/**
* Updates the lower bound of the domain of <code>this</code> to <code>value</code>. The
* instruction comes from <code>propagator</code>.
*
* <ul>
* <li>If <code>value</code> is smaller than the lower bound of the domain, nothing is done and
* the return value is <code>false</code>,
* <li>if updating the lower bound to <code>value</code> leads to a dead-end (domain wipe-out),
* a <code>ContradictionException</code> is thrown,
* <li>otherwise, if updating the lower bound to <code>value</code> can be done safely, the
* event type is created (the original event can be promoted) and observers are notified and
* the return value is <code>true</code>
* </ul>
*
* @param value new lower bound (included)
* @param cause updating releaser
* @param informCause
* @return true if the lower bound has been updated, false otherwise
* @throws solver.exception.ContradictionException if the domain become empty due to this action
*/
public boolean updateLowerBound(int value, ICause cause, boolean informCause)
throws ContradictionException {
boolean change;
ICause antipromo = cause;
if (informCause) {
cause = Cause.Null;
}
int old = this.getLB();
if (old < value) {
if (this.getUB() < value) {
solver.getExplainer().updateLowerBound(this, old, value, antipromo);
this.contradiction(cause, MSG_LOW);
} else {
EventType e = EventType.INCLOW;
int aValue = value - OFFSET;
if (reactOnRemoval) {
// BEWARE: this loop significantly decreases performances
for (int i = old - OFFSET; i < aValue; i = VALUES.nextSetBit(i + 1)) {
delta.add(i + OFFSET);
}
}
VALUES.clear(old - OFFSET, aValue);
LB.set(VALUES.nextSetBit(aValue));
int _size = SIZE.get();
int card = VALUES.cardinality();
SIZE.set(card);
change = _size - card > 0;
if (instantiated()) {
e = EventType.INSTANTIATE;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
assert (change);
this.notifyPropagators(e, cause);
solver.getExplainer().updateLowerBound(this, old, value, antipromo);
return change;
}
}
return false;
}
private void checkGamma(int idx) throws ContradictionException {
if (beta.get() < gamma.get()
&& idx < gamma.get()
&& !vars[idx].isInDomainEnveloppe(s)
&& vars[idx].isInDomainKernel(t)) {
gamma.set(idx);
if (beta.get() > idx) {
vars[alpha.get()].remFromEnveloppe(t, this, true);
vars[alpha.get()].addToKernel(s, this, true);
}
}
}
private void propagate(int idx) throws ContradictionException {
if (beta.get() <= gamma.get()) {
SetVar var = vars[idx];
if ((idx == alpha.get()) && checkKerEnv(var)) {
updateVar(var);
alpha.add(1);
while (alpha.get() < beta.get()) {
updateVar(vars[alpha.get()]);
alpha.add(1);
}
while (alpha.get() < n && checkKerEnv(vars[alpha.get()])) {
updateVar(vars[alpha.get()]);
alpha.add(1);
}
beta.set(alpha.get());
if (alpha.get() < n) updateBeta();
} else if (idx == beta.get() && checkKerEnv(var)) {
updateBeta();
}
checkGamma(idx);
}
}
/**
* Removes <code>value</code>from the domain of <code>this</code>. The instruction comes from
* <code>propagator</code>.
*
* <ul>
* <li>If <code>value</code> is out of the domain, nothing is done and the return value is
* <code>false</code>,
* <li>if removing <code>value</code> leads to a dead-end (domain wipe-out), a <code>
* ContradictionException</code> is thrown,
* <li>otherwise, if removing <code>value</code> from the domain can be done safely, the event
* type is created (the original event can be promoted) and observers are notified and the
* return value is <code>true</code>
* </ul>
*
* @param value value to remove from the domain (int)
* @param cause removal releaser
* @param informCause
* @return true if the value has been removed, false otherwise
* @throws solver.exception.ContradictionException if the domain become empty due to this action
*/
public boolean removeValue(int value, ICause cause, boolean informCause)
throws ContradictionException {
// BEWARE: THIS CODE SHOULD NOT BE MOVED TO THE DOMAIN TO NOT DECREASE PERFORMANCES!
boolean change = false;
ICause antipromo = cause;
if (informCause) {
cause = Cause.Null;
}
int inf = getLB();
int sup = getUB();
if (value == inf && value == sup) {
solver.getExplainer().removeValue(this, value, antipromo);
this.contradiction(cause, MSG_REMOVE);
} else {
if (inf <= value && value <= sup) {
EventType e = EventType.REMOVE;
int aValue = value - OFFSET;
change = VALUES.get(aValue);
this.VALUES.set(aValue, false);
if (change) {
this.SIZE.add(-1);
if (reactOnRemoval) {
delta.add(aValue + OFFSET);
}
}
if (value == inf) {
LB.set(VALUES.nextSetBit(aValue));
e = EventType.INCLOW;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
} else if (value == sup) {
UB.set(VALUES.prevSetBit(aValue));
e = EventType.DECUPP;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
if (change && !VALUES.isEmpty()) {
if (this.instantiated()) {
e = EventType.INSTANTIATE;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
this.notifyPropagators(e, cause);
} else {
if (VALUES.isEmpty()) {
solver.getExplainer().removeValue(this, value, antipromo);
this.contradiction(cause, MSG_EMPTY);
}
}
}
}
if (change) {
solver.getExplainer().removeValue(this, value, antipromo);
}
return change;
}
@Override
public void propagate(int evtmask) throws ContradictionException {
for (int i = 0; i < n; i++) {
sccFirst[i].set(-1);
sccNext[i].set(-1);
mates[i].clear();
G_R.getActiveNodes().desactivate(i);
}
ArrayList<TIntArrayList> allSCC = StrongConnectivityFinder.findAllSCCOf(G.getEnvelopGraph());
int s = allSCC.size();
n_R.set(s);
int elem;
TIntArrayList list;
for (int i = 0; i < s; i++) {
list = allSCC.get(i);
G_R.getActiveNodes().activate(i);
for (int j = list.size() - 1; j >= 0; j--) {
elem = list.get(j);
sccOf[elem].set(i);
addNode(i, elem);
}
}
INeighbors succs;
int x;
for (int i = 0; i < n; i++) {
x = sccOf[i].get();
succs = G.getEnvelopGraph().getSuccessorsOf(i);
for (int j = succs.getFirstElement(); j >= 0; j = succs.getNextElement()) {
if (x != sccOf[j].get()) {
G_R.addArc(x, sccOf[j].get());
mates[x].add((i + 1) * n + j);
}
}
}
int first = -1;
int last = -1;
for (int i = 0; i < s; i++) {
if (G_R.getPredecessorsOf(i).isEmpty()) {
first = i;
}
if (G_R.getSuccessorsOf(i).isEmpty()) {
last = i;
}
}
if (first == -1 || last == -1 || first == last) {
contradiction(G, "");
}
if (visit(first, last) != n_R.get()) {
contradiction(G, "");
}
int to, arc;
for (int i = 0; i < n; i++) {
to = G.getKernelGraph().getSuccessorsOf(i).getFirstElement();
x = sccOf[i].get();
if (to != -1 && sccOf[to].get() != x && mates[x].neighborhoodSize() > 1) {
arc = (i + 1) * n + to;
for (int a = mates[x].getFirstElement(); a >= 0; a = mates[x].getNextElement()) {
if (a != arc) {
G.removeArc(a / n - 1, a % n, this);
}
}
mates[x].clear();
mates[x].add(arc);
}
}
}
