gistfile1.txt

using System.Diagnostics;

const int CountPerInnerLoop = 10_000_000;
const int Iterations = 5;

for (int iteration = 1; iteration <= Iterations; iteration++)
{
    Console.WriteLine($"Iteration {iteration}");

    var list = new List<int>();
    for (int i = 0; i <= 10000; i++)
    {
        list.Add(3);
    }

    var list2 = new List<int>();
    for (int i = 0; i <= 10000; i++)
    {
        list2.Add(i);
    }

    var watch = new Stopwatch();
    watch.Start();
    for (int i = 0; i < CountPerInnerLoop; i++)
    {
        list.Contains(10000);
    }
    watch.Stop();
    Console.WriteLine(watch.Elapsed.Ticks);

    var hash = list.ToHashSet();
    watch = new Stopwatch();
    watch.Start();
    for (int i = 0; i < CountPerInnerLoop; i++)
    {
        hash.Contains(10000);
    }
    watch.Stop();
    Console.WriteLine(watch.Elapsed.Ticks);

    watch = new Stopwatch();
    watch.Start();
    for (int i = 0; i < CountPerInnerLoop; i++)
    {
        list2.Contains(10000);
    }
    Console.WriteLine(watch.Elapsed.Ticks);
}