1 /******************************************************************************* 2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre 3 * 4 * All rights reserved. This program and the accompanying materials 5 * are made available under the terms of the Eclipse Public License v1.0 6 * which accompanies this distribution, and is available at 7 * http://www.eclipse.org/legal/epl-v10.html 8 * 9 * Alternatively, the contents of this file may be used under the terms of 10 * either the GNU Lesser General Public License Version 2.1 or later (the 11 * "LGPL"), in which case the provisions of the LGPL are applicable instead 12 * of those above. If you wish to allow use of your version of this file only 13 * under the terms of the LGPL, and not to allow others to use your version of 14 * this file under the terms of the EPL, indicate your decision by deleting 15 * the provisions above and replace them with the notice and other provisions 16 * required by the LGPL. If you do not delete the provisions above, a recipient 17 * may use your version of this file under the terms of the EPL or the LGPL. 18 * 19 * Based on the original MiniSat specification from: 20 * 21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the 22 * Sixth International Conference on Theory and Applications of Satisfiability 23 * Testing, LNCS 2919, pp 502-518, 2003. 24 * 25 * See www.minisat.se for the original solver in C++. 26 * 27 *******************************************************************************/ 28 package org.sat4j.minisat.constraints; 29 30 import org.sat4j.minisat.constraints.cnf.Clauses; 31 import org.sat4j.minisat.constraints.cnf.LearntHTClause; 32 import org.sat4j.minisat.constraints.cnf.Lits; 33 import org.sat4j.minisat.constraints.cnf.OriginalHTClause; 34 import org.sat4j.minisat.constraints.cnf.UnitClause; 35 import org.sat4j.minisat.core.Constr; 36 import org.sat4j.minisat.core.ILits; 37 import org.sat4j.specs.ContradictionException; 38 import org.sat4j.specs.IVecInt; 39 40 /** 41 * Uses Head Tail data structure for both original clauses and learned clauses. 42 * 43 * @author leberre 44 */ 45 public class ClausalDataStructureHT extends AbstractDataStructureFactory<ILits> { 46 47 private static final long serialVersionUID = 1L; 48 49 /* 50 * (non-Javadoc) 51 * 52 * @see org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype.VecInt) 53 */ 54 public Constr createClause(IVecInt literals) throws ContradictionException { 55 IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), solver); 56 if (v == null) 57 return null; 58 return OriginalHTClause.brandNewClause(solver, getVocabulary(), v); 59 } 60 61 public Constr createUnregisteredClause(IVecInt literals) { 62 if (literals.size()==1) { 63 return new UnitClause(literals.last()); 64 } 65 return new LearntHTClause(literals, getVocabulary()); 66 } 67 68 @Override 69 protected ILits createLits() { 70 return new Lits(); 71 } 72 }