using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var list = new List<string>();

        list.Add("one");

        list.Add("two");

        list.Add("three");

        list.Add("four");

        list.Add("five");

        list.Add("six");

        list.Add("seven");

        list.Add("eight");

        list.Add("nine");

        var sw = new Stopwatch();

        sw.Start();

        var rows = Math.Floor((double) list.Count/3);

        for (int i = 0; i < 3; i++) {

            for (int j = 0; j < rows; j++) {

                var test = list[i+j*3];

            }

        }

        sw.Stop();

        Console.WriteLine(sw.Elapsed);

        sw.Reset();

        sw.Start();

        var rows2 = Math.Floor((double) list.Count/3);

        for (int i = 0; i < list.Count; i += 3) {

            var nodes = list.Skip(i).Take((int) rows);

            foreach (var node in nodes) {

                var test = node;

            }

        }

        sw.Stop();

        Console.WriteLine(sw.Elapsed);

        sw.Reset();

        sw.Start();

        var nodeList = new List<string>[3];

        for (var i = 0; i < list.Count; i++)

        {

            if (nodeList[i%3] == null)

            {

                nodeList[i%3] = new List<string>();

            }

            nodeList[i%3].Add(list[i]);

        }

        foreach(var nodes in nodeList) {

            foreach (var node in nodes) {

                var test = node;

            }

        }

        sw.Stop();

        Console.WriteLine(sw.Elapsed);

    }

}