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;
31
32 import java.io.FileNotFoundException;
33 import java.io.IOException;
34 import java.io.PrintWriter;
35
36 import org.sat4j.minisat.SolverFactory;
37 import org.sat4j.reader.InstanceReader;
38 import org.sat4j.reader.ParseFormatException;
39 import org.sat4j.reader.Reader;
40 import org.sat4j.specs.ContradictionException;
41 import org.sat4j.specs.IProblem;
42 import org.sat4j.specs.ISolver;
43 import org.sat4j.specs.IVecInt;
44 import org.sat4j.specs.TimeoutException;
45 import org.sat4j.tools.RemiUtils;
46 import org.sat4j.tools.SolutionCounter;
47
48 /**
49 * This is an example of use of the SAT4J library for computing the backbone of
50 * a CNF or to compute the number of solutions of a CNF. We do not claim that
51 * those tools are very efficient: they were simple to write and they helped us
52 * on small examples.
53 *
54 * @author leberre
55 */
56 public final class MoreThanSAT {
57
58 /**
59 * This constructor is private to prevent people to use instances of that
60 * class.
61 *
62 */
63 private MoreThanSAT() {
64 // to silent PMD audit
65 }
66
67 public static void main(final String[] args) {
68 final ISolver solver = SolverFactory.newDefault();
69 final SolutionCounter sc = new SolutionCounter(solver);
70 solver.setTimeout(3600); // 1 hour timeout
71 Reader reader = new InstanceReader(solver);
72
73 // filename is given on the command line
74 try {
75 final IProblem problem = reader.parseInstance(args[0]);
76 if (problem.isSatisfiable()) {
77 System.out.println(Messages.getString("MoreThanSAT.0")); //$NON-NLS-1$
78 reader.decode(problem.model(), new PrintWriter(System.out));
79 IVecInt backbone = RemiUtils.backbone(solver);
80 System.out
81 .println(Messages.getString("MoreThanSAT.1") + backbone); //$NON-NLS-1$
82 System.out.println(Messages.getString("MoreThanSAT.2")); //$NON-NLS-1$
83 System.out.println(Messages.getString("MoreThanSAT.3") //$NON-NLS-1$
84 + sc.countSolutions());
85 } else {
86 System.out.println(Messages.getString("MoreThanSAT.4")); //$NON-NLS-1$
87 }
88 } catch (FileNotFoundException e) {
89 e.printStackTrace();
90 } catch (ParseFormatException e) {
91 e.printStackTrace();
92 } catch (IOException e) {
93 e.printStackTrace();
94 } catch (ContradictionException e) {
95 System.out.println(Messages.getString("MoreThanSAT.5")); //$NON-NLS-1$
96 } catch (TimeoutException e) {
97 System.out.println(Messages.getString("MoreThanSAT.6")); //$NON-NLS-1$
98 }
99 }
100 }