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.cnf;
29
30 import org.sat4j.minisat.core.ILits;
31 import org.sat4j.specs.IVecInt;
32
33 public final class LearntWLClause extends WLClause {
34
35 public LearntWLClause(IVecInt ps, ILits voc) {
36 super(ps, voc);
37 }
38
39 /**
40 *
41 */
42 private static final long serialVersionUID = 1L;
43
44 /*
45 * (non-Javadoc)
46 *
47 * @see org.sat4j.minisat.constraints.cnf.WLClause#register()
48 */
49 public void register() {
50 assert lits.length > 1;
51 // prendre un deuxieme litt???ral ??? surveiller
52 int maxi = 1;
53 int maxlevel = voc.getLevel(lits[1]);
54 for (int i = 2; i < lits.length; i++) {
55 int level = voc.getLevel(lits[i]);
56 if (level > maxlevel) {
57 maxi = i;
58 maxlevel = level;
59 }
60 }
61 int l = lits[1];
62 lits[1] = lits[maxi];
63 lits[maxi] = l;
64
65 // ajoute la clause a la liste des clauses control???es.
66 voc.watch(lits[0] ^ 1, this);
67 voc.watch(lits[1] ^ 1, this);
68
69 }
70
71 public boolean learnt() {
72 return true;
73 }
74
75 public void setLearnt() {
76 // do nothing
77 }
78
79 /**
80 * @since 2.1
81 */
82 public void forwardActivity(double claInc) {
83
84 }
85
86 /**
87 * @param claInc
88 */
89 public void incActivity(double claInc) {
90 activity += claInc;
91 }
92 }