using System;

using System.Collections.Concurrent;

using System.Collections.Generic;

using System.Linq;

using System.Threading;

​

public class Program

{

    static ConcurrentDictionary<string, int> _concurrent = new ConcurrentDictionary<string, int>();

    //static Dictionary<string, int> _dictionary = new Dictionary<string, int>();

​

    public static void Main()

    {

        Thread thread1 = new Thread(new ThreadStart(AddToDict));

        Thread thread2 = new Thread(new ThreadStart(AddToDict));

        thread1.Start();

        thread2.Start();

        thread1.Join();

        thread2.Join();

        Console.WriteLine("Average: {0}", _concurrent.Values.Average());

        //Console.WriteLine("Average: {0}", _dictionary.Values.Average());

    }

​

    static void AddToDict()

    {

        for (int i = 0; i < 6000; i++)

        {

            _concurrent.TryAdd(i.ToString(), i);

            //_dictionary.Add(i.ToString(), i);

        }

    }

}