ParallelSqrChain

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Threading.Tasks;

namespace sqr
{
    class result
    {
        public  int i { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Stopwatch sw = new Stopwatch();
           
            int res = 0;
            result r = new result();
            int x = 10000000;

            Console.WriteLine("result for parallel for with local thread sum and lock:");
            sw.Start();
            Parallel.For(1, x + 1, () => 0,
                (i, state, localsum) => { if (sqrchan89(i))localsum++; return localsum; },
                (localsum) => { lock (r) r.i += localsum; });
            sw.Stop();
            Console.WriteLine(r.i);
            Console.WriteLine(sw.Elapsed);
            Console.WriteLine("--------------------------");

            Console.WriteLine("result for parallel for with local thread sum and Interlocked.Add:");
            sw.Restart();
            Parallel.For(1, x + 1, () => 0,
               (i, state, localsum) => { if (sqrchan89(i))localsum++; return localsum; },
               (localsum) => { System.Threading.Interlocked.Add(ref res, localsum); });
            sw.Stop();
            Console.WriteLine(res);
            Console.WriteLine(sw.Elapsed);
            Console.WriteLine("--------------------------");

            res = 0;

            Console.WriteLine("result for parallel for with Interlocked.Add:");
            Parallel.For(1, x + 1, c => { if (sqrchan89(c))System.Threading.Interlocked.Add(ref res, 1); });
            sw.Stop();
            Console.WriteLine(res);
            Console.WriteLine(sw.Elapsed);
            Console.ReadLine();
        }
        public static int sqrSum(int number)
        {
            int res = 0;
            while (number > 0)
            {
                int x = number % 10;
                res += (int)Math.Pow(x, 2);
                number /= 10;
            }

            return res;
        }
        static bool sqrchan89(int number)
        {
            if (number == 89) return true;
            else if (number == 1) return false;
            else return sqrchan89(sqrSum(number));
        }
    }
}