// C or C++ program for insertion and
// deletion in Circular Queue
#include<bits/stdc++.h>
using namespace std;

struct Queue
{
  // Initialize front and rear
  int rear, front;

  // Circular Queue
  int size;
  int *arr;

  Queue(int s)
  {
    front = rear = -1;
    size = s;
    arr = new int[s];
  }

  void enQueue(int value);
  int deQueue();
  void displayQueue();
};


/* Function to create Circular queue */
void Queue::enQueue(int value)
{
  if ((front == 0 && rear == size-1) ||
      (rear == (front-1)%(size-1)))
    {
      printf("Queue is Full\n");
      return;
    }

  else if (front == -1) /* Insert First Element */
    {
      front = rear = 0;
      arr[rear] = value;
    }

  else if (rear == size-1 && front != 0)
    {
      rear = 0;
      arr[rear] = value;
    }

  else
    {
      rear++;
      arr[rear] = value;
    }
}

// Function to delete element from Circular Queue
int Queue::deQueue()
{
  if (front == -1)
    {
      printf("Queue is Empty\n");
      return INT_MIN;
    }

  int data = arr[front];
  arr[front] = -1;
  if (front == rear)
    {
      front = -1;
      rear = -1;
    }
  else if (front == size-1)
    front = 0;
  else
    front++;

  return data;
}

// Function displaying the elements
// of Circular Queue
void Queue::displayQueue()
{
  if (front == -1)
    {
      printf("Queue is Empty\n");
      return;
    }
  printf("Elements in Circular Queue are: ");
  if (rear >= front)
    {
      for (int i = front; i <= rear; i++)
	printf("%d ",arr[i]);
    }
  else
    {
      for (int i = front; i < size; i++)
	printf("%d ", arr[i]);

      for (int i = 0; i <= rear; i++)
	printf("%d ", arr[i]);
    }
  printf("\n");
}

/* Driver of the program */
int main()
{
  Queue q(5);

  // Inserting elements in Circular Queue
  fprintf(stdout, "inserting %d\n", 1);
  q.enQueue(1);
  q.displayQueue();

  fprintf(stdout, "inserting %d\n", 2);  
  q.enQueue(2);
  q.displayQueue();

  fprintf(stdout, "inserting %d\n", 3);
  q.enQueue(3);
  q.displayQueue();

  fprintf(stdout, "inserting %d\n", 4);
  q.enQueue(4);
  q.displayQueue();

  fprintf(stdout, "inserting %d\n", 5);
  q.enQueue(5);
  q.displayQueue();

  fprintf(stdout, "inserting %d\n", 6);
  q.enQueue(6);
  q.displayQueue();

  /*
  // Display elements present in Circular Queue


  // Deleting elements from Circular Queue
  printf("\nDeleted value = %d", q.deQueue());
  printf("\nDeleted value = %d", q.deQueue());

  q.displayQueue();

  q.enQueue(9);
  q.enQueue(20);
  q.enQueue(5);

  q.displayQueue();

  q.enQueue(20);
  */


  return 0;
}