/*******************************************************************************
* SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU Lesser General Public License Version 2.1 or later (the
* "LGPL"), in which case the provisions of the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of the LGPL, and not to allow others to use your version of
* this file under the terms of the EPL, indicate your decision by deleting
* the provisions above and replace them with the notice and other provisions
* required by the LGPL. If you do not delete the provisions above, a recipient
* may use your version of this file under the terms of the EPL or the LGPL.
*
* Based on the original MiniSat specification from:
*
* An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
* Sixth International Conference on Theory and Applications of Satisfiability
* Testing, LNCS 2919, pp 502-518, 2003.
*
* See www.minisat.se for the original solver in C++.
*
*******************************************************************************/
package org.sat4j.minisat.constraints;
import org.sat4j.minisat.constraints.cnf.Clauses;
import org.sat4j.minisat.constraints.cnf.LearntBinaryClause;
import org.sat4j.minisat.constraints.cnf.LearntHTClause;
import org.sat4j.minisat.constraints.cnf.Lits;
import org.sat4j.minisat.constraints.cnf.MixableCBClause;
import org.sat4j.minisat.constraints.cnf.UnitClause;
import org.sat4j.minisat.core.Constr;
import org.sat4j.minisat.core.ILits;
import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.IVecInt;
/**
* Uses Counter Based data strudture for the original clausal in the database
* and uses Head Tail Data structure for learned clauses.
*
* @author leberre
*/
public class ClausalDataStructureCBHT extends AbstractDataStructureFactory<ILits> {
private static final long serialVersionUID = 1L;
/*
* (non-Javadoc)
*
* @see org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype.VecInt)
*/
public Constr createClause(IVecInt literals) throws ContradictionException {
IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), solver);
if (v == null)
return null;
return MixableCBClause.brandNewClause(solver, getVocabulary(), v);
}
public Constr createUnregisteredClause(IVecInt literals) {
if (literals.size()==1) {
return new UnitClause(literals.last());
}
if (literals.size() == 2) {
return new LearntBinaryClause(literals,getVocabulary());
}
return new LearntHTClause(literals, getVocabulary());
}
@Override
protected ILits createLits() {
return new Lits();
}
}