/**
* Main filtering algorithm: TODO 2) Implement filtering procedure of PropKCC (see isEntail)
*
* @param evtmask (useless for the exam)
* @throws ContradictionException (when a fail occurs)
*/
public void propagate(int evtmask) throws ContradictionException {
for (int i = 0; i < n; i++) {
g.getNeighborsOf(i).clear();
}
for (int i = 0; i < n; i++) {
for (int j = succs[i].getLB(); j <= succs[i].getUB(); j = succs[i].nextValue(j)) {
g.addEdge(i, j);
}
}
ccf.findAllCC();
nb.updateLowerBound(ccf.getNBCC(), aCause);
for (int i = 0; i < n; i++) {
g.getNeighborsOf(i).clear();
}
for (int i = 0; i < n; i++) {
if (succs[i].instantiated()) {
g.addEdge(i, succs[i].getValue());
}
}
ccf.findAllCC();
nb.updateUpperBound(ccf.getNBCC(), aCause);
}
/**
* Entailment checker
*
* @return ESat.FALSE if the propagator is violated ESat.TRUE if the propagator is satisfied for
* sure, no matter what happens next ESat.UNDEFINED otherwise
*/
public ESat isEntailed() {
// estimates the minimum number of cc of the solution by
// computing cc of the graph induced by variable domains
for (int i = 0; i < n; i++) {
g.getNeighborsOf(i).clear();
}
for (int i = 0; i < n; i++) {
for (int j = succs[i].getLB(); j <= succs[i].getUB(); j = succs[i].nextValue(j)) {
g.addEdge(i, j);
}
}
ccf.findAllCC();
if (nb.getUB() < ccf.getNBCC()) {
// too many CC
return ESat.FALSE;
}
// estimates the maximum number of cc of the solution by
// computing cc of the graph induced by instantiated variable values
for (int i = 0; i < n; i++) {
g.getNeighborsOf(i).clear();
}
for (int i = 0; i < n; i++) {
if (succs[i].instantiated()) {
g.addEdge(i, succs[i].getValue());
}
}
ccf.findAllCC();
if (nb.getLB() > ccf.getNBCC()) {
// not enough CC
return ESat.FALSE;
}
// if all variables are instantiated then this propagator is entailed
if (isCompletelyInstantiated()) {
return ESat.TRUE;
} else {
return ESat.UNDEFINED;
}
}