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.core;
29
30 import java.math.BigInteger;
31
32 import org.sat4j.minisat.core.AssertingClauseGenerator;
33 import org.sat4j.minisat.core.ILits;
34 import org.sat4j.minisat.core.IOrder;
35 import org.sat4j.minisat.core.LearningStrategy;
36 import org.sat4j.pb.constraints.pb.PBConstr;
37 import org.sat4j.specs.ContradictionException;
38 import org.sat4j.specs.IConstr;
39 import org.sat4j.specs.IVec;
40 import org.sat4j.specs.IVecInt;
41
42 public class PBSolverWithImpliedClause extends PBSolverCP<ILits> {
43
44 public PBSolverWithImpliedClause(AssertingClauseGenerator acg,
45 LearningStrategy<ILits,PBDataStructureFactory<ILits>> learner, PBDataStructureFactory<ILits> dsf, IOrder<ILits> order) {
46 super(acg, learner, dsf, order);
47 }
48
49 /**
50 *
51 */
52 private static final long serialVersionUID = 1L;
53
54 @Override
55 public IConstr addPseudoBoolean(IVecInt literals, IVec<BigInteger> coeffs,
56 boolean moreThan, BigInteger degree) throws ContradictionException {
57 IVecInt vlits = dimacs2internal(literals);
58 assert vlits.size() == literals.size();
59 assert literals.size() == coeffs.size();
60 PBConstr result = (PBConstr)dsfactory.createPseudoBooleanConstraint(
61 vlits, coeffs, moreThan, degree);
62 if (result != null) {
63 IVecInt clits = result.computeAnImpliedClause();
64 if (clits != null) {
65 addConstr(dsfactory.createClause(clits));
66 }
67 }
68 return addConstr(result);
69 }
70
71 @Override
72 public String toString(String prefix) {
73 return super.toString(prefix) + "\n" + prefix
74 + "Add implied clauses in preprocessing";
75 }
76 }