/**
* 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:
*
* * 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
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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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;
import util.tools.ArrayUtils;
import java.util.Arrays;
/**
* Inverse set propagator
* x in sets[y-offSet1] <=> y in inverses[x-offSet2]
*
* @author Jean-Guillaume Fages
*/
public class PropInverse extends Propagator<SetVar> {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
private int n, n2, idx;
private SetVar[] sets, invsets, toFilter;
private int offSet1, offSet2, offSet;
private ISetDeltaMonitor[] sdm;
private IntProcedure elementForced, elementRemoved;
//***********************************************************************************
// CONSTRUCTORS
//***********************************************************************************
/**
* Inverse set propagator
* x in sets[y-offSet1] <=> y in inverses[x-offSet2]
*/
public PropInverse(SetVar[] sets, SetVar[] invsets, int offSet1, int offSet2) {
super(ArrayUtils.append(sets, invsets), PropagatorPriority.LINEAR, true);
n = sets.length;
n2 = invsets.length;
this.offSet1 = offSet1;
this.offSet2 = offSet2;
this.sets = Arrays.copyOfRange(vars, 0, sets.length);
this.invsets = Arrays.copyOfRange(vars, sets.length, vars.length);
// delta monitors
sdm = new ISetDeltaMonitor[n + n2];
for (int i = 0; i < n + n2; i++) {
sdm[i] = this.vars[i].monitorDelta(this);
}
elementForced = new IntProcedure() {
@Override
public void execute(int element) throws ContradictionException {
toFilter[element - offSet].addToKernel(idx, aCause);
}
};
elementRemoved = new IntProcedure() {
@Override
public void execute(int element) throws ContradictionException {
toFilter[element - offSet].removeFromEnvelope(idx, aCause);
}
};
}
//***********************************************************************************
// METHODS
//***********************************************************************************
@Override
public void propagate(int evtmask) throws ContradictionException {
for (int i = 0; i < n; i++) {
for (int j=sets[i].getEnvelopeFirst(); j!=SetVar.END; j=sets[i].getEnvelopeNext()) {
if (j < offSet1 || j >= n2 + offSet1 || !invsets[j - offSet2].envelopeContains(i + offSet1)) {
sets[i].removeFromEnvelope(j, aCause);
}
}
for (int j=sets[i].getKernelFirst(); j!=SetVar.END; j=sets[i].getKernelNext()) {
invsets[j - offSet2].addToKernel(i + offSet1, aCause);
}
}
for (int i = 0; i < n2; i++) {
for (int j=invsets[i].getEnvelopeFirst(); j!=SetVar.END; j=invsets[i].getEnvelopeNext()) {
if (j < offSet2 || j >= n + offSet2 || !sets[j - offSet1].envelopeContains(i + offSet2)) {
invsets[i].removeFromEnvelope(j, aCause);
}
}
for (int j=invsets[i].getKernelFirst(); j!=SetVar.END; j=invsets[i].getKernelNext()) {
sets[j - offSet1].addToKernel(i + offSet2, aCause);
}
}
for (int i = 0; i < n + n2; i++) {
sdm[i].unfreeze();
}
}
@Override
public void propagate(int idxVarInProp, int mask) throws ContradictionException {
idx = idxVarInProp;
toFilter = invsets;
if (idx >= n) {
idx -= n;
toFilter = sets;
idx += offSet2;
offSet = offSet1;
} else {
idx += offSet1;
offSet = offSet2;
}
sdm[idxVarInProp].freeze();
sdm[idxVarInProp].forEach(elementForced, SetEventType.ADD_TO_KER);
sdm[idxVarInProp].forEach(elementRemoved, SetEventType.REMOVE_FROM_ENVELOPE);
sdm[idxVarInProp].unfreeze();
}
@Override
public ESat isEntailed() {
for (int i = 0; i < n; i++) {
for (int j=sets[i].getKernelFirst(); j!=SetVar.END; j=sets[i].getKernelNext()) {
if (!invsets[j - offSet2].envelopeContains(i + offSet1)) {
return ESat.FALSE;
}
}
}
for (int i = 0; i < n2; i++) {
for (int j=invsets[i].getKernelFirst(); j!=SetVar.END; j=invsets[i].getKernelNext()) {
if (!sets[j - offSet1].envelopeContains(i + offSet2)) {
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 s1 = sets.length;
SetVar[] set1 = new SetVar[s1];
for (int i = 0; i < s1; i++) {
sets[i].duplicate(solver, identitymap);
set1[i] = (SetVar) identitymap.get(sets[i]);
}
int s2 = invsets.length;
SetVar[] set2 = new SetVar[s2];
for (int i = 0; i < s2; i++) {
invsets[i].duplicate(solver, identitymap);
set2[i] = (SetVar) identitymap.get(invsets[i]);
}
identitymap.put(this, new PropInverse(set1, set2, offSet1, offSet2));
}
}
}