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.constraints.card.AtLeast;
33 import org.sat4j.minisat.core.ILits;
34 import org.sat4j.minisat.core.UnitPropagationListener;
35 import org.sat4j.specs.ContradictionException;
36 import org.sat4j.specs.IVecInt;
37
38 public class AtLeastPB extends AtLeast implements PBConstr {
39
40 /**
41 *
42 */
43 private static final long serialVersionUID = 1L;
44
45 private final BigInteger degree;
46
47 private AtLeastPB(ILits voc, IVecInt ps, int degree) {
48 super(voc, ps, degree);
49 this.degree = BigInteger.valueOf(degree);
50 }
51
52 public static AtLeastPB atLeastNew(UnitPropagationListener s, ILits voc,
53 IVecInt ps, int n) throws ContradictionException {
54 int degree = niceParameters(s, voc, ps, n);
55 if (degree == 0)
56 return null;
57 return new AtLeastPB(voc, ps, degree);
58 }
59
60 public static AtLeastPB atLeastNew(ILits voc, IVecInt ps, int n) {
61 return new AtLeastPB(voc, ps, n);
62 }
63
64 public BigInteger getCoef(int literal) {
65 return BigInteger.ONE;
66 }
67
68 public BigInteger getDegree() {
69 return degree;
70 }
71
72 public ILits getVocabulary() {
73 return voc;
74 }
75
76 public int[] getLits() {
77 int[] tmp = new int[size()];
78 System.arraycopy(lits, 0, tmp, 0, size());
79 return tmp;
80 }
81
82 public BigInteger[] getCoefs() {
83 BigInteger[] tmp = new BigInteger[size()];
84 for (int i = 0; i < tmp.length; i++)
85 tmp[i] = BigInteger.ONE;
86 return tmp;
87 }
88
89 /**
90 *
91 */
92 private boolean learnt = false;
93
94 /**
95 * D?termine si la contrainte est apprise
96 *
97 * @return true si la contrainte est apprise, false sinon
98 * @see org.sat4j.specs.IConstr#learnt()
99 */
100 @Override
101 public boolean learnt() {
102 return learnt;
103 }
104
105 @Override
106 public void setLearnt() {
107 learnt = true;
108 }
109
110 @Override
111 public void register() {
112 assert learnt;
113 // countFalsified();
114 }
115
116 @Override
117 public void assertConstraint(UnitPropagationListener s) {
118 for (int i = 0; i < size(); i++) {
119 if (getVocabulary().isUnassigned(get(i))) {
120 boolean ret = s.enqueue(get(i), this);
121 assert ret;
122 }
123 }
124 }
125
126 public IVecInt computeAnImpliedClause() {
127 return null;
128 }
129
130 }