/*******************************************************************************
* SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU Lesser General Public License Version 2.1 or later (the
* "LGPL"), in which case the provisions of the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of the LGPL, and not to allow others to use your version of
* this file under the terms of the EPL, indicate your decision by deleting
* the provisions above and replace them with the notice and other provisions
* required by the LGPL. If you do not delete the provisions above, a recipient
* may use your version of this file under the terms of the EPL or the LGPL.
*
* Based on the original MiniSat specification from:
*
* An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
* Sixth International Conference on Theory and Applications of Satisfiability
* Testing, LNCS 2919, pp 502-518, 2003.
*
* See www.minisat.se for the original solver in C++.
*
*******************************************************************************/
package org.sat4j.reader;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.Serializable;
import org.sat4j.core.VecInt;
import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.IProblem;
import org.sat4j.specs.ISolver;
import org.sat4j.specs.IVecInt;
/**
* Dimacs Reader written by Frederic Laihem. It is much faster than DimacsReader
* because it does not split the input file into strings but reads and interpret
* the input char by char. Hence, it is a bit more difficult to read and to
* modify than DimacsReader.
*
* This reader is used during the SAT Competitions.
*
* @author laihem
* @author leberre
*/
public class LecteurDimacs extends Reader implements Serializable {
private static final long serialVersionUID = 1L;
/* taille du buffer */
private final static int TAILLE_BUF = 16384;
private final ISolver s;
private transient BufferedInputStream in;
/* nombre de literaux dans le fichier */
private int nbVars = -1;
private int nbClauses = -1;
private static final char EOF = (char) -1;
/*
* nomFichier repr?sente le nom du fichier ? lire
*/
public LecteurDimacs(ISolver s) {
this.s = s;
}
@Override
public final IProblem parseInstance(final InputStream input)
throws ParseFormatException, ContradictionException, IOException {
this.in = new BufferedInputStream(input, LecteurDimacs.TAILLE_BUF);
s.reset();
passerCommentaire();
if (nbVars < 0)
throw new ParseFormatException(
"DIMACS error: wrong max number of variables");
s.newVar(nbVars);
s.setExpectedNumberOfClauses(nbClauses);
char car = passerEspaces();
if (nbClauses>0) {
if (car == EOF)
throw new ParseFormatException("DIMACS error: the clauses are missing");
ajouterClauses(car);
}
input.close();
return s;
}
@Override
public IProblem parseInstance(java.io.Reader input) throws IOException,
ContradictionException {
throw new UnsupportedOperationException();
}
/** on passe les commentaires et on lit le nombre de literaux */
private char passerCommentaire() throws IOException {
char car;
for (;;) {
car = passerEspaces();
if (car == 'p') {
car = lectureNombreLiteraux();
}
if (car != 'c' && car != 'p')
break; /* fin des commentaires */
car = nextLine(); /* on passe la ligne de commentaire */
if (car == EOF)
break;
}
return car;
}
/** lit le nombre repr?sentant le nombre de literaux */
private char lectureNombreLiteraux() throws IOException {
char car = nextChiffre(); /* on lit le prchain chiffre */
if (car != EOF) {
nbVars = car - '0';
for (;;) { /* on lit le chiffre repr?sentant le nombre de literaux */
car = (char) in.read();
if (car < '0' || car > '9')
break;
nbVars = 10 * nbVars + (car - '0');
}
car = nextChiffre();
nbClauses = car - '0';
for (;;) { /* on lit le chiffre repr?sentant le nombre de literaux */
car = (char) in.read();
if (car < '0' || car > '9')
break;
nbClauses = 10 * nbClauses + (car - '0');
}
if (car != '\n' && car != EOF)
nextLine(); /* on lit la fin de la ligne */
}
return car;
}
/** lit les clauses et les ajoute dans le vecteur donn? en param?tre
* @throws ParseFormatException */
private void ajouterClauses(char car) throws IOException,
ContradictionException, ParseFormatException {
final IVecInt lit = new VecInt();
int val = 0;
boolean neg = false;
for (;;) {
/* on lit le signe du literal */
if (car == '-') {
neg = true;
car = (char) in.read();
} else if (car == '+')
car = (char) in.read();
else /* on le 1er chiffre du literal */
if (car >= '0' && car <= '9') {
val = car - '0';
car = (char) in.read();
} else
throw new ParseFormatException("Unknown character "+car);
/* on lit la suite du literal */
while (car >= '0' && car <= '9') {
val = (val * 10) + car - '0';
car = (char) in.read();
}
if (val == 0) { // on a lu toute la clause
s.addClause(lit);
lit.clear();
} else {
/* on ajoute le literal au vecteur */
// s.newVar(val-1);
lit.push(neg ? -val : val);
neg = false;
val = 0; /* on reinitialise les variables */
}
if (car != EOF)
car = passerEspaces();
if (car == EOF) {
if (!lit.isEmpty()) {
s.addClause(lit);
}
break; /* on a lu tout le fichier */
}
}
}
/** passe tout les caract?res d'espacement (espace ou \n) */
private char passerEspaces() throws IOException {
char car;
while ((car = (char) in.read()) == ' ' || car == '\n')
;
return car;
}
/** passe tout les caract?res jusqu? rencontrer une fin de la ligne */
private char nextLine() throws IOException {
char car;
do {
car = (char) in.read();
} while ((car != '\n') && (car != EOF));
return car;
}
/** passe tout les caract?re jusqu'? rencontrer un chiffre */
private char nextChiffre() throws IOException {
char car;
do {
car = (char) in.read();
} while ((car < '0') || (car > '9') && (car != EOF));
return car;
}
@Override
public String decode(int[] model) {
StringBuffer stb = new StringBuffer();
for (int i = 0; i < model.length; i++) {
stb.append(model[i]);
stb.append(" ");
}
stb.append("0");
return stb.toString();
}
@Override
public void decode(int[] model, PrintWriter out) {
for (int i = 0; i < model.length; i++) {
out.print(model[i]);
out.print(" ");
}
out.print("0");
}
}