Solution to the Dining Philosophers problem - Solves the deadlock problem by alternating the order the philosophers select their chopsticks.

PhilosophersWithOrderAlteration

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

namespace DiningPhilosophers
{
    class Program
    {
        static int philisopherNumber = 5;
        static Task[] philosiphers;
        static SemaphoreSlim[] chopsticks;

        static void Main(string[] args)
        {
            philosiphers = new Task[philisopherNumber];
            chopsticks = new SemaphoreSlim[philisopherNumber];

            for (int i = 0; i < philisopherNumber; ++i)
            {
                philosiphers[i] = GenerateNewPhilosopher(i);
                chopsticks[i] = new SemaphoreSlim(1);
            }

            Task.WaitAll(philosiphers);
            Console.WriteLine("Finished eating. HUZZAH!");
            Console.ReadLine();
        }

        private static Task GenerateNewPhilosopher(int philosipherIndex)
        {
            return Task.Run(() =>
            {

                for (int i = 0; i < 100; ++i)
                {
                    Console.WriteLine($"Phil {philosipherIndex}: Attempting to get food");

                    var chopstick1 = GetChopstickIndex(philosipherIndex);
                    var chopstick2 = GetChopstickIndex(philosipherIndex + 1);
                    var chopsticksList = new List<int>() { chopstick1, chopstick2 }.OrderBy(index => index).ToList();
                    foreach (var chopstickIndex in chopsticksList)
                    {
                        chopsticks[chopstickIndex].Wait();
                    }

                    Console.WriteLine($"Phil {philosipherIndex}: Eating");
                    Task.Delay(100); // NOM NOM NOM

                    chopsticks[GetChopstickIndex(philosipherIndex)].Release();
                    chopsticks[GetChopstickIndex(philosipherIndex + 1)].Release();
                }
            });
        }

        private static int GetChopstickIndex(int index)
        {
            return index % philisopherNumber;
        }
    }
}