using System;

​

using KGySoft.CoreLibraries;

using KGySoft.Diagnostics;

public class Program

{

    public static void Main()

    {

        new PerformanceTest<int> { TestName = "long.MaxValue", Iterations = 1_000_000, Repeat = 3, CpuAffinity = null }

            .AddCase(() => GetStringLengthLog10(long.MaxValue), "Log10")

            .AddCase(() => GetStringLengthBruteForce(long.MaxValue), "Brute force")

            .DoTest()

            .DumpResults(Console.Out);

        new RandomizedPerformanceTest<int> { TestName = "Random values", Iterations = 1_000_000, Repeat = 3, CpuAffinity = null }

            .AddCase(rnd => GetStringLengthLog10(rnd.NextInt64()), "Log10")

            .AddCase(rnd => GetStringLengthBruteForce(rnd.NextInt64()), "Brute force")

            .DoTest()

            .DumpResults(Console.Out);

    }

    private static int GetStringLengthLog10(long value)

    {

        int sign;

        if (value < 0)

        {

            value = -value;

            sign = 1;

        }

        else

            sign = 0;

​

        return (int)Math.Log10(value) + 1 + sign;

    }

    private static int GetStringLengthBruteForce(long value)

    {

        int sign;

        if (value < 0)

        {

            value = -value;

            sign = 1;

        }

        else

            sign = 0;

        if (value < 10) return 1 + sign;

        if (value < 100) return 2 + sign;

        if (value < 1000) return 3 + sign;

        if (value < 10000) return 4 + sign;

        if (value < 100000) return 5 + sign;

        if (value < 1000000) return 6 + sign;

        if (value < 10000000) return 7 + sign;

        if (value < 100000000) return 8 + sign;

        if (value < 1000000000) return 9 + sign;

        if (value < 10000000000) return 10 + sign;

        if (value < 100000000000) return 11 + sign;

        if (value < 1000000000000) return 12 + sign;

        if (value < 10000000000000) return 13 + sign;

        if (value < 100000000000000) return 14 + sign;

        if (value < 1000000000000000) return 15 + sign;

        if (value < 10000000000000000) return 16 + sign;

        if (value < 100000000000000000) return 17 + sign;

        if (value < 1000000000000000000) return 18 + sign;

        return 19 + sign;

    }

}

​

public class RandomizedPerformanceTest<T> :  PerformanceTestBase<Func<Random, T>, T>

{

    private Random random;

    protected override void OnBeforeCase() => random = new Random(0);

    protected override T Invoke(Func<Random, T> del) => del.Invoke(random);

}