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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 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  *******************************************************************************/
28  package org.sat4j.minisat.constraints;
29  
30  import org.sat4j.minisat.constraints.card.AtLeast;
31  import org.sat4j.minisat.constraints.cnf.Clauses;
32  import org.sat4j.minisat.constraints.cnf.LearntBinaryClause;
33  import org.sat4j.minisat.constraints.cnf.LearntHTClause;
34  import org.sat4j.minisat.constraints.cnf.Lits;
35  import org.sat4j.minisat.constraints.cnf.OriginalBinaryClause;
36  import org.sat4j.minisat.constraints.cnf.OriginalHTClause;
37  import org.sat4j.minisat.constraints.cnf.UnitClause;
38  import org.sat4j.minisat.core.Constr;
39  import org.sat4j.minisat.core.ILits;
40  import org.sat4j.specs.ContradictionException;
41  import org.sat4j.specs.IVecInt;
42  
43  /**
44   * Uses specific data strcuture for cardinality constraints.
45   *
46   * @author leberre
47   */
48  public class MixedDataStructureDaniel extends AbstractDataStructureFactory<ILits> {
49  
50      private static final long serialVersionUID = 1L;
51  
52      /*
53       * (non-Javadoc)
54       * 
55       * @see org.sat4j.minisat.DataStructureFactory#createCardinalityConstraint(org.sat4j.datatype.VecInt,
56       *      int)
57       */
58      @Override
59      public Constr createCardinalityConstraint(IVecInt literals, int degree)
60              throws ContradictionException {
61          return AtLeast.atLeastNew(solver, getVocabulary(), literals, degree);
62      }
63  
64      /*
65       * (non-Javadoc)
66       * 
67       * @see org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype.VecInt)
68       */
69      public Constr createClause(IVecInt literals) throws ContradictionException {
70          IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), solver);
71          if (v == null)
72              return null;
73      	if (v.size()==2) {
74      		return OriginalBinaryClause.brandNewClause(solver, getVocabulary(), v);
75      	}
76          return OriginalHTClause.brandNewClause(solver, getVocabulary(), v);
77      }
78  
79      public Constr createUnregisteredClause(IVecInt literals) {
80      	if (literals.size()==1) {
81      		return new UnitClause(literals.last());
82      	}
83      	if (literals.size()==2) {
84      		return new LearntBinaryClause(literals,getVocabulary());
85      	}
86          return new LearntHTClause(literals, getVocabulary());
87      }
88  
89      @Override
90      protected ILits createLits() {
91          return new Lits();
92      }
93  }