using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp
{
    class Program
    {
        const int LOOP_COUNT = 900000;
        static long Calcute()
        {
            int Total = 0;
            for (int i = 0; i < 10000; i++) // add more iteration to make parallel faster than sequential
            {
                Total += 20 * i;
            }
            return Total;
        }

        static void SequentialCalcute()
        {
            var Counter = 0;
            long Total = 0;
            Stopwatch SW = new Stopwatch();
            SW.Start();
            for (int i = 0; i < LOOP_COUNT; i++)
            {
                Total = Calcute();
                ++Counter;
            }
            SW.Stop();
            Console.WriteLine("Sequential total seconds: " + SW.Elapsed.TotalSeconds + ", Counter: " + Counter + ", Total: " + Total);
        }

        static void ParallelCalcute()
        {
            var Counter = 0;
            long Total = 0;
            Stopwatch SW = new Stopwatch();
            SW.Start();
            Parallel.For(0, LOOP_COUNT, i =>
            {
                Total = Calcute();
                Interlocked.Add(ref Counter, 1);
            });
            SW.Stop();
            Console.WriteLine("Parallel total seconds: " + SW.Elapsed.TotalSeconds + ", Counter: " + Counter + ", Total: " + Total);
        }

        static void Main(string[] args)
        {
            Console.ReadKey();
            SequentialCalcute();
            ParallelCalcute();
            Console.ReadKey();
        }
    }
}