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