/*
 * queue.h
 */

#ifndef QUEUE_H
#define QUEUE_H

#include "point.h"

typedef COORD queueElem[3];

typedef struct queueNode {
  queueElem e;
  struct queueNode* next;
} QNODE;

typedef QNODE* QUEUE;

//create a head , point it to NULL and return a pointer to the head of the list
QUEUE Q_init();

// insert element e at the head of the list by copying its contents into QNODE
void Q_insert_elem_head(QUEUE h, queueElem e);

// insert QNODE at head of the list
void Q_insert_qnode_head(QUEUE h, QNODE* n);

// remove the first element in the queue
QNODE* Q_remove_first(QUEUE h);

// remove the first element and free it from memory
short Q_delete_first(QUEUE h);

void Q_free_queue(QUEUE h);

//returns first element after head
QNODE* Q_first(QUEUE h);

//returns p->next
QNODE* Q_next(QUEUE h, QNODE* p);

//returns 1 if p is the last element in the queue else 0
short Q_isEnd(QUEUE h, QNODE* p);
 
#endif // QUEUE_H