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.pb.constraints.pb;
29
30 import java.math.BigInteger;
31
32 import org.sat4j.minisat.constraints.cnf.BinaryClause;
33 import org.sat4j.minisat.core.ILits;
34 import org.sat4j.minisat.core.UnitPropagationListener;
35 import org.sat4j.specs.IVecInt;
36
37 public class BinaryClausePB extends BinaryClause implements PBConstr {
38
39 /**
40 *
41 */
42 private static final long serialVersionUID = 1L;
43
44 public BinaryClausePB(IVecInt ps, ILits voc) {
45 super(ps, voc);
46 }
47
48 private boolean learnt = false;
49
50 public IVecInt computeAnImpliedClause() {
51 return null;
52 }
53
54 public BigInteger getCoef(int literal) {
55 return BigInteger.ONE;
56 }
57
58 public BigInteger[] getCoefs() {
59 return new BigInteger [] {BigInteger.ONE,BigInteger.ONE};
60 }
61
62 public BigInteger getDegree() {
63 return BigInteger.ONE;
64 }
65
66 public void setLearnt() {
67 learnt = true;
68 }
69
70 public boolean learnt() {
71 return learnt;
72 }
73
74 /**
75 * Creates a brand new clause, presumably from external data. Performs all
76 * sanity checks.
77 *
78 * @param s
79 * the object responsible for unit propagation
80 * @param voc
81 * the vocabulary
82 * @param literals
83 * the literals to store in the clause (size should be two)
84 * @return the created clause or null if the clause should be ignored
85 * (tautology for example)
86 */
87 public static BinaryClausePB brandNewClause(UnitPropagationListener s,
88 ILits voc, IVecInt literals) {
89 BinaryClausePB c = new BinaryClausePB(literals, voc);
90 c.register();
91 return c;
92 }
93
94 }