astar_state.h

00001 
00002 /***************************************************************************
00003  *  astar_state.h - Abstract class of a astar state.
00004  *
00005  *  Generated: Mon Sep 15 18:48:00 2002
00006  *  Copyright  2002-2007  Stefan Jacobs, Martin Liebenberg
00007  *
00008  ****************************************************************************/
00009 
00010 /*  This program is free software; you can redistribute it and/or modify
00011  *  it under the terms of the GNU General Public License as published by
00012  *  the Free Software Foundation; either version 2 of the License, or
00013  *  (at your option) any later version. A runtime exception applies to
00014  *  this software (see LICENSE.GPL_WRE file mentioned below for details).
00015  *
00016  *  This program is distributed in the hope that it will be useful,
00017  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  *  GNU Library General Public License for more details.
00020  *
00021  *  Read the full text in the LICENSE.GPL_WRE file in the doc directory.
00022  */
00023 
00024 #ifndef _ASTAR_ABSTRACT_STATE_H_
00025 #define _ASTAR_ABSTRACT_STATE_H_
00026 
00027 #include <vector>
00028 
00029 namespace fawkes {
00030 
00031 /** @class AStarState <utils/search/astar_state.h>
00032  *  This is the abstract(!) class for an A* State.
00033  * 
00034  * @author Stefan Jacobs
00035  */
00036 class AStarState
00037 {
00038  public:
00039   
00040   /** Constructor. */
00041   AStarState() {};
00042   
00043   /** Destructor. */
00044   virtual ~AStarState() {};
00045 
00046   
00047   // ***** You have to implement the following 4 methods! ***** //
00048   // ***** ============================================== ***** //
00049   
00050   /** Generates a unique key for this state.
00051    * There has to be a unique key for each state (fast closed list -> bottleneck!)
00052    * @return unique long key
00053    */
00054   virtual long calculateKey() = 0;
00055   
00056   /** Estimate the heuristic cost to the goal.
00057    * @return estimated cost as double
00058    */
00059   virtual double estimate() = 0;
00060   
00061   /** Check, wether we reached a goal or not.
00062    * @return true, if this state is a goal, else false
00063    */
00064   virtual bool isGoal() = 0;
00065   
00066   /** Generate all successors and put them to this vector.
00067    *  @return a vector of pointers of AStarState to a successor
00068    */
00069   virtual std::vector< AStarState * > generateChildren() = 0;
00070 
00071   /** Predecessor. */
00072   AStarState *father;
00073 
00074   /** Past cost. */
00075   double pastCost;
00076   /** Total estimated cost. */
00077   double totalEstimatedCost;
00078   
00079   /** The unique key of this state. */
00080   long key;
00081 };
00082 
00083 } // end namespace fawkes
00084 
00085 #endif