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.cnf.MixableCBClause;
33 import org.sat4j.minisat.core.ILits;
34 import org.sat4j.minisat.core.UnitPropagationListener;
35 import org.sat4j.specs.IVecInt;
36
37 public final class MixableCBClausePB extends MixableCBClause implements
38 PBConstr {
39
40 /**
41 *
42 */
43 private static final long serialVersionUID = 1L;
44
45 public MixableCBClausePB(IVecInt ps, ILits voc, boolean learnt) {
46 super(ps, voc, learnt);
47 }
48
49 public MixableCBClausePB(IVecInt ps, ILits voc) {
50 super(ps, voc);
51 }
52
53 public static MixableCBClausePB brandNewClause(UnitPropagationListener s,
54 ILits voc, IVecInt literals) {
55 MixableCBClausePB c = new MixableCBClausePB(literals, voc);
56 c.register();
57 return c;
58 }
59
60 /*
61 * (non-Javadoc)
62 *
63 * @see org.sat4j.minisat.constraints.pb.PBConstr#computeAnImpliedClause()
64 */
65 public IVecInt computeAnImpliedClause() {
66 return null;
67 }
68
69 /*
70 * (non-Javadoc)
71 *
72 * @see org.sat4j.minisat.constraints.pb.PBConstr#getCoef(int)
73 */
74 public BigInteger getCoef(int literal) {
75 return BigInteger.ONE;
76 }
77
78 /*
79 * (non-Javadoc)
80 *
81 * @see org.sat4j.minisat.constraints.pb.PBConstr#getCoefs()
82 */
83 public BigInteger[] getCoefs() {
84 BigInteger[] tmp = new BigInteger[size()];
85 for (int i = 0; i < tmp.length; i++)
86 tmp[i] = BigInteger.ONE;
87 return tmp;
88 }
89
90 /*
91 * (non-Javadoc)
92 *
93 * @see org.sat4j.minisat.constraints.pb.PBConstr#getDegree()
94 */
95 public BigInteger getDegree() {
96 return BigInteger.ONE;
97 }
98
99 /*
100 * (non-Javadoc)
101 *
102 * @see org.sat4j.minisat.constraints.pb.PBConstr#getLits()
103 */
104 public int[] getLits() {
105 int[] tmp = new int[size()];
106 System.arraycopy(lits, 0, tmp, 0, size());
107 return tmp;
108 }
109
110 /*
111 * (non-Javadoc)
112 *
113 * @see org.sat4j.minisat.constraints.pb.PBConstr#getVocabulary()
114 */
115 public ILits getVocabulary() {
116 return voc;
117 }
118
119 /*
120 * (non-Javadoc)
121 *
122 * @see
123 * org.sat4j.minisat.core.Constr#assertConstraint(org.sat4j.minisat.core
124 * .UnitPropagationListener)
125 */
126 @Override
127 public void assertConstraint(UnitPropagationListener s) {
128 for (int i = 0; i < size(); i++)
129 if (getVocabulary().isUnassigned(get(i))) {
130 boolean ret = s.enqueue(get(i), this);
131 assert ret;
132 break;
133 }
134 }
135
136 }