spacenode.hh

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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Guido Tack <tack@gecode.org>
 *
 *  Copyright:
 *     Guido Tack, 2006
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#ifndef GECODE_GIST_SPACENODE_HH
#define GECODE_GIST_SPACENODE_HH

#include <gecode/gist/node.hh>
#include <gecode/kernel.hh>

namespace Gecode { namespace Gist {

  enum NodeStatus {
    SOLVED,       
    FAILED,       
    BRANCH,       
    UNDETERMINED, 
    STOP,         
    UNSTOP,       
  };

  static const unsigned int FIRSTBIT = 24; //< First free bit in status word
  static const unsigned int STATUSMASK = 7<<20; //< Mask for accessing status
  static const unsigned int MAXDISTANCE = (1<<20)-1; //< Maximum representable distance
  static const unsigned int DISTANCEMASK = (1<<20)-1; //< Mask for accessing distance

  class Statistics : public StatusStatistics {
  public:
    int solutions;
    int failures;
    int choices;
    int undetermined;
    int maxDepth;

    Statistics(void)
      : solutions(0), failures(0), choices(0), undetermined(1), maxDepth(0) {}
  };

  class SpaceNode;

  class BestNode {
  public:
    SpaceNode* s;
    BestNode(SpaceNode* s0);
  };

  class SpaceNode : public Node {
  protected:
    Space* copy;
  protected:
    const Choice* choice;

    unsigned int nstatus;

    void setDistance(unsigned int d);

    unsigned int getDistance(void) const;

    void setFlag(int flag, bool value);

    bool getFlag(int flag) const;

    enum SpaceNodeFlags {
      HASOPENCHILDREN = FIRSTBIT,
      HASFAILEDCHILDREN,
      HASSOLVEDCHILDREN
    };
    static const int LASTBIT = HASSOLVEDCHILDREN;

  private:
    void setHasOpenChildren(bool b);
    void setHasFailedChildren(bool b);
    void setHasSolvedChildren(bool b);

    int recompute(NodeAllocator& na,
                  BestNode* curBest, int c_d, int a_d);

    void closeChild(const NodeAllocator& na,
                    bool hadFailures, bool hadSolutions);
  protected:
    void setStatus(NodeStatus s);
    void acquireSpace(NodeAllocator& na,
                      BestNode* curBest, int c_d, int a_d);
  public:
    SpaceNode(int p);
    SpaceNode(Space* root);

    Space* getSpace(NodeAllocator& na,
                    BestNode* curBest, int c_d, int a_d);

    const Space* getWorkingSpace(void) const;

    void purge(const NodeAllocator& na);

    void dispose(void);

    bool isCurrentBest(BestNode* curBest);

    int getNumberOfChildNodes(NodeAllocator& na,
                              BestNode* curBest,
                              Statistics& stats,
                              int c_d, int a_d);

    NodeStatus getStatus(void) const;

    bool isOpen(void);
    bool hasFailedChildren(void);
    bool hasSolvedChildren(void);
    bool hasOpenChildren(void);
    int getNoOfOpenChildren(const NodeAllocator& na);
    void setNoOfOpenChildren(int n);
    bool hasCopy(void);
    bool hasWorkingSpace(void);

    int getAlternative(const NodeAllocator& na) const;
    const Choice* getChoice(void);
  };

}}

#endif

// STATISTICS: gist-any