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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.tools;
31  
32  import java.math.BigInteger;
33  
34  import org.sat4j.ILauncherMode;
35  import org.sat4j.pb.IPBSolverService;
36  import org.sat4j.pb.ObjectiveFunction;
37  import org.sat4j.specs.RandomAccessModel;
38  import org.sat4j.specs.Lbool;
39  import org.sat4j.tools.SearchListenerAdapter;
40  import org.sat4j.tools.SolutionFoundListener;
41  
42  public final class SearchOptimizerListener extends
43          SearchListenerAdapter<IPBSolverService> {
44  
45      /**
46  	 * 
47  	 */
48      private static final long serialVersionUID = 1L;
49  
50      private IPBSolverService solverService;
51  
52      private ObjectiveFunction obj;
53  
54      private final SolutionFoundListener sfl;
55  
56      private BigInteger currentValue;
57  
58      public SearchOptimizerListener(SolutionFoundListener sfl) {
59          this.sfl = sfl;
60      }
61  
62      @Override
63      public void init(IPBSolverService solverService) {
64          this.obj = solverService.getObjectiveFunction();
65          this.solverService = solverService;
66          this.currentValue = null;
67      }
68  
69      @Override
70      public void solutionFound(int[] model, RandomAccessModel lazyModel) {
71          if (obj != null) {
72              this.currentValue = obj.calculateDegree(lazyModel);
73              System.out.println(ILauncherMode.CURRENT_OPTIMUM_VALUE_PREFIX
74                      + this.currentValue);
75              this.solverService
76                      .addAtMostOnTheFly(obj.getVars(), obj.getCoeffs(),
77                              this.currentValue.subtract(BigInteger.ONE));
78          }
79          sfl.onSolutionFound(model);
80      }
81  
82      @Override
83      public void end(Lbool result) {
84          if (result == Lbool.FALSE) {
85              sfl.onUnsatTermination();
86              System.out.println(solverService.getLogPrefix()
87                      + "objective function=" + currentValue);
88          }
89      }
90  
91      @Override
92      public String toString() {
93          return "Internal optimizer search listener";
94      }
95  }