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
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13 * under the terms of the LGPL, and not to allow others to use your version of
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18 *******************************************************************************/
19 package org.sat4j.csp.constraints;
20
21 import org.sat4j.core.VecInt;
22 import org.sat4j.csp.Domain;
23 import org.sat4j.csp.Evaluable;
24 import org.sat4j.csp.Var;
25 import org.sat4j.specs.ContradictionException;
26 import org.sat4j.specs.ISolver;
27 import org.sat4j.specs.IVec;
28 import org.sat4j.specs.IVecInt;
29 import org.sat4j.specs.IteratorInt;
30
31 public class AllDiffCard extends AllDiff {
32
33 public void toClause(ISolver solver, IVec<Var> scope, IVec<Evaluable> vars)
34 throws ContradictionException {
35 int n = scope.size();
36 Domain domain = scope.get(0).domain();
37
38 for (int i=1 ; i<n;i++) {
39 if (scope.get(i).domain() != domain) {
40 super.toClause(solver, scope, vars);
41 return;
42 }
43 }
44 // all the domains are the same
45 IVecInt clause = new VecInt();
46 int value;
47 for (IteratorInt it = domain.iterator() ; it.hasNext(); ) {
48 value = it.next();
49 for (int i=0;i<n;i++) {
50 clause.push(scope.get(i).translate(value));
51 }
52 solver.addAtMost(clause, 1);
53 clause.clear();
54 }
55 }
56
57 @Override
58 public String toString() {
59 return "AllDiff encoding using cardinality constraints";
60 }
61 }