using System;

using System.Collections.Generic;

​

namespace HashSetExample

{

    public class ItemDTO

    {

        public int Id { get; set; }

        public string Name { get; set; }

​

        // Override Equals method

        public override bool Equals(object obj)

        {

            if (obj == null || GetType() != obj.GetType())

            {

                return false;

            }

​

            ItemDTO other = (ItemDTO)obj;

            return Id == other.Id && Name == other.Name;

        }

​

        // Override GetHashCode method

        public override int GetHashCode()

        {

            return Id.GetHashCode() ^ Name.GetHashCode();

        }

    }

​

    class Program

    {

        static void Main(string[] args)

        {

            // Create a HashSet of ItemDTO

            HashSet<ItemDTO> items = new HashSet<ItemDTO>();

​

            // Insert elements into the HashSet

            items.Add(new ItemDTO { Id = 1, Name = "Item1" });

            items.Add(new ItemDTO { Id = 2, Name = "Item2" });

            items.Add(new ItemDTO { Id = 3, Name = "Item3" });

            items.Add(new ItemDTO { Id = 4, Name = "Item4" });

            items.Add(new ItemDTO { Id = 5, Name = "Item5" });

            items.Add(new ItemDTO { Id = 1, Name = "Item1" });

​

            // Access and display elements in the HashSet

            Console.WriteLine();

            Console.WriteLine("Elements in the HashSet:");

            foreach (var item in items)

            {

                Console.WriteLine($"Id: {item.Id}, Name: {item.Name}");

            }

​

            // Search for an element in the HashSet

            Console.WriteLine();

            var searchItem = new ItemDTO { Id = 3, Name = "Item3" };

            if (items.Contains(searchItem))

            {

                Console.WriteLine($"HashSet contains the item with Id {searchItem.Id} and Name {searchItem.Name}");

            }

            else

            {

                Console.WriteLine($"HashSet does not contain the item with Id {searchItem.Id} and Name {searchItem.Name}");

            }

​

            // Delete an element from the HashSet

            Console.WriteLine();

            var deleteItem = new ItemDTO { Id = 4, Name = "Item4" };

            if (items.Remove(deleteItem))

            {

                Console.WriteLine($"Item with Id {deleteItem.Id} and Name {deleteItem.Name} was removed from the HashSet");

            }

            else

            {

                Console.WriteLine($"Item with Id {deleteItem.Id} and Name {deleteItem.Name} was not found in the HashSet");

            }

​

            // Display elements after deletion

            Console.WriteLine();

            Console.WriteLine("Elements in the HashSet after deletion:");

            foreach (var item in items)

            {

                Console.WriteLine($"Id: {item.Id}, Name: {item.Name}");

            }

        }

    }

}