using System;

using System.Collections.Generic;   

​

public class Program

{

    public abstract class Item {

        public abstract string GetName();

        public abstract int GetPrice();

    }

    public abstract class Weapon : Item {

        public abstract void Swing();

    }

    public abstract class Armor : Item {

        public abstract void Wear();

    }

    public class Inventory {

        private Dictionary<int, Item> items = new Dictionary<int, Item>();

        public void Put(int index, Item item) {

            items[index] = item;

        }

        public Item Get(int index) {

            return items[index];

        }

    }

    public class Sword : Weapon {

        override public void Swing() {

            Console.WriteLine("Sword swing");

        }

        override public int GetPrice() {

            return 100;

        }

        override public string GetName() {

            return "Sword";

        }

    }

    public class Breastplate : Armor {

        override public void Wear() {

            Console.WriteLine("Breastplate armor equipped.");

        }

        override public int GetPrice() {

            return 200;

        }

        override public string GetName() {

            return "Breastplate";

        }

    }

    public static void Main()

    {

        Inventory inventory = new Inventory();

        // Spawn items

        Weapon item1 = new Sword();

        Armor item2 = new Breastplate();

        // Put items into the inventory

        inventory.Put(0, item1);

        inventory.Put(1, item2);

        // Get item from the inventory and use it.

        // This is the issue, how to avoid these type casts?

        Item item = inventory.Get(0);

        Weapon itemAsWeapon = (Weapon)(item);

        Sword itemAsSword = (Sword)(itemAsWeapon);

        // Use the item

        itemAsSword.Swing();

    }

}