01. Match Tickets

using System;

namespace MatchTicket
{
    class Program
    {
        static void Main(string[] args)
        {
            double budget = double.Parse(Console.ReadLine());
            string category = Console.ReadLine();
            int people = int.Parse(Console.ReadLine());

            if (people <= 4)
            {
                budget *= 0.25;
            }
            else if (people <= 9)
            {
                budget *= 0.4;
            }
            else if (people <= 24)
            {
                budget *= 0.5;
            }
            else if (people < 50)
            {
                budget *= 0.6;
            }
            else
            {
                budget *= 0.75;
            }

            if (category == "VIP")
            {
                budget -= 499.99 * people;
            }
            else
            {
                budget -= 249.99 * people;
            }

            if (budget >= 0)
            {
                Console.WriteLine($"Yes! You have {budget:F2} leva left.");
            }
            else
            {
                Console.WriteLine($"Not enough money! You need {Math.Abs(budget):F2} leva.");
            }
        }
    }
}

Решение с тернарен оператор:

using System;

namespace MatchTicket
{
    class Program
    {
        static void Main(string[] args)
        {
            double budget = double.Parse(Console.ReadLine());
            string category = Console.ReadLine();
            int people = int.Parse(Console.ReadLine());

            budget *=
                people <= 4 ? 0.25 :
                people <= 9 ? 0.4 :
                people <= 24 ? 0.5 :
                people < 50 ? 0.6 : 0.75;

            budget -= (category == "VIP" ? 499.99 : 249.99) * people;

            Console.WriteLine(budget >= 0 ? $"Yes! You have {budget:F2} leva left."
                : $"Not enough money! You need {Math.Abs(budget):F2} leva.");
        }
    }
}