using System;

​

public delegate void ItemFoundCallback(int index);

public static class ItemFinder

{

    public static void FindItem(string[] list, string stringToFind, ItemFoundCallback callback)

    {

    // TODO: implement this

        for(int i =0; i<list.Length -1; i++)

        {

            if(list[i].Contains(stringToFind))

            {

                callback(i);

            }

        }

    }

}

​

public class Program

{

    public static void Announce(int i)

    {

        Console.WriteLine("String found at index {0}!", i);

    }

​

    public static void Main()

    {

        string[] s =

        {

        "Pikachu", "Squirtle", "Ditto", "Pikachu", "Ditto", "Dragonite"

        }

​

        ;

        Console.WriteLine("Finding Pikachu...");

        ItemFinder.FindItem(s, "Pikachu", Announce);

        Console.WriteLine("Finding Ditto...");

        ItemFinder.FindItem(s, "Ditto", Announce);

    }

}