using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public class MyComparer : IEqualityComparer<string>

    {

        public bool Equals(string one, string two)

        {

            Console.WriteLine("{0} v.s. {1} => {2}", one, two, one.Equals(two));

            return one == two;

        }

        public int GetHashCode(string value)

        {

            var hash = value.GetHashCode();

            Console.WriteLine("hash: {0} => {1}", value, hash);

            return hash;            

        }

    }

    public static void Main()

    {

        Console.WriteLine("Intersections demo\n");

        var listOne = new [] {"One","Two", "Three"};

        var listTwo = new [] {"One1","Two2", "Three"};

        var comparer = new MyComparer();

        var intersections = listOne.Intersect(listTwo, comparer).ToList();

        if (!intersections.Any())

        {

            Console.WriteLine("\nNo intersections.");

            return;

        }

        Console.WriteLine("\nPlease find intersections below:");

        foreach (var item in intersections)

        {

            Console.WriteLine(" - {0}", item);

        }

    }

}