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.pb.constraints.pb;
31
32 import java.math.BigInteger;
33
34 import org.sat4j.minisat.constraints.card.AtLeast;
35 import org.sat4j.minisat.core.ILits;
36 import org.sat4j.specs.ContradictionException;
37 import org.sat4j.specs.IVecInt;
38 import org.sat4j.specs.UnitPropagationListener;
39
40 public final class AtLeastPB extends AtLeast implements PBConstr {
41
42 /**
43 *
44 */
45 private static final long serialVersionUID = 1L;
46
47 private final BigInteger degree;
48
49 private AtLeastPB(ILits voc, IVecInt ps, int degree) {
50 super(voc, ps, degree);
51 this.degree = BigInteger.valueOf(degree);
52 }
53
54 public static PBConstr atLeastNew(UnitPropagationListener s, ILits voc,
55 IVecInt ps, int n) throws ContradictionException {
56 int degree = niceParameters(s, voc, ps, n);
57 if (degree == 0) {
58 return new UnitClausesPB(ps);
59 }
60 return atLeastNew(voc, ps, degree);
61 }
62
63 public static AtLeastPB atLeastNew(ILits voc, IVecInt ps, int n) {
64 AtLeastPB atleast = new AtLeastPB(voc, ps, n);
65 atleast.register();
66 return atleast;
67 }
68
69 public BigInteger getCoef(int literal) {
70 return BigInteger.ONE;
71 }
72
73 public BigInteger getDegree() {
74 return this.degree;
75 }
76
77 public ILits getVocabulary() {
78 return this.voc;
79 }
80
81 public int[] getLits() {
82 int[] tmp = new int[size()];
83 System.arraycopy(this.lits, 0, tmp, 0, size());
84 return tmp;
85 }
86
87 public BigInteger[] getCoefs() {
88 BigInteger[] tmp = new BigInteger[size()];
89 for (int i = 0; i < tmp.length; i++) {
90 tmp[i] = BigInteger.ONE;
91 }
92 return tmp;
93 }
94
95 /**
96 *
97 */
98 private boolean learnt = false;
99
100 /**
101 * D?termine si la contrainte est apprise
102 *
103 * @return true si la contrainte est apprise, false sinon
104 * @see org.sat4j.specs.IConstr#learnt()
105 */
106 @Override
107 public boolean learnt() {
108 return this.learnt;
109 }
110
111 @Override
112 public void setLearnt() {
113 this.learnt = true;
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 }