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.minisat.constraints;
31
32 import org.sat4j.minisat.constraints.card.AtLeast;
33 import org.sat4j.minisat.constraints.cnf.Clauses;
34 import org.sat4j.minisat.constraints.cnf.LearntBinaryClause;
35 import org.sat4j.minisat.constraints.cnf.LearntHTClause;
36 import org.sat4j.minisat.constraints.cnf.Lits;
37 import org.sat4j.minisat.constraints.cnf.OriginalBinaryClause;
38 import org.sat4j.minisat.constraints.cnf.OriginalHTClause;
39 import org.sat4j.minisat.constraints.cnf.UnitClause;
40 import org.sat4j.minisat.core.Constr;
41 import org.sat4j.minisat.core.ILits;
42 import org.sat4j.specs.ContradictionException;
43 import org.sat4j.specs.IVecInt;
44
45 /**
46 * Uses specific data structure for cardinality constraints.
47 *
48 * @author leberre
49 * @since 2.1
50 */
51 public class MixedDataStructureDanielHT extends AbstractDataStructureFactory {
52
53 private static final long serialVersionUID = 1L;
54
55 /*
56 * (non-Javadoc)
57 *
58 * @see
59 * org.sat4j.minisat.DataStructureFactory#createCardinalityConstraint(org
60 * .sat4j.datatype.VecInt, int)
61 */
62 @Override
63 public Constr createCardinalityConstraint(IVecInt literals, int degree)
64 throws ContradictionException {
65 return AtLeast.atLeastNew(this.solver, getVocabulary(), literals,
66 degree);
67 }
68
69 /*
70 * (non-Javadoc)
71 *
72 * @see
73 * org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype
74 * .VecInt)
75 */
76 public Constr createClause(IVecInt literals) throws ContradictionException {
77 IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), this.solver);
78 if (v == null) {
79 // tautological clause
80 return null;
81 }
82 if (v.size() == 1) {
83 return new UnitClause(v.last());
84 }
85 if (v.size() == 2) {
86 return OriginalBinaryClause.brandNewClause(this.solver,
87 getVocabulary(), v);
88 }
89 return OriginalHTClause.brandNewClause(this.solver, getVocabulary(), v);
90 }
91
92 public Constr createUnregisteredClause(IVecInt literals) {
93 if (literals.size() == 1) {
94 return new UnitClause(literals.last());
95 }
96 if (literals.size() == 2) {
97 return new LearntBinaryClause(literals, getVocabulary());
98 }
99 return new LearntHTClause(literals, getVocabulary());
100 }
101
102 @Override
103 protected ILits createLits() {
104 return new Lits();
105 }
106 }