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.minisat.orders;
29
30
31 /**
32 * Utility class used to order the literals according to a specific heuristics.
33 *
34 */
35 class ValuedLit implements Comparable<ValuedLit> {
36 final int id;
37
38 final int count;
39
40 ValuedLit(int id,int count) {
41 this.id = id;
42 this.count = count;
43 }
44
45 public int compareTo(ValuedLit t) {
46 if (count == 0) {
47 return Integer.MAX_VALUE;
48 }
49 if (t.count == 0) {
50 return -1;
51 }
52 return count - t.count;
53 }
54
55 @Override
56 public boolean equals(Object o) {
57 if (o == null)
58 return false;
59 if (o instanceof ValuedLit) {
60 return ((ValuedLit) o).count == count;
61 }
62 return false;
63 }
64
65 @Override
66 public int hashCode() {
67 return id;
68 }
69
70 @Override
71 public String toString() {
72 return "" + id + "(" + count + ")"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
73 }
74 }