|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| IOrder | Line # 37 | 0 | 1 | - |
-1.0
|
||||||||||||||||||||||||||||||||||||||||||||||||||||
| No Tests | |||
| 1 | /* | |
| 2 | * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2006 Daniel Le Berre | |
| 3 | * | |
| 4 | * Based on the original minisat specification from: | |
| 5 | * | |
| 6 | * An extensible SAT solver. Niklas E?n and Niklas S?rensson. Proceedings of the | |
| 7 | * Sixth International Conference on Theory and Applications of Satisfiability | |
| 8 | * Testing, LNCS 2919, pp 502-518, 2003. | |
| 9 | * | |
| 10 | * This library is free software; you can redistribute it and/or modify it under | |
| 11 | * the terms of the GNU Lesser General Public License as published by the Free | |
| 12 | * Software Foundation; either version 2.1 of the License, or (at your option) | |
| 13 | * any later version. | |
| 14 | * | |
| 15 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
| 16 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
| 17 | * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more | |
| 18 | * details. | |
| 19 | * | |
| 20 | * You should have received a copy of the GNU Lesser General Public License | |
| 21 | * along with this library; if not, write to the Free Software Foundation, Inc., | |
| 22 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 23 | * | |
| 24 | */ | |
| 25 | package org.sat4j.minisat.core; | |
| 26 | ||
| 27 | import java.io.PrintWriter; | |
| 28 | ||
| 29 | /** | |
| 30 | * Interface for the variable ordering heuristics. It has both the | |
| 31 | * responsability to choose the next variable to branch on and the phase of the | |
| 32 | * literal (positive or negative one). | |
| 33 | * | |
| 34 | * @author daniel | |
| 35 | * | |
| 36 | */ | |
| 37 | public interface IOrder<L extends ILits> { | |
| 38 | ||
| 39 | /** | |
| 40 | * Method used to provide an easy access the the solver vocabulary. | |
| 41 | * | |
| 42 | * @param lits | |
| 43 | * the vocabulary | |
| 44 | */ | |
| 45 | void setLits(L lits); | |
| 46 | ||
| 47 | /** | |
| 48 | * Method called each time Solver.newVar() is called. | |
| 49 | * | |
| 50 | */ | |
| 51 | @Deprecated | |
| 52 | void newVar(); | |
| 53 | ||
| 54 | /** | |
| 55 | * Method called when Solver.newVar(int) is called. | |
| 56 | * | |
| 57 | * @param howmany | |
| 58 | * the maximum number of variables | |
| 59 | * @see Solver#newVar(int) | |
| 60 | */ | |
| 61 | void newVar(int howmany); | |
| 62 | ||
| 63 | /** | |
| 64 | * Selects the next "best" unassigned literal. | |
| 65 | * | |
| 66 | * Note that it means selecting the best variable and the phase to branch on | |
| 67 | * first. | |
| 68 | * | |
| 69 | * @return an unassigned literal or Lit.UNDEFINED no such literal exists. | |
| 70 | */ | |
| 71 | int select(); | |
| 72 | ||
| 73 | /** | |
| 74 | * Method called when a variable is unassigned. | |
| 75 | * | |
| 76 | * It is useful to add back a variable in the pool of variables to order. | |
| 77 | * | |
| 78 | * @param x | |
| 79 | * a variable. | |
| 80 | */ | |
| 81 | void undo(int x); | |
| 82 | ||
| 83 | /** | |
| 84 | * To be called when the activity of a literal changed. | |
| 85 | * | |
| 86 | * @param p | |
| 87 | * a literal. The associated variable will be updated. | |
| 88 | */ | |
| 89 | void updateVar(int p); | |
| 90 | ||
| 91 | /** | |
| 92 | * that method has the responsability to initialize all arrays in the | |
| 93 | * heuristics. PLEASE CALL super.init() IF YOU OVERRIDE THAT METHOD. | |
| 94 | */ | |
| 95 | void init(); | |
| 96 | ||
| 97 | /** | |
| 98 | * Display statistics regarding the heuristics. | |
| 99 | * | |
| 100 | * @param out | |
| 101 | * the writer to display the information in | |
| 102 | * @param prefix | |
| 103 | * to be used in front of each newline. | |
| 104 | */ | |
| 105 | void printStat(PrintWriter out, String prefix); | |
| 106 | ||
| 107 | /** | |
| 108 | * Sets the variable activity decay as a growing factor for the next | |
| 109 | * variable activity. | |
| 110 | * | |
| 111 | * @param d | |
| 112 | * a number bigger than 1 that will increase the activity of the | |
| 113 | * variables involved in future conflict. This is similar but | |
| 114 | * more efficient than decaying all the activities by a similar | |
| 115 | * factor. | |
| 116 | */ | |
| 117 | void setVarDecay(double d); | |
| 118 | ||
| 119 | /** | |
| 120 | * Decay the variables activities. | |
| 121 | * | |
| 122 | */ | |
| 123 | void varDecayActivity(); | |
| 124 | ||
| 125 | /** | |
| 126 | * To obtain the current activity of a variable. | |
| 127 | * | |
| 128 | * @param p | |
| 129 | * a literal | |
| 130 | * @return the activity of the variable associated to that literal. | |
| 131 | */ | |
| 132 | double varActivity(int p); | |
| 133 | ||
| 134 | /** | |
| 135 | * indicate that a literal has been satisfied. | |
| 136 | * | |
| 137 | * @param p | |
| 138 | */ | |
| 139 | void assignLiteral(int p); | |
| 140 | } | |
|
||||||||||
