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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;
29  
30  import java.math.BigInteger;
31  
32  import org.sat4j.core.Vec;
33  import org.sat4j.core.VecInt;
34  import org.sat4j.minisat.constraints.cnf.Clauses;
35  import org.sat4j.pb.constraints.pb.PBConstr;
36  import org.sat4j.pb.constraints.pb.Pseudos;
37  import org.sat4j.specs.ContradictionException;
38  import org.sat4j.specs.IVec;
39  import org.sat4j.specs.IVecInt;
40  
41  /**
42   *
43   * @author anne
44   */
45  public class CompetPBMaxClauseCardConstrDataStructure 
46          extends PBMaxClauseCardConstrDataStructure{ 
47  
48          /**
49  	 * 
50  	 */
51  	private static final long serialVersionUID = 1L;
52  
53  		/*
54       * (non-Javadoc)
55       * 
56       * @see org.sat4j.minisat.constraints.AbstractPBDataStructureFactory#constraintFactory(org.sat4j.specs.VecInt,
57       *      org.sat4j.specs.VecInt, boolean, int)
58       */
59      @Override
60      protected PBConstr constraintFactory(IVecInt literals,
61              IVec<BigInteger> coefs, boolean moreThan, BigInteger degree)
62              throws ContradictionException {
63          int[] theLits = new int[literals.size()];
64          literals.copyTo(theLits);
65          BigInteger[] normCoefs = new BigInteger[coefs.size()];
66          coefs.copyTo(normCoefs);
67  
68          BigInteger bigDegree = Pseudos.niceParametersForCompetition(theLits, normCoefs,
69                  moreThan, degree);
70          if (bigDegree == null)
71              return null;
72          if (bigDegree.equals(BigInteger.ONE)) {
73              IVecInt v = Clauses.sanityCheck(new VecInt(theLits), getVocabulary(),
74                      solver);
75              if (v == null)
76                  return null;
77              return constructClause(v);
78          }
79          if (coefficientsEqualToOne(new Vec<BigInteger>(normCoefs))) {
80              assert bigDegree.compareTo(MAX_INT_VALUE) < 0;
81              return constructCard(new VecInt(theLits), bigDegree.intValue());
82          }
83          //return constructPB(mpb);
84          return constructPB(theLits,normCoefs,bigDegree);
85      }
86  
87  }