using System;

using System.Diagnostics;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("array loop:");

        ArrayLoopSpeedTest();

        Console.WriteLine("custom array:");

        CustomArrayLoopTest();

    }

​

    public static void ArrayLoopSpeedTest()

    {

        Stopwatch sw = Stopwatch.StartNew();

        bool[] array = new bool[7000];

        array[10] = true;

        array[27] = true;

        array[326] = true;

        array[430] = true;

        array[500] = true;

        array[600] = true;

        array[80] = true;

        array[660] = true;

        array[350] = true;

        array[2520] = true;

        array[3130] = true;

        array[924] = true;

        var trueCount = 0;

        for (var i = 0; i < array.Length; i++)

        {

            if (array[i])

            {

                trueCount++;

            }

        }

​

        sw.Stop();

        Console.WriteLine(trueCount);

        Console.WriteLine(sw.Elapsed);

    }

​

    public static void CustomArrayLoopTest()

    {

        Stopwatch sw = Stopwatch.StartNew();

        CustomBoolArrayWrapper array = new CustomBoolArrayWrapper(7000);

        array[10] = true;

        array[27] = true;

        array[326] = true;

        array[430] = true;

        array[500] = true;

        array[600] = true;

        array[80] = true;

        array[660] = true;

        array[350] = true;

        array[2520] = true;

        array[3130] = true;

        array[924] = true;

        var trueCount = array.TrueCount;

        sw.Stop();

        Console.WriteLine(trueCount);

        Console.WriteLine(sw.Elapsed);

    }

​

    public class CustomBoolArrayWrapper

    {

        private readonly bool[] _internalArray;

        private int _trueCount = 0;

        public CustomBoolArrayWrapper(uint arraySize)

        {

            this._internalArray = new bool[arraySize];

        }

​

        public int TrueCount => this._trueCount;

        public bool this[int index]

        {

            get

            {

                return this._internalArray[index];

            }

​

            set

            {

                if (this._internalArray[index] == value)

                {

                    return;

                }

​

                this._internalArray[index] = value;

                if (value)

                {

                    this._trueCount++;

                }

                else

                {

                    this._trueCount--;

                }

            }

        }

    }

}