org.sat4j.csp.constraints.AllDiff Maven / Gradle / Ivy
/*******************************************************************************
* 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
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*
* 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
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package org.sat4j.csp.constraints;
import org.sat4j.core.VecInt;
import org.sat4j.csp.Clausifiable;
import org.sat4j.csp.Evaluable;
import org.sat4j.csp.Var;
import org.sat4j.specs.ContradictionException;
import org.sat4j.specs.ISolver;
import org.sat4j.specs.IVec;
import org.sat4j.specs.IVecInt;
import org.sat4j.specs.IteratorInt;
public class AllDiff implements Clausifiable {
public void toClause(ISolver solver, IVec scope, IVec vars)
throws ContradictionException {
int n = scope.size();
IVecInt clause = new VecInt();
int vali,valj;
for (int i = 0; i < n; i++) {
Var vi = scope.get(i);
for (int j = i + 1; j < n; j++) {
// make all values differents
Var vj = scope.get(j);
for (IteratorInt iti = vi.domain().iterator(); iti.hasNext();) {
vali = iti.next();
for (IteratorInt itj = vj.domain().iterator(); itj.hasNext();) {
valj = itj.next();
// the two variables share a common value
if (vali == valj) {
clause.push(-vi.translate(vali));
clause.push(-vj.translate(valj));
solver.addClause(clause);
clause.clear();
}
}
}
}
}
}
}