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.minisat.orders;
31
32 /**
33 * Utility class used to order the literals according to a specific heuristics.
34 *
35 */
36 final class ValuedLit implements Comparable<ValuedLit> {
37 final int id;
38
39 final int count;
40
41 ValuedLit(int id, int count) {
42 this.id = id;
43 this.count = count;
44 }
45
46 public int compareTo(ValuedLit t) {
47 if (this.count == 0) {
48 return Integer.MAX_VALUE;
49 }
50 if (t.count == 0) {
51 return -1;
52 }
53 return this.count - t.count;
54 }
55
56 @Override
57 public boolean equals(Object o) {
58 if (o == null) {
59 return false;
60 }
61 if (o instanceof ValuedLit) {
62 return ((ValuedLit) o).count == this.count;
63 }
64 return false;
65 }
66
67 @Override
68 public int hashCode() {
69 return this.id;
70 }
71
72 @Override
73 public String toString() {
74 return "" + this.id + "(" + this.count + ")"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
75 }
76 }