using System;

using System.Collections.Generic;

using System.Security.Cryptography;

public class Program

{

    private const int ITERATIONS = 100000;

​

    HashSet<long> _ids = new HashSet<long>();

    public void Main()

    {

        int collisions = 0;

        long min = long.MaxValue;

        long max = long.MinValue;

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

        {

            long id = GenerateKey();

            if (!_ids.Add(id))

            {

                collisions++;

            }

            if (id < min)

            {

                min = id;

            }

            if (id > max)

            {

                max = id;

            }

        }

​

        Console.WriteLine($"Min: {min}");

        Console.WriteLine($"Max: {max}");

        Console.WriteLine($"Unique IDS: {_ids.Count}/{ITERATIONS}");

        Console.WriteLine($"Collisions: {collisions}");

    }

    private static long GenerateKey()

    {            

        byte[] bytes = new byte[2];

        RNGCryptoServiceProvider.Create().GetBytes(bytes);

        uint counter = BitConverter.ToUInt16(bytes, 0);

        long now = DateTime.Now.Ticks;

        long id = (now << 16) | counter;

        return id;

    }

​

}