1 /*
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2006 Daniel Le Berre
3 *
4 * Based on the original minisat specification from:
5 *
6 * An extensible SAT solver. Niklas E?n and Niklas S?rensson. Proceedings of the
7 * Sixth International Conference on Theory and Applications of Satisfiability
8 * Testing, LNCS 2919, pp 502-518, 2003.
9 *
10 * This library is free software; you can redistribute it and/or modify it under
11 * the terms of the GNU Lesser General Public License as published by the Free
12 * Software Foundation; either version 2.1 of the License, or (at your option)
13 * any later version.
14 *
15 * This library is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25 package org.sat4j.minisat.constraints.cnf;
26
27 import org.sat4j.minisat.core.ILits;
28 import org.sat4j.specs.IVecInt;
29
30 public class LearntWLClause extends WLClause {
31
32 public LearntWLClause(IVecInt ps, ILits voc) {
33 super(ps, voc);
34 }
35
36 /**
37 *
38 */
39 private static final long serialVersionUID = 1L;
40
41 /*
42 * (non-Javadoc)
43 *
44 * @see org.sat4j.minisat.constraints.cnf.WLClause#register()
45 */
46 public void register() {
47 assert lits.length > 1;
48 // prendre un deuxieme litt???ral ??? surveiller
49 int maxi = 1;
50 int maxlevel = voc.getLevel(lits[1]);
51 for (int i = 2; i < lits.length; i++) {
52 int level = voc.getLevel(lits[i]);
53 if (level > maxlevel) {
54 maxi = i;
55 maxlevel = level;
56 }
57 }
58 int l = lits[1];
59 lits[1] = lits[maxi];
60 lits[maxi] = l;
61
62 // ajoute la clause a la liste des clauses control???es.
63 voc.watch(lits[0] ^ 1, this);
64 voc.watch(lits[1] ^ 1, this);
65
66 }
67
68 public boolean learnt() {
69 return true;
70 }
71
72 public void setLearnt() {
73 // do nothing
74 }
75
76 }