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 pseudo boolean algorithms described in:
20 * A fast pseudo-Boolean constraint solver Chai, D.; Kuehlmann, A.
21 * Computer-Aided Design of Integrated Circuits and Systems, IEEE Transactions on
22 * Volume 24, Issue 3, March 2005 Page(s): 305 - 317
23 *
24 * and
25 * Heidi E. Dixon, 2004. Automating Pseudo-Boolean Inference within a DPLL
26 * Framework. Ph.D. Dissertation, University of Oregon.
27 *******************************************************************************/
28 package org.sat4j.pb.constraints.pb;
29
30 import java.math.BigInteger;
31
32 import org.sat4j.minisat.core.ILits;
33 import org.sat4j.minisat.core.UnitPropagationListener;
34 import org.sat4j.specs.ContradictionException;
35
36 public class PuebloMinWatchPb extends MinWatchPb {
37
38 private static final long serialVersionUID = 1L;
39
40 /**
41 * Constructeur de base des contraintes
42 *
43 * @param voc
44 * Informations sur le vocabulaire employ???
45 * @param ps
46 * Liste des litt???raux
47 * @param weightedLits
48 * Liste des coefficients
49 * @param moreThan
50 * Indication sur le comparateur
51 * @param degree
52 * Stockage du degr??? de la contrainte
53 */
54 private PuebloMinWatchPb(ILits voc, int[] lits, BigInteger[] coefs,
55 BigInteger degree) {
56 super(voc, lits, coefs, degree);
57 }
58
59 private PuebloMinWatchPb(ILits voc, IDataStructurePB mpb) {
60
61 super(voc, mpb);
62 }
63
64 /**
65 * @param s
66 * a unit propagation listener
67 * @param voc
68 * the vocabulary
69 * @param lits
70 * the literals
71 * @param coefs
72 * the coefficients
73 * @param degree
74 * the degree of the constraint to normalize.
75 * @return a new PB constraint or null if a trivial inconsistency is
76 * detected.
77 */
78 public static PuebloMinWatchPb normalizedMinWatchPbNew(
79 UnitPropagationListener s, ILits voc, int[] lits,
80 BigInteger[] coefs, BigInteger degree)
81 throws ContradictionException {
82 // Il ne faut pas modifier les param?tres
83 PuebloMinWatchPb outclause = new PuebloMinWatchPb(voc, lits, coefs,
84 degree);
85
86 if (outclause.degree.signum() <= 0) {
87 return null;
88 }
89
90 outclause.computeWatches();
91
92 outclause.computePropagation(s);
93
94 return outclause;
95
96 }
97
98 public static WatchPb normalizedWatchPbNew(ILits voc, IDataStructurePB mpb) {
99 return new PuebloMinWatchPb(voc, mpb);
100 }
101
102 @Override
103 protected BigInteger maximalCoefficient(int pIndice) {
104 return coefs[0];
105 }
106
107 @Override
108 protected BigInteger updateWatched(BigInteger mc, int pIndice) {
109 BigInteger maxCoef = mc;
110 if (watchingCount < size()) {
111 BigInteger upWatchCumul = watchCumul.subtract(coefs[pIndice]);
112 BigInteger borneSup = degree.add(maxCoef);
113 for (int ind = 0; ind < lits.length
114 && upWatchCumul.compareTo(borneSup) < 0; ind++) {
115 if (!voc.isFalsified(lits[ind]) && !watched[ind]) {
116 upWatchCumul = upWatchCumul.add(coefs[ind]);
117 watched[ind] = true;
118 assert watchingCount < size();
119 watching[watchingCount++] = ind;
120 voc.watch(lits[ind] ^ 1, this);
121 }
122 }
123 watchCumul = upWatchCumul.add(coefs[pIndice]);
124 }
125 return maxCoef;
126 }
127
128 }