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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.minisat.constraints;
31  
32  import org.sat4j.minisat.constraints.cnf.Clauses;
33  import org.sat4j.minisat.constraints.cnf.LearntWLClause;
34  import org.sat4j.minisat.constraints.cnf.Lits;
35  import org.sat4j.minisat.constraints.cnf.OriginalBinaryClause;
36  import org.sat4j.minisat.constraints.cnf.OriginalWLClause;
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   * @author leberre To change the template for this generated type comment go to
45   *         Window - Preferences - Java - Code Generation - Code and Comments
46   */
47  public class ClausalDataStructureWL extends AbstractDataStructureFactory {
48  
49      private static final long serialVersionUID = 1L;
50  
51      /*
52       * (non-Javadoc)
53       * 
54       * @see
55       * org.sat4j.minisat.DataStructureFactory#createClause(org.sat4j.datatype
56       * .VecInt)
57       */
58      public Constr createClause(IVecInt literals) throws ContradictionException {
59          IVecInt v = Clauses.sanityCheck(literals, getVocabulary(), this.solver);
60          if (v == null) {
61              // tautological clause
62              return null;
63          }
64          if (v.size() == 1) {
65              return new UnitClause(v.last());
66          }
67          if (v.size() == 2) {
68              return OriginalBinaryClause.brandNewClause(this.solver,
69                      getVocabulary(), v);
70          }
71          return OriginalWLClause.brandNewClause(this.solver, getVocabulary(), v);
72      }
73  
74      public Constr createUnregisteredClause(IVecInt literals) {
75          return new LearntWLClause(literals, getVocabulary());
76      }
77  
78      @Override
79      protected ILits createLits() {
80          return new Lits();
81      }
82  }