PC Game Shop

using System;

namespace PCGameShop
{
    class Program
    {
        static void Main(string[] args)
        {
            int volume = int.Parse(Console.ReadLine());
            double hearthstones = 0,
                    fornites = 0,
                    overwatches = 0,
                    others = 0;

            for (int i = 0; i < volume; i++)
            {
                string game = Console.ReadLine();
                switch (game)
                {
                    case "Hearthstone":
                        hearthstones++;
                        break;
                    case "Fornite":
                        fornites++;
                        break;
                    case "Overwatch":
                        overwatches++;
                        break;
                    default:
                        others++;
                        break;
                }
            }

            Console.WriteLine($"Hearthstone - { hearthstones / volume * 100:F2}%");
            Console.WriteLine($"Fornite - { fornites / volume * 100:F2}%");
            Console.WriteLine($"Overwatch - { overwatches / volume * 100:F2}%");
            Console.WriteLine($"Others - { others / volume * 100:F2}%");
        }
    }
}

РЕШЕНИЕ С РЕЧНИК, ТЕРНАРЕН ОПЕРАТОР И FOREACH:

using System;
using System.Collections.Generic;

namespace PCGameShop
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<string, double> games = new Dictionary<string, double>() {
                { "Hearthstone", 0 }, { "Fornite", 0 }, { "Overwatch", 0 }, { "Others", 0 }
            };
            int volume = int.Parse(Console.ReadLine());

            for (int i = 0; i < volume; i++)
            {
                string game = Console.ReadLine();
                games[games.ContainsKey(game) ? game : "Others"]++;
            }

            foreach (var game in games)
            {
                Console.WriteLine($"{game.Key} - { game.Value / volume * 100:F2}%");
            }
        }
    }
}