II_2 2. magasprog gyak házi

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

namespace ConsoleApplication1
{
    class cd
    {
        protected int year;
        protected int cost;
        protected int tracks;

        public void set_year(int x)
        {

            if (1970 <= x && x <= 2013)
            {
                year = x;
            }

            else
            {
                throw new Exception("Rossz évszám!");
            }
        }

        public void set_const(int x)
        {

            if (200 <= x && x <= 10000)
            {
                cost = x;
            }

            else
            {
                throw new Exception("nem jó árat adtál meg");
            }
        }

        public void set_tracks(int a)
        {

            if (1 <= a && a <= 20)
            {
                tracks = a;
            }

            else
            {
                throw new Exception("Nem megfelelő a trackek száma!");
            }
        }


        public int get_year()
        {
            return year;
        }

        public int get_cost()
        {
            return cost;
        }

        public int get_tracks()
        {
            return tracks;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            List<cd> L = new List<cd>();
            Random rand = new Random();
            for (int i = 0; i < 100; i++)
            {
                cd c = new cd();
                c.set_const(rand.Next(200, 10001));
                c.set_tracks(rand.Next(1, 21));
                c.set_year(rand.Next(1970, 2014));
                L.Add(c);
            }

            double summa = 0;
            for (int i = 0; i < L.Count; i++)
            {
                summa += L[i].get_cost();
            }

            double atlag = summa / L.Count;
            Console.WriteLine("Átlagosan egy CD ára: {0}", atlag);

            Console.ReadLine();
        }
    }
}