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.tools;
26
27 import org.sat4j.core.VecInt;
28 import org.sat4j.specs.ContradictionException;
29 import org.sat4j.specs.ISolver;
30 import org.sat4j.specs.IVecInt;
31 import org.sat4j.specs.TimeoutException;
32
33 /**
34 * Another solver decorator that counts the number of solutions.
35 *
36 * Note that this approach is quite naive so do not expect it to work on large
37 * examples.
38 *
39 * @author leberre
40 *
41 */
42 public class SolutionCounter extends SolverDecorator {
43
44 /**
45 *
46 */
47 private static final long serialVersionUID = 1L;
48
49 public SolutionCounter(ISolver solver) {
50 super(solver);
51 }
52
53 public long countSolutions() throws TimeoutException {
54 long nbsols = 0;
55 boolean trivialfalsity = false;
56
57 while (!trivialfalsity && isSatisfiable()) {
58 nbsols++;
59 int[] last = model();
60 IVecInt clause = new VecInt(last.length);
61 for (int q : last) {
62 clause.push(-q);
63 }
64 try {
65 // System.out.println("Sol number "+nbsols+" adding " + clause);
66 addClause(clause);
67 } catch (ContradictionException e) {
68 trivialfalsity = true;
69 }
70 }
71 return nbsols;
72 }
73 }