/**
* 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
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*/
/**
* Created by IntelliJ IDEA.
* User: Jean-Guillaume Fages
* Date: 14/01/13
* Time: 16:36
*/
package solver.constraints.set;
import gnu.trove.map.hash.THashMap;
import solver.Solver;
import solver.constraints.Propagator;
import solver.constraints.PropagatorPriority;
import solver.exception.ContradictionException;
import solver.variables.SetVar;
import solver.variables.delta.ISetDeltaMonitor;
import solver.variables.events.SetEventType;
import util.ESat;
import util.procedure.IntProcedure;
/**
* Propagator for symmetric sets
* x in set[y-offSet] <=> y in set[x-offSet]
*
* @author Jean-Guillaume Fages
*/
public class PropSymmetric extends Propagator<SetVar> {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
private int n, currentSet, offSet;
private ISetDeltaMonitor[] sdm;
private IntProcedure elementForced, elementRemoved;
//***********************************************************************************
// CONSTRUCTORS
//***********************************************************************************
/**
* Propagator for symmetric sets
* x in set[y-offSet] <=> y in set[x-offSet]
*/
public PropSymmetric(SetVar[] sets, final int offSet) {
super(sets, PropagatorPriority.LINEAR, true);
n = sets.length;
this.offSet = offSet;
sdm = new ISetDeltaMonitor[n];
for (int i = 0; i < n; i++) {
sdm[i] = this.vars[i].monitorDelta(this);
}
elementForced = new IntProcedure() {
@Override
public void execute(int element) throws ContradictionException {
vars[element - offSet].addToKernel(currentSet + offSet, aCause);
}
};
elementRemoved = new IntProcedure() {
@Override
public void execute(int element) throws ContradictionException {
vars[element - offSet].removeFromEnvelope(currentSet + offSet, aCause);
}
};
}
//***********************************************************************************
// METHODS
//***********************************************************************************
@Override
public void propagate(int evtmask) throws ContradictionException {
for (int i = 0; i < n; i++) {
for (int j = vars[i].getEnvelopeFirst(); j != SetVar.END; j = vars[i].getEnvelopeNext()) {
if (j < offSet || j >= n + offSet || !vars[j - offSet].envelopeContains(i + offSet)) {
vars[i].removeFromEnvelope(j, aCause);
}
}
for (int j = vars[i].getKernelFirst(); j != SetVar.END; j = vars[i].getKernelNext()) {
vars[j - offSet].addToKernel(i + offSet, aCause);
}
}
for (int i = 0; i < n; i++) {
sdm[i].unfreeze();
}
}
@Override
public void propagate(int idxVarInProp, int mask) throws ContradictionException {
currentSet = idxVarInProp;
sdm[currentSet].freeze();
sdm[currentSet].forEach(elementForced, SetEventType.ADD_TO_KER);
sdm[currentSet].forEach(elementRemoved, SetEventType.REMOVE_FROM_ENVELOPE);
sdm[currentSet].unfreeze();
}
@Override
public ESat isEntailed() {
for (int i = 0; i < n; i++) {
for (int j = vars[i].getKernelFirst(); j != SetVar.END; j = vars[i].getKernelNext()) {
if (!vars[j - offSet].envelopeContains(i + offSet)) {
return ESat.FALSE;
}
}
}
if (isCompletelyInstantiated()) {
return ESat.TRUE;
}
return ESat.UNDEFINED;
}
@Override
public void duplicate(Solver solver, THashMap<Object, Object> identitymap) {
if (!identitymap.containsKey(this)) {
int n = vars.length;
SetVar[] svars = new SetVar[n];
for (int i = 0; i < n; i++) {
vars[i].duplicate(solver, identitymap);
svars[i] = (SetVar) identitymap.get(vars[i]);
}
identitymap.put(this, new PropSymmetric(svars, offSet));
}
}
}