/**
* Copyright (c) 1999-2014, Ecole des Mines de Nantes
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Ecole des Mines de Nantes nor the
* 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
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package solver.constraints.extension.binary;
import gnu.trove.map.hash.THashMap;
import solver.Solver;
import solver.constraints.extension.Tuples;
import solver.exception.ContradictionException;
import solver.variables.IntVar;
import util.iterators.DisposableValueIterator;
/**
* <br/>
*
* @author Charles Prud'homme
* @since 24/04/2014
*/
public class PropBinAC3 extends PropBinCSP {
public PropBinAC3(IntVar x, IntVar y, Tuples tuples) {
this(x, y, new CouplesBitSetTable(tuples, x, y));
}
private PropBinAC3(IntVar x, IntVar y, CouplesBitSetTable table) {
super(x, y, table);
}
@Override
public void propagate(int evtmask) throws ContradictionException {
reviseV0();
reviseV1();
}
@Override
public void propagate(int idxVarInProp, int mask) throws ContradictionException {
if (idxVarInProp == 0) {
reviseV1();
} else
reviseV0();
}
@Override
public void duplicate(Solver solver, THashMap<Object, Object> identitymap) {
if (!identitymap.containsKey(this)) {
this.vars[0].duplicate(solver, identitymap);
IntVar X = (IntVar) identitymap.get(this.vars[0]);
this.vars[1].duplicate(solver, identitymap);
IntVar Y = (IntVar) identitymap.get(this.vars[1]);
identitymap.put(this, new PropBinAC3(X, Y, (CouplesBitSetTable) relation.duplicate()));
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* updates the support for all values in the domain of v1, and remove unsupported values for v1
*/
private void reviseV1() throws ContradictionException {
int nbs = 0;
int left = Integer.MIN_VALUE;
int right = left;
DisposableValueIterator itv1 = v1.getValueIterator(true);
while (itv1.hasNext()) {
int val1 = itv1.next();
DisposableValueIterator itv0 = v0.getValueIterator(true);
while (itv0.hasNext()) {
int val0 = itv0.next();
if (relation.isConsistent(val0, val1)) {
nbs += 1;
break;
}
}
itv0.dispose();
if (nbs == 0) {
if (val1 == right + 1) {
right = val1;
} else {
v1.removeInterval(left, right, this);
left = right = val1;
}
}
nbs = 0;
}
v1.removeInterval(left, right, this);
itv1.dispose();
}
/**
* updates the support for all values in the domain of v0, and remove unsupported values for v0
*/
private void reviseV0() throws ContradictionException {
int nbs = 0;
int left = Integer.MIN_VALUE;
int right = left;
DisposableValueIterator itv0 = v0.getValueIterator(true);
while (itv0.hasNext()) {
int val0 = itv0.next();
DisposableValueIterator itv1 = v1.getValueIterator(true);
while (itv1.hasNext()) {
int val1 = itv1.next();
if (relation.isConsistent(val0, val1)) {
nbs += 1;
break;
}
}
itv1.dispose();
if (nbs == 0) {
if (val0 == right + 1) {
right = val0;
} else {
v0.removeInterval(left, right, this);
left = right = val0;
}
}
nbs = 0;
}
v0.removeInterval(left, right, this);
itv0.dispose();
}
}