1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
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 * Contributors:
28 * CRIL - initial API and implementation
29 *******************************************************************************/
30 package org.sat4j.pb.constraints;
31
32 import org.sat4j.minisat.constraints.cnf.LearntBinaryClause;
33 import org.sat4j.minisat.constraints.cnf.LearntHTClause;
34 import org.sat4j.minisat.constraints.cnf.OriginalBinaryClause;
35 import org.sat4j.minisat.constraints.cnf.OriginalHTClause;
36 import org.sat4j.minisat.constraints.cnf.UnitClause;
37 import org.sat4j.minisat.core.Constr;
38 import org.sat4j.minisat.core.ILits;
39 import org.sat4j.specs.IVecInt;
40 import org.sat4j.specs.UnitPropagationListener;
41
42 public class UnitBinaryHTClauseConstructor implements IClauseConstructor {
43
44 public Constr constructClause(UnitPropagationListener solver, ILits voc,
45 IVecInt v) {
46 if (v == null) {
47 // tautological clause
48 return null;
49 }
50 if (v.size() == 1) {
51 return new UnitClause(v.last());
52 }
53 if (v.size() == 2) {
54 return OriginalBinaryClause.brandNewClause(solver, voc, v);
55 }
56 return OriginalHTClause.brandNewClause(solver, voc, v);
57 }
58
59 public Constr constructLearntClause(ILits voc, IVecInt literals) {
60 if (literals.size() == 1) {
61 return new UnitClause(literals.last());
62 }
63 if (literals.size() == 2) {
64 return new LearntBinaryClause(literals, voc);
65 }
66 return new LearntHTClause(literals, voc);
67 }
68
69 }