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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  package org.sat4j.csp;
20  
21  import org.sat4j.core.VecInt;
22  import org.sat4j.specs.ContradictionException;
23  import org.sat4j.specs.ISolver;
24  import org.sat4j.specs.IVecInt;
25  
26  public class Var implements Evaluable {
27  
28      private final Domain domain;
29  
30      private final String id;
31  
32      private final int startid;
33  
34      public Var(String idvar, Domain domain, int lastvarnumber) {
35          this.domain = domain;
36          this.id = idvar;
37          this.startid = lastvarnumber + 1;
38      }
39  
40      /*
41       * (non-Javadoc)
42       * 
43       * @see org.sat4j.reader.csp.Evaluable#domain()
44       */
45      public Domain domain() {
46          return domain;
47      }
48  
49      /*
50       * (non-Javadoc)
51       * 
52       * @see org.sat4j.reader.csp.Evaluable#translate(int)
53       */
54      public int translate(int key) {
55          return domain.pos(key) + startid;
56      }
57  
58      /*
59       * (non-Javadoc)
60       * 
61       * @see org.sat4j.reader.csp.Evaluable#toClause(org.sat4j.specs.ISolver)
62       */
63      public void toClause(ISolver solver) throws ContradictionException {
64          IVecInt clause = new VecInt(domain.size());
65          for (int i = 0; i < domain.size(); i++)
66              clause.push(i + startid);
67          solver.addExactly(clause, 1);
68      }
69  
70      public int findValue(int[] model) {
71          for (int i = 0; i < domain.size(); i++) {
72              int varnum = i + startid;
73              if (model[varnum - 1] == varnum)
74                  return domain.get(i);
75          }
76          throw new IllegalStateException("BIG PROBLEM: no value for a var!");
77      }
78  
79      /*
80       * (non-Javadoc)
81       * 
82       * @see java.lang.Object#toString()
83       */
84      @Override
85      public String toString() {
86          return id;
87      }
88  
89  }