using System;

using System.Threading;

​

public class Program

{

    public static void Main()

    {

        var myQueue = new Queue(3);

        //myQueue.Dequeue();

        myQueue.Enqueue(1);

        myQueue.Enqueue(2);

        myQueue.Enqueue(3);

        //myQueue.Enqueue(4);

        myQueue.Dequeue();

        myQueue.Dequeue();

        myQueue.Dequeue();

        //myQueue.Dequeue();

        myQueue.Enqueue(1);

    }

}

​

public class Queue

{

    int[] values;

    int head;

    int tail;

    Mutex mutex;

    public Queue(int size)

    {

        values = new int[size];     

        head = -1;

        tail = 0;

        mutex = new Mutex();

    }

    public void Enqueue(int value)

    {

        if(tail != head)

        {

            values[tail] = value;

            if(head == -1)

                head = tail;

            tail = (tail + 1) % values.Length;

        }

        else

        {

            throw new ApplicationException("Queue Full");

        }

    }

    public int Dequeue()

    {

        if(head == -1)

            throw new ApplicationException("Queue Empty");

        var temp = values[head];

        head = (head + 1) % values.Length;

        if(head == tail)

            head = -1;

        return temp;

    }

}