name in ascending order.
• Every valid team should be printed ordered by name (ascending) in the following format:

Examples

Решението: 

using System;
using System.Collections.Generic;
using System.Linq;

namespace ObjectsAndClassesExercise
{
    class Program

    {
        static void Main(string[] args)
        {
            int count = int.Parse(Console.ReadLine());
            List<Team> allTeams = new List<Team>();

            for (int i = 0; i < count; i++)
            {
                string[] teamTokens = Console.ReadLine().Split("-");
                string creator = teamTokens[0];
                string name = teamTokens[1];

                Team existingTeam = allTeams.Find(t => t.TeamName == name);
                Team existingTeamCreator = allTeams.Find(t => t.Creator == creator);

                if (existingTeam != null)
                {
                    Console.WriteLine($"Team {name} was already created!");
                    continue;
                }

                if (existingTeamCreator != null)
                {
                    Console.WriteLine($"{creator} cannot create another team!");
                    continue;
                }

                Team myTeam = new Team(teamTokens[0], teamTokens[1]);
                allTeams.Add(myTeam);
                Console.WriteLine($"Team {myTeam.TeamName} has been created by {myTeam.Creator}!");
            }

            string line = Console.ReadLine();

            while (line != "end of assignment")
            {
                string[] tokens = line.Split("->");
                string member = tokens[0];
                string name = tokens[1];

                Team existingTeam = allTeams.Find(t => t.TeamName == name);
                Team existingTeamMember = allTeams.Find(t => t.Members.Contains(member) || t.Creator == member);

                if (existingTeam == null)
                {
                    Console.WriteLine($"Team {name} does not exist!");
                    line = Console.ReadLine();
                    continue;
                }

                if (existingTeamMember != null)
                {
                    Console.WriteLine($"Member {member} cannot join team {name}!");
                    line = Console.ReadLine();
                    continue;
                }

                existingTeam.Members.Add(member);
                line = Console.ReadLine();
            }

            List<string> allDisbandedTeams = allTeams
                .Where(a => a.Members.Count == 0).
                OrderBy(a => a.TeamName).
                Select(a => a.TeamName). // Защото не искаме списък от Team, а списък от стрингове
                ToList();
            allTeams.RemoveAll(t => t.Members.Count == 0);
            List<Team> sortedTeams = allTeams
                .OrderByDescending(t => t.Members.Count)
                .ThenBy(t => t.TeamName)
                .ToList();
            //.Foreach(t => Console.WriteLine(t)); ;

            foreach (Team team in sortedTeams)
            {
                Console.WriteLine(team.ToString());
            }
            Console.WriteLine("Teams to disband:");
            foreach (string team in allDisbandedTeams)
            {
                Console.WriteLine(team);
            }
        }
    }
}

class Team
{
    public Team(string creator, string team)
    {
        this.Creator = creator;
        this.TeamName = team;

        this.Members = new List<string>();
    }

    public string Creator { get; set; }
    public string TeamName { get; set; }
    public List<string> Members { get; set; }   

    public override string ToString()
    {
        List<string> sortedMembers = this.Members.OrderBy(t => t).ToList();
        string output = $"{this.TeamName}\n";
        output += $"- {this.Creator}\n";

        for (int i = 0; i < sortedMembers.Count; i++)
        {
            output += $"-- {this.Members[i]}\n";
        }

        return output.Trim();
    }
}