using System.Text.RegularExpressions;

using System;

public class Program

{

    public static void Main()

    {

        /*

         * We use capturing groups in the regex which has overhead for look ahead|behind

         * I don't think we acutallu use the capturing groups and could remove them to improve performance

         * It would only minimally improve performance since these are such simple regex.

         */

        //-- This allows any postitive integer values (no decimal, no seperator)

        Regex positiveNumbersRegex = new Regex("^\\d+$");

        Console.WriteLine("positiveNumbersRegex: " + positiveNumbersRegex.IsMatch("0"));

        //-- This allows a semi semver in that it only allows MAJOR[.MINOR[.PATCH]] with no support for identifiers (pre-release, build, ...)

        Regex buildVersionRegex = new Regex("^(\\d*)(\\.\\d+){0,2}$");

        Console.WriteLine("buildVersionRegex: " + buildVersionRegex.IsMatch("01.1.1"));

        //-- I think this should be case-insensitive

        Regex operationSystemRegex = new Regex("^(IOS|Android-Google|Android-Huawei|Unknown)$");

        Console.WriteLine("operationSystemRegex: " + operationSystemRegex.IsMatch("ios"));

        //This allows a semi semver in that it only allows MAJOR[.MINOR[.PATCH]] with no support for identifiers (pre-release, build, ...)

        Regex deviceOSVersionRegex = new Regex("^(\\d*)(\\.\\d+){0,2}$");

        Console.WriteLine("deviceOSVersionRegex: " + deviceOSVersionRegex.IsMatch("09.1"));

    }

}