infoRoadsRacers

Problem 2. Practice sessions
The racers must practice for the race. Your job is to keep the records of the roads and the time for each lap. The track with the best time will be the chosen one for the finals.

Write a program, that keeps information about roads and the racers who practice on them.  When the practice begins, you’re going to start receiving data until you get the "END" message. There are three possible commands:
• "Add->{road}->{racer}"
o   Add the road if it doesn't exist in your collection and add the racer to it.
• "Move->{currentRoad}->{racer}->{nextRoad}"
o   Find the racer on the current road and move him to the next one, only if he exists in the current road. Both roads will always be valid and will already exist.
• "Close->{road}"
o   Find the road and remove it from the sessions, along with the racers on it if it exists.
In the end, print all of the roads with the racers who have practiced and ordered by the count of the racers in descending order, then by the roads in ascending order. The output must be in the following format:
Practice sessions:
{road}
++{racer}
++{racer}
++{racer}
………………………..
Input / Constraints
• You will be receiving lines of information in the format described above, until you receive the "END" command.
• The input will always be in the right format.
• Both roads from the "Move" command will always be valid and you don't need to check them explicitly.
Output
• Print the roads with their racers in the format described above.
Examples
Input                                                        Output
Add->Glencrutchery Road->Giacomo Agostini                    Practice sessions:
Add->Braddan->Geoff Duke                                     Peel road
Add->Peel road->Mike Hailwood                                ++Mike Hailwood
Add->Glencrutchery Road->Guy Martin                          ++Giacomo Agostini
Move->Glencrutchery Road->Giacomo Agostini->Peel road        Glencrutchery Road
Close->Braddan                                               ++Guy Martin
END

Comments
We add racers to the roads they are racing on. When we receive the "Move" command, we check if Giacomo Agostini is on Glencrutchery Road and if he is, we remove him from it and add him to the next one - Peel road.
When we receive the "Close" command, we remove Brandon road and remove all its records. In the end we print the roads sorted by the count of racers on them and then by the names of the roads in ascending order.

Add->Glen Vine->Steve Hislop                                  Practice sessions:
Add->Ramsey road->John McGuinness                             Braddan
Add->Glen Vine->Ian Hutchinson                                ++Geoff Duke
Add->Ramsey road->Dave Molyneux                               ++Geoff Duke
Move->Ramsey road->Hugh Earnsson->Glen Vine                   ++Mike Hailwood
Add->A18 Snaefell mountain road->Mike Hailwood                Glen Vine
Add->Braddan->Geoff Duke                                      ++Steve Hislop
Move->A18 Snaefell mountain road->Mike Hailwood->Braddan      ++Ian Hutchinson
Move->Braddan->John McGuinness->Glen Vine                     Ramsey road
Close->A18 Snaefell mountain road                             ++John McGuinness
END                                                           ++Dave Molyneux


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

namespace FinalExam14042019
{
    class Program
    {
        static void Main(string[] args)
        {
            var infoRoadsRacers = new Dictionary<string, List<string>>();
            var inputData = "";
            while (!(inputData = Console.ReadLine()).Equals("END"))
            {
                var command = inputData.Split("->");
                switch (command[0])
                {
                    case "Add":
                        if (!infoRoadsRacers.ContainsKey(command[1]))
                        {
                            infoRoadsRacers.Add(command[1], new List<string>());
                        }
                        infoRoadsRacers[command[1]].Add(command[2]);
                        break;
                    case "Move":
                        if (infoRoadsRacers[command[1]].Contains(command[2]))
                        {
                            infoRoadsRacers[command[3]].Add(command[2]);
                            infoRoadsRacers[command[1]].Remove(command[2]);
                        }
                        break;
                    case "Close":
                        if (infoRoadsRacers.ContainsKey(command[1]))
                        {
                            infoRoadsRacers.Remove(command[1]);
                        }
                        break;
                }
            }
            Console.WriteLine("Practice sessions:");
            foreach (var road in infoRoadsRacers.OrderByDescending(x => x.Value.Count).ThenBy(x => x.Key))
            {
                Console.WriteLine(road.Key);
                foreach (var racer in road.Value)
                {
                    Console.WriteLine($"++{racer}");
                }
            }
        }
    }
}