1 /*
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2006 Daniel Le Berre
3 *
4 * Based on the original minisat specification from:
5 *
6 * An extensible SAT solver. Niklas E?n and Niklas S?rensson. Proceedings of the
7 * Sixth International Conference on Theory and Applications of Satisfiability
8 * Testing, LNCS 2919, pp 502-518, 2003.
9 *
10 * This library is free software; you can redistribute it and/or modify it under
11 * the terms of the GNU Lesser General Public License as published by the Free
12 * Software Foundation; either version 2.1 of the License, or (at your option)
13 * any later version.
14 *
15 * This library is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with this library; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 */
25 package org.sat4j.opt;
26
27 import org.sat4j.specs.ISolver;
28 import org.sat4j.specs.TimeoutException;
29 import org.sat4j.tools.SolverDecorator;
30
31 public abstract class AbstractSelectorVariablesDecorator extends
32 SolverDecorator {
33
34 protected int nborigvars;
35
36 private int nbexpectedclauses;
37
38 protected int nbnewvar;
39
40 protected int[] prevfullmodel;
41
42 public AbstractSelectorVariablesDecorator(ISolver solver) {
43 super(solver);
44 }
45
46 @Override
47 public int[] model() {
48 int end = nborigvars - 1;
49 while (Math.abs(prevfullmodel[end]) > nborigvars)
50 end--;
51 int[] shortmodel = new int[end + 1];
52 for (int i = 0; i <= end; i++) {
53 shortmodel[i] = prevfullmodel[i];
54 }
55 return shortmodel;
56 }
57
58 @Override
59 public int newVar(int howmany) {
60 nborigvars = super.newVar(howmany);
61 return nborigvars;
62 }
63
64 @Override
65 public void setExpectedNumberOfClauses(int nb) {
66 nbexpectedclauses = nb;
67 super.setExpectedNumberOfClauses(nb);
68 super.newVar(nborigvars + nbexpectedclauses);
69 }
70
71 @Override
72 public void reset() {
73 super.reset();
74 nbnewvar = 0;
75 }
76
77 public boolean admitABetterSolution() throws TimeoutException {
78 boolean result = super.isSatisfiable();
79 if (result)
80 prevfullmodel = super.model();
81 return result;
82 }
83
84 }