/*
* Copyright (c) 1999-2014, Ecole des Mines de Nantes
* All rights reserved.
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* modification, are permitted provided that the following conditions are met:
*
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* documentation and/or other materials provided with the distribution.
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* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
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package solver.constraints.ternary;
import solver.Solver;
import solver.constraints.Constraint;
import solver.constraints.IntConstraintFactory;
import solver.variables.IntVar;
import solver.variables.impl.IntervalIntVarImpl;
import util.tools.StringUtils;
/**
* X = MAX(Y,Z)
* <br/>
*
* @author Charles Prud'homme
* @since 19/04/11
*/
public class Max extends Constraint {
public Max(IntVar X, IntVar Y, IntVar Z) {
super("Max",new PropMaxBC(X, Y, Z));
}
public static IntVar var(IntVar a, IntVar b) {
if (a.getLB() >= b.getUB()) {
return a;
} else if (b.getLB() >= a.getUB()) {
return b;
} else {
Solver solver = a.getSolver();
IntVar z = new IntervalIntVarImpl(StringUtils.randomName(),
Math.max(a.getLB(), b.getLB()), Math.max(a.getUB(), b.getUB()), solver);
solver.post(IntConstraintFactory.maximum(z, a, b));
return z;
}
}
}