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Open-source constraint solver.
/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2023, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver.constraints.extension.binary;
import org.chocosolver.solver.constraints.extension.Tuples;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.events.IntEventType;
import org.chocosolver.solver.variables.events.PropagatorEventType;
import org.chocosolver.util.iterators.DisposableValueIterator;
import org.chocosolver.util.objects.setDataStructures.iterable.IntIterableBitSet;
import java.util.Arrays;
/**
*
*
* @author Charles Prud'homme, Hadrien Cambazard
* @since 24/04/2014
*/
public class PropBinAC3rm extends PropBinCSP {
private int[] currentSupport0;
private int[] currentSupport1;
private int offset0;
private int offset1;
private int[] initS0; //initial number of supports of each value of x0
private int[] initS1; //initial number of supports of each value of x0
private int minS0; //value with minimum number of supports for v0
private int minS1; //value with minimum number of supports for v1
private int initDomSize0;
private int initDomSize1;
private final IntIterableBitSet vrms;
public PropBinAC3rm(IntVar x, IntVar y, Tuples tuples) {
this(x, y, new CouplesBitSetTable(tuples, x, y));
}
private PropBinAC3rm(IntVar x, IntVar y, CouplesBitSetTable table) {
super(x, y, table);
vrms = new IntIterableBitSet();
}
@Override
public void propagate(int evtmask) throws ContradictionException {
if (PropagatorEventType.isFullPropagation(evtmask)) {
initProp();
}
reviseV0();
reviseV1();
}
@Override
public void propagate(int idxVarInProp, int mask) throws ContradictionException {
if (IntEventType.isInstantiate(mask)) {
onInstantiationOf(idxVarInProp);
} else if (idxVarInProp == 0) {
reviseV1();
} else {
reviseV0();
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
private void fastInitNbSupports(int a, int b) {
DisposableValueIterator itv0 = v0.getValueIterator(true);
int cpt1 = 0;
while (itv0.hasNext()) {
int val0 = itv0.next();
cpt1++;
DisposableValueIterator itv1 = v1.getValueIterator(true);
int cpt2 = 0;
while (itv1.hasNext()) {
cpt2++;
int val1 = itv1.next();
if (relation.isConsistent(val0, val1)) {
initS0[val0 - offset0]++;
initS1[val1 - offset1]++;
}
if (cpt2 >= a) break;
}
itv1.dispose();
if (cpt1 >= b) break;
}
itv0.dispose();
minS0 = Integer.MAX_VALUE;
minS1 = Integer.MAX_VALUE;
for (int i = 0; i < initS0.length; i++) {
if (initS0[i] < minS0) minS0 = initS0[i];
}
for (int i = 0; i < initS1.length; i++) {
if (initS1[i] < minS1) minS1 = initS1[i];
}
}
private boolean testDeepakConditionV1(int y, int v0Size) {
return initS1[y - offset1] <= (initDomSize0 - v0Size);
}
private boolean testDeepakConditionV0(int x, int v1Size) {
return initS0[x - offset0] <= (initDomSize1 - v1Size);
}
private int getSupportV1(int y) {
return currentSupport1[y - offset1];
}
private int getSupportV0(int x) {
return currentSupport0[x - offset0];
}
/**
* updates the support for all values in the domain of v1, and remove unsupported values for v1
*
* @throws ContradictionException
*/
private void reviseV1() throws ContradictionException {
int v0Size = v0.getDomainSize();
if (minS1 <= (initDomSize0 - v0Size)) {
DisposableValueIterator itv1 = v1.getValueIterator(true);
vrms.clear();
vrms.setOffset(v1.getLB());
try {
while (itv1.hasNext()) {
int y = itv1.next();
if (testDeepakConditionV1(y, v0Size)) { //initS1[y - offset1] <= (initDomSize0 - v0Size)) {
if (!v0.contains(getSupportV1(y))) {
boolean found = false;
int support = 0;
DisposableValueIterator itv0 = v0.getValueIterator(true);
while (!found && itv0.hasNext()) {
support = itv0.next();
if (relation.isConsistent(support, y)) found = true;
}
itv0.dispose();
if (found) {
storeSupportV1(support, y);
} else {
vrms.add(y);
}
}
}
}
v1.removeValues(vrms, this);
} finally {
itv1.dispose();
}
}
}
/**
* updates the support for all values in the domain of v0, and remove unsupported values for v0
*
* @throws ContradictionException
*/
private void reviseV0() throws ContradictionException {
int v1Size = v1.getDomainSize();
if (minS0 <= (initDomSize1 - v1Size)) {
DisposableValueIterator itv0 = v0.getValueIterator(true);
vrms.clear();
vrms.setOffset(v0.getLB());
try {
while (itv0.hasNext()) {
int x = itv0.next();
if (testDeepakConditionV0(x, v1Size)) { //initS0[x - offset0] <= (initDomSize1 - v1Size)) {
if (!v1.contains(getSupportV0(x))) {
boolean found = false;
int support = 0;
DisposableValueIterator itv1 = v1.getValueIterator(true);
while (!found && itv1.hasNext()) {
support = itv1.next();
if (relation.isConsistent(x, support)) found = true;
}
itv1.dispose();
if (found) {
storeSupportV0(support, x);
} else {
vrms.add(x);
}
}
}
}
v0.removeValues(vrms, this);
} finally {
itv0.dispose();
}
}
}
private void storeSupportV0(int support, int x) {
currentSupport0[x - offset0] = support;
currentSupport1[support - offset1] = x;
}
private void storeSupportV1(int support, int y) {
currentSupport1[y - offset1] = support;
currentSupport0[support - offset0] = y;
}
private void initProp() throws ContradictionException {
offset1 = v1.getLB();
offset0 = v0.getLB();
currentSupport0 = new int[v0.getUB() - v0.getLB() + 1];
currentSupport1 = new int[v1.getUB() - v1.getLB() + 1];
initS0 = new int[v0.getUB() - v0.getLB() + 1];
initS1 = new int[v1.getUB() - v1.getLB() + 1];
initDomSize0 = v0.getDomainSize();
initDomSize1 = v1.getDomainSize();
Arrays.fill(currentSupport0, -1);
Arrays.fill(currentSupport1, -1);
//double cardprod = v0.getDomainSize() * v1.getDomainSize();
//if (cardprod <= 7000)
fastInitNbSupports(Integer.MAX_VALUE, Integer.MAX_VALUE);
//else fastInitNbSupports(80,80);
DisposableValueIterator itv0 = v0.getValueIterator(true);
vrms.clear();
vrms.setOffset(v0.getLB());
int support = 0;
boolean found = false;
try {
while (itv0.hasNext()) {
DisposableValueIterator itv1 = v1.getValueIterator(true);
int val0 = itv0.next();
while (itv1.hasNext()) {
int val1 = itv1.next();
if (relation.isConsistent(val0, val1)) {
support = val1;
found = true;
break;
}
}
itv1.dispose();
if (!found) {
vrms.add(val0);
} else {
storeSupportV0(support, val0);
}
found = false;
}
v0.removeValues(vrms, this);
} finally {
itv0.dispose();
}
found = false;
DisposableValueIterator itv1 = v1.getValueIterator(true);
vrms.clear();
vrms.setOffset(v1.getLB());
try {
while (itv1.hasNext()) {
itv0 = v0.getValueIterator(true);
int val1 = itv1.next();
while (itv0.hasNext()) {
int val0 = itv0.next();
if (relation.isConsistent(val0, val1)) {
support = val0;
found = true;
break;
}
}
itv0.dispose();
if (!found) {
vrms.add(val1);
} else {
storeSupportV1(support, val1);
}
found = false;
}
v1.removeValues(vrms, this);
} finally {
itv1.dispose();
}
//propagate();
}
private void onInstantiationOf(int idx) throws ContradictionException {
if (idx == 0) {
int value = v0.getValue();
DisposableValueIterator iterator = v1.getValueIterator(true);
vrms.clear();
vrms.setOffset(v1.getLB());
try {
while (iterator.hasNext()) {
int val = iterator.next();
if (!relation.isConsistent(value, val)) {
vrms.add(val);
}
}
v1.removeValues(vrms, this);
} finally {
iterator.dispose();
}
} else {
int value = v1.getValue();
DisposableValueIterator iterator = v0.getValueIterator(true);
vrms.clear();
vrms.setOffset(v0.getLB());
try {
while (iterator.hasNext()) {
int val = iterator.next();
if (!relation.isConsistent(val, value)) {
vrms.add(val);
}
}
v0.removeValues(vrms, this);
} finally {
iterator.dispose();
}
}
}
}