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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.pb.core;
31  
32  import org.sat4j.minisat.core.IOrder;
33  import org.sat4j.minisat.core.LearningStrategy;
34  import org.sat4j.pb.constraints.pb.ConflictMapSwitchToClause;
35  import org.sat4j.pb.constraints.pb.IConflict;
36  import org.sat4j.pb.constraints.pb.PBConstr;
37  
38  public class PBSolverCautious extends PBSolverCP {
39  
40      private static final long serialVersionUID = 1L;
41      public static final int BOUND = 10;
42  
43      public PBSolverCautious(LearningStrategy<PBDataStructureFactory> learner,
44              PBDataStructureFactory dsf, IOrder order) {
45          super(learner, dsf, order);
46          ConflictMapSwitchToClause.UPPERBOUND = BOUND;
47      }
48  
49      public PBSolverCautious(LearningStrategy<PBDataStructureFactory> learner,
50              PBDataStructureFactory dsf, IOrder order, int bound) {
51          super(learner, dsf, order);
52          ConflictMapSwitchToClause.UPPERBOUND = bound;
53      }
54  
55      @Override
56      IConflict chooseConflict(PBConstr myconfl, int level) {
57          return ConflictMapSwitchToClause.createConflict(myconfl, level);
58      }
59  
60      @Override
61      public String toString(String prefix) {
62          return super.toString(prefix)
63                  + "\n"
64                  + prefix
65                  + "When dealing with too large coefficients, simplify asserted PB constraints to clauses";
66      }
67  
68      @Override
69      protected void updateNumberOfReductions(IConflict confl) {
70          this.stats.numberOfReductions += ((ConflictMapSwitchToClause) confl)
71                  .getNumberOfReductions();
72      }
73  
74      @Override
75      protected void updateNumberOfReducedLearnedConstraints(IConflict confl) {
76          if (((ConflictMapSwitchToClause) confl).hasBeenReduced()) {
77              this.stats.numberOfLearnedConstraintsReduced++;
78          }
79      }
80  
81  }