// Online C# Editor for free

// Write, Edit and Run your C# code using C# Online Compiler

​

using System;

using System.Linq;

using System.Collections.Generic;

using System.Threading;

using System.Threading.Tasks;

​

public enum State

{

    Eating, Thinking,

}

​

internal class Program

{

    private static State[] _states;

    private static bool[] _forks;

​

    private static void Setup(int n)

    {

        _states = Enumerable.Repeat(State.Thinking, n).ToArray();

        _forks = Enumerable.Repeat(true, n).ToArray();

    }

​

    private static void Run(int id)

    {

        var random = new Random();

        while (true)

        {

            var leftFork = (id - 1) % _forks.Length;

            var rightFork = (id + 1) % _forks.Length;

            // We need both forks available to be able to east

            if (!_forks[leftFork] || !_forks[rightFork]) continue;

            // Make sure updating of fork and state happens atomically, without concurrent read/update

            lock (_forks) lock(_states)

            {

                Console.WriteLine($"{id} is starting to eat");

                _forks[leftFork] = false;

                _forks[rightFork] = false;

                _states[id] = State.Eating;

            }

​

            Thread.Sleep(TimeSpan.FromSeconds(random.Next(1, 5)));

            // Make sure updating of fork and state happens atomically, without concurrent read/update

            lock (_forks) lock(_states)

            {

                Console.WriteLine($"{id} finished eating");

                _forks[leftFork] = true;

                _forks[rightFork] = true;

                _states[id] = State.Thinking;

            }

        }

    }

    public static void Main(string[] args)

    {

        const int count = 5;

        Setup(count);

        var tasks = new List<Task>();

​

        for (var i = 0; i < count; i++)

        {

            var icopy = i;

            tasks.Add(Task.Factory.StartNew(() => Run(icopy)));

        }

​

        Task.WaitAll(tasks.ToArray());

    }

}