import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Vector;

/**
 * BestFirstSearcher.java - a simple implementation of best-first
 * search.
 *
 * @author Todd Neller
 * @version 1.0
 *

Copyright (C) 2004 Todd Neller

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.

Information about the GNU General Public License is available online at:
  http://www.gnu.org/licenses/
To receive a copy of the GNU General Public License, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.

 */

public class BestFirstSearcher extends HSearcher {

    /**
     * <code>comparator</code> - the comparator that orders nodes in
     * the search priority queue, determining what is "best" in
     * best-first search.
     */
    private Comparator<HSearchNode> comparator;

    /**
     * Creates a new <code>BestFirstSearcher</code> instance with the
     * given comparator to order HSearchNodes in the Priority Queue.
     *
     * @param comparator a <code>Comparator</code> value - determiner
     * of what is "best" in the best-first search.
     */
    public BestFirstSearcher(Comparator<HSearchNode> comparator) 
    {
	this.comparator = comparator;
    }

    /**
     * <code>search</code> - given an initial node, perform best-first
     * search.
     *
     * @param rootNode a <code>HSearchNode</code> value - the initial node
     * @return a <code>boolean</code> value - whether or not goal node
     * was found */
    public boolean search(HSearchNode rootNode) {
	// IMPLEMENT:

	// Initialize search variables.
	
	// Main search loop:
	while (true) {
	
	    // If the search queue is empty, return with failure
	    // (false).

	    // Otherwise get the next search node from the front of
	    // the queue and increment the nodeCount.

	    // If the search node is a goal node, store it and return
	    // with success (true).

	    // Otherwise, expand the node and insert each of its
	    // children into the queue.
	}

    }    

}// BestFirstSearcher