Dragon Army

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

class Program
{
    public static void Main()
    {
#if DEBUG
        Console.SetIn(new StreamReader("../../input.txt"));
#endif
        var dragonDictionary = new Dictionary<string, SortedSet<Dragon>>();

        int dragonCount = int.Parse(Console.ReadLine());
        for (int counter = 0; counter < dragonCount; counter++)
        {
            Dragon dragon = ReadDragon();
            UpdateDragonDictionary(dragonDictionary, dragon);
        }

        foreach (var pair in dragonDictionary)
        {
            Console.WriteLine("{0}::({1:F2}/{2:F2}/{3:F2})",
                pair.Key,
                pair.Value
                    .Select(dragon => dragon.Damage)
                    .Average(),
                pair.Value
                    .Select(dragon => dragon.Health)
                    .Average(),
                pair.Value
                    .Select(dragon => dragon.Armor)
                    .Average());

            Console.WriteLine(string.Join("\n", pair.Value));
        }
    }

    private static void UpdateDragonDictionary(Dictionary<string, SortedSet<Dragon>> dragonDictionary, Dragon dragon)
    {
        if (!dragonDictionary.ContainsKey(dragon.Type))
        {
            dragonDictionary[dragon.Type] =
                new SortedSet<Dragon>(DragonComparer.GetComparer());
        }

        if (dragonDictionary[dragon.Type].Contains(dragon))
            dragonDictionary[dragon.Type].Remove(dragon);

        dragonDictionary[dragon.Type].Add(dragon);
    }

    private static Dragon ReadDragon()
    {
        string[] dragonArgs = Console.ReadLine().Split();

        string type = dragonArgs[0];
        string name = dragonArgs[1];
        int? damage = (dragonArgs[2] != "null")
            ? (int?)int.Parse(dragonArgs[2])
            : null;
        int? health = (dragonArgs[3] != "null")
            ? (int?)int.Parse(dragonArgs[3])
            : null;
        int? armor = (dragonArgs[4] != "null")
            ? (int?)int.Parse(dragonArgs[4])
            : null;

        return new Dragon(type, name, damage, health, armor);
    }
}

class Dragon
{
    private const int DefaultDamage = 45;
    private const int DefaultHealth = 250;
    private const int DefaultArmor = 10;

    public string Name { get; private set; }
    public string Type { get; private set; }
    public int Damage { get; private set; }
    public int Health { get; private set; }
    public int Armor { get; private set; }

    public Dragon(string type, string name, int? damage, int? health, int? armor)
    {
        Name = name;
        Type = type;
        Damage = damage ?? DefaultDamage;
        Health = health ?? DefaultHealth;
        Armor = armor ?? DefaultArmor;
    }

    // override object.Equals
    public override bool Equals(object obj)
    {
        if (obj is Dragon && obj != null)
        {
            Dragon dragon = (Dragon)obj;
            return (dragon.Name == this.Name && dragon.Type == this.Type);
        }

        return false;
    }

    // override object.GetHashCode
    public override int GetHashCode()
    {
        return (Name + Type).GetHashCode();
    }

    // override object.ToString
    public override string ToString()
    {
        return string.Format("-{0} -> damage: {1}, health: {2}, armor: {3}",
            Name,
            Damage,
            Health,
            Armor);
    }
}

class DragonComparer : IComparer<Dragon>
{
    public int Compare(Dragon x, Dragon y)
    {
        return string.Compare(x.Name, y.Name);
    }

    public static IComparer<Dragon> GetComparer()
    {
        return new DragonComparer();
    }
}