SizeMaxIndepSetAlg.h

Go to the documentation of this file.

/* Frobby: Software for monomial ideal computations.
   Copyright (C) 2009 Bjarke Hammersholt Roune (www.broune.com)
 
   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, see http://www.gnu.org/licenses/.
*/
#ifndef SIZE_MAX_INDEP_SET_ALG
#define SIZE_MAX_INDEP_SET_ALG
 
#include "Ideal.h"
 
class SizeMaxIndepSetAlg {
 public:
  void run(Ideal& ideal);
 
  mpz_class getMaxIndepSetSize();
 
 private:
  enum VarState {
    IsMaybeInSet = 0,
    IsNotInSet = 1,
    IsInSet = 2
  };
 
  bool isIndependentIncludingMaybe(size_t pos);
 
  bool couldBeDependence(size_t pos, size_t nextPos, size_t& maybeCount);
 
  void recurse(size_t pos, size_t excluded);
 
  size_t _varCount;
 
  size_t _minExcluded;
 
  vector<VarState> _state;
 
  vector<vector<size_t> > _undo;
 
  bool _noIndependentSets;
 
  vector<size_t> _edges;
 
  size_t _endPos;
};
 
#endif