using System;

using System.Text.RegularExpressions;

public partial class Program

{

    private static readonly Regex HTMLNeedReplace = new Regex("<(\\S+) *[^>]*>", RegexOptions.Compiled);

    private static readonly Regex HTMLNeedReplaceNoBacktrack = new Regex("<(\\S+) *[^>]*>", RegexOptions.Compiled | RegexOptions.NonBacktracking);

    public static void Main()

    {

        string string1 = $$"""<a href="Home?DashboardID=100100&amp;TableName=Users&amp;Search=UserID~224" jslink="1"><div class="PicAndDescPill"><img src="https://images.encompass8.com/Support/S3UserAvatar/b46b61f88fdeefa44f52e7360a667011-THUMB.JPG" loading="lazy"><span class="PicPillName">Matt Loidolt</span> <span class="PicPillTitle">(Administration) </span></div></a>""";

        string stringTmp = string1;

        System.Diagnostics.Stopwatch sw = System.Diagnostics.Stopwatch.StartNew();

​

        for (int i = 0; i < 100000; i++)

        {

            MatchCollection matches = HTMLNeedReplace.Matches(stringTmp);

        }

        sw.Stop();

        Console.WriteLine("Execution time (interpolation): {0} ms", sw.ElapsedMilliseconds);

        stringTmp = string1;

        sw.Reset();

        sw.Start();

        // Call the function to be tested.

        for (int i = 0; i < 100000; i++)

        {

            MatchCollection matches = HTMLNeedReplaceNoBacktrack.Matches(stringTmp);

        }

        sw.Stop();

        Console.WriteLine("Execution time (StringBuilder): {0} ms", sw.ElapsedMilliseconds);

    }

}