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.core.Vec;
33 import org.sat4j.core.VecInt;
34 import org.sat4j.minisat.core.ILits;
35 import org.sat4j.minisat.core.UnitPropagationListener;
36 import org.sat4j.specs.ContradictionException;
37 import org.sat4j.specs.IVec;
38 import org.sat4j.specs.IVecInt;
39
40 public class PuebloMinWatchPb extends MinWatchPb {
41
42 private static final long serialVersionUID = 1L;
43
44 /**
45 * Constructeur de base des contraintes
46 *
47 * @param voc
48 * Informations sur le vocabulaire employ???
49 * @param ps
50 * Liste des litt???raux
51 * @param weightedLits
52 * Liste des coefficients
53 * @param moreThan
54 * Indication sur le comparateur
55 * @param degree
56 * Stockage du degr??? de la contrainte
57 */
58 private PuebloMinWatchPb(ILits voc, IDataStructurePB mpb) {
59
60 super(voc, mpb);
61 }
62
63 /**
64 * @param s
65 * outil pour la propagation des litt???raux
66 * @param ps
67 * liste des litt???raux de la nouvelle contrainte
68 * @param coefs
69 * liste des coefficients des litt???raux de la contrainte
70 * @param moreThan
71 * d???termine si c'est une sup???rieure ou ???gal ??? l'origine
72 * @param degree
73 * fournit le degr??? de la contrainte
74 * @return une nouvelle clause si tout va bien, ou null si un conflit est
75 * d???tect???
76 */
77 public static PuebloMinWatchPb minWatchPbNew(UnitPropagationListener s,
78 ILits voc, IVecInt ps, IVecInt coefs, boolean moreThan, int degree)
79 throws ContradictionException {
80 return minWatchPbNew(s, voc, ps, Pseudos.toVecBigInt(coefs), moreThan,
81 BigInteger.valueOf(degree));
82 }
83
84 /**
85 * @param s
86 * outil pour la propagation des litt???raux
87 * @param ps
88 * liste des litt???raux de la nouvelle contrainte
89 * @param coefs
90 * liste des coefficients des litt???raux de la contrainte
91 * @param moreThan
92 * d???termine si c'est une sup???rieure ou ???gal ??? l'origine
93 * @param degree
94 * fournit le degr??? de la contrainte
95 * @return une nouvelle clause si tout va bien, ou null si un conflit est
96 * d???tect???
97 */
98 public static PuebloMinWatchPb minWatchPbNew(UnitPropagationListener s,
99 ILits voc, IVecInt ps, IVec<BigInteger> coefs, boolean moreThan,
100 BigInteger degree) throws ContradictionException {
101 // Il ne faut pas modifier les param?tres
102 VecInt litsVec = new VecInt(ps.size());
103 IVec<BigInteger> coefsVec = new Vec<BigInteger>(coefs.size());
104 ps.copyTo(litsVec);
105 coefs.copyTo(coefsVec);
106
107 // Ajouter les simplifications quand la structure sera d???finitive
108 IDataStructurePB mpb = Pseudos.niceParameters(litsVec, coefsVec, moreThan,
109 degree, voc);
110 PuebloMinWatchPb outclause = new PuebloMinWatchPb(voc, mpb);
111
112 if (outclause.degree.signum() <= 0) {
113 return null;
114 }
115
116 outclause.computeWatches();
117
118 outclause.computePropagation(s);
119
120 return outclause;
121
122 }
123
124 public static PuebloMinWatchPb minWatchPbNew(UnitPropagationListener s,
125 ILits voc, IDataStructurePB mpb) throws ContradictionException {
126 PuebloMinWatchPb outclause = new PuebloMinWatchPb(voc, mpb);
127
128 if (outclause.degree.signum() <= 0) {
129 return null;
130 }
131
132 outclause.computeWatches();
133
134 outclause.computePropagation(s);
135
136 return outclause;
137
138 }
139
140 /**
141 *
142 */
143 public static WatchPb watchPbNew(ILits voc, IVecInt lits, IVecInt coefs,
144 boolean moreThan, int degree) {
145 return watchPbNew(voc, lits, Pseudos.toVecBigInt(coefs), moreThan,
146 BigInteger.valueOf(degree));
147 }
148
149 /**
150 *
151 */
152 public static WatchPb watchPbNew(ILits voc, IVecInt lits,
153 IVec<BigInteger> coefs, boolean moreThan, BigInteger degree) {
154 IDataStructurePB mpb = null;
155 mpb = Pseudos.niceCheckedParameters(lits, coefs, moreThan, degree, voc);
156 return new PuebloMinWatchPb(voc, mpb);
157 }
158
159 public static WatchPb normalizedWatchPbNew(ILits voc, IDataStructurePB mpb) {
160 return new PuebloMinWatchPb(voc, mpb);
161 }
162
163 @Override
164 protected BigInteger maximalCoefficient(int pIndice) {
165 return coefs[0];
166 }
167
168 @Override
169 protected BigInteger updateWatched(BigInteger mc, int pIndice) {
170 BigInteger maxCoef = mc;
171 if (watchingCount < size()) {
172 BigInteger upWatchCumul = watchCumul.subtract(coefs[pIndice]);
173 BigInteger borneSup = degree.add(maxCoef);
174 for (int ind = 0; ind < lits.length
175 && upWatchCumul.compareTo(borneSup) < 0; ind++) {
176 if (!voc.isFalsified(lits[ind]) && !watched[ind]) {
177 upWatchCumul = upWatchCumul.add(coefs[ind]);
178 watched[ind] = true;
179 assert watchingCount < size();
180 watching[watchingCount++] = ind;
181 voc.attach(lits[ind] ^ 1, this);
182 }
183 }
184 watchCumul = upWatchCumul.add(coefs[pIndice]);
185 }
186 return maxCoef;
187 }
188
189 }