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.cnf;
31
32 import static org.sat4j.core.LiteralsUtils.neg;
33
34 import org.sat4j.minisat.core.ILits;
35 import org.sat4j.specs.IVecInt;
36
37 /**
38 * @author daniel
39 * @since 2.1
40 */
41 public class LearntHTClause extends HTClause {
42
43 public LearntHTClause(IVecInt ps, ILits voc) {
44 super(ps, voc);
45 }
46
47 /**
48 *
49 */
50 private static final long serialVersionUID = 1L;
51
52 /*
53 * (non-Javadoc)
54 *
55 * @see org.sat4j.minisat.constraints.cnf.WLClause#register()
56 */
57 public void register() {
58 // looking for the literal to put in tail
59 if (this.middleLits.length > 0) {
60 int maxi = 0;
61 int maxlevel = this.voc.getLevel(this.middleLits[0]);
62 for (int i = 1; i < this.middleLits.length; i++) {
63 int level = this.voc.getLevel(this.middleLits[i]);
64 if (level > maxlevel) {
65 maxi = i;
66 maxlevel = level;
67 }
68 }
69 if (maxlevel > this.voc.getLevel(this.tail)) {
70 int l = this.tail;
71 this.tail = this.middleLits[maxi];
72 this.middleLits[maxi] = l;
73 }
74 }
75 // attach both head and tail literals.
76 this.voc.watch(neg(this.head), this);
77 this.voc.watch(neg(this.tail), this);
78
79 }
80
81 public boolean learnt() {
82 return true;
83 }
84
85 public void setLearnt() {
86 // do nothing
87 }
88
89 public void forwardActivity(double claInc) {
90
91 }
92
93 /**
94 * @param claInc
95 */
96 public void incActivity(double claInc) {
97 this.activity += claInc;
98 }
99
100 public void setActivity(double d) {
101 this.activity = d;
102 }
103 }