1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
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 *******************************************************************************/
28 package org.sat4j;
29
30 import java.io.FileNotFoundException;
31 import java.io.IOException;
32 import java.io.PrintWriter;
33
34 import org.sat4j.minisat.SolverFactory;
35 import org.sat4j.reader.InstanceReader;
36 import org.sat4j.reader.ParseFormatException;
37 import org.sat4j.reader.Reader;
38 import org.sat4j.specs.ContradictionException;
39 import org.sat4j.specs.IProblem;
40 import org.sat4j.specs.ISolver;
41 import org.sat4j.specs.IVecInt;
42 import org.sat4j.specs.TimeoutException;
43 import org.sat4j.tools.RemiUtils;
44 import org.sat4j.tools.SolutionCounter;
45
46 /**
47 * This is an example of use of the SAT4J library for computing the backbone of
48 * a CNF or to compute the number of solutions of a CNF. We do not claim that
49 * those tools are very efficient: they were simple to write and they helped us
50 * on small examples.
51 *
52 * @author leberre
53 */
54 public final class MoreThanSAT {
55
56 /**
57 * This constructor is private to prevent people to use instances of that
58 * class.
59 *
60 */
61 private MoreThanSAT() {
62 // to silent PMD audit
63 }
64
65 public static void main(final String[] args) {
66 final ISolver solver = SolverFactory.newDefault();
67 final SolutionCounter sc = new SolutionCounter(solver);
68 solver.setTimeout(3600); // 1 hour timeout
69 Reader reader = new InstanceReader(solver);
70
71 // filename is given on the command line
72 try {
73 final IProblem problem = reader.parseInstance(args[0]);
74 if (problem.isSatisfiable()) {
75 System.out.println(Messages.getString("MoreThanSAT.0")); //$NON-NLS-1$
76 reader.decode(problem.model(), new PrintWriter(System.out));
77 IVecInt backbone = RemiUtils.backbone(solver);
78 System.out
79 .println(Messages.getString("MoreThanSAT.1") + backbone); //$NON-NLS-1$
80 System.out.println(Messages.getString("MoreThanSAT.2")); //$NON-NLS-1$
81 System.out.println(Messages.getString("MoreThanSAT.3") //$NON-NLS-1$
82 + sc.countSolutions());
83 } else {
84 System.out.println(Messages.getString("MoreThanSAT.4")); //$NON-NLS-1$
85 }
86 } catch (FileNotFoundException e) {
87 e.printStackTrace();
88 } catch (ParseFormatException e) {
89 e.printStackTrace();
90 } catch (IOException e) {
91 e.printStackTrace();
92 } catch (ContradictionException e) {
93 System.out.println(Messages.getString("MoreThanSAT.5")); //$NON-NLS-1$
94 } catch (TimeoutException e) {
95 System.out.println(Messages.getString("MoreThanSAT.6")); //$NON-NLS-1$
96 }
97 }
98 }