/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Tao Ju
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef QUEUE_H
#define QUEUE_H

struct gridQueueEle
{
	int x, y, z;
	UCHAR dir ;
	gridQueueEle* next ;
};

class GridQueue
{
	gridQueueEle* head ;
	gridQueueEle* tail ;
	int numEles ;

public:

	GridQueue( )
	{
		head = NULL ;
		tail = NULL ;
		numEles = 0 ;
	}

	gridQueueEle* getHead( )
	{
		return head ;
	}

	int getNumElements( )
	{
		return numEles ;
	}


	void pushQueue( int st[3], int dir )
	{
		gridQueueEle* ele = new gridQueueEle ;
		ele->x = st[0] ;
		ele->y = st[1] ;
		ele->z = st[2] ;
		ele->dir = (UCHAR) dir ;
		ele->next = NULL ;
		if ( head == NULL )
		{
			head = ele ;
		}
		else
		{
			tail->next = ele ;
		}
		tail = ele ;
		numEles ++ ;
	}

	int popQueue( int st[3], int& dir )
	{
		if ( head == NULL )
		{
			return 0 ;
		}

		st[0] = head->x ;
		st[1] = head->y ;
		st[2] = head->z ;
		dir = (int) (head->dir) ;

		gridQueueEle* temp = head ;
		head = head->next ;
		delete temp ;

		if ( head == NULL )
		{
			tail = NULL ;
		}
		numEles -- ;

		return 1 ;
	}

};





#endif