void DPGlobalConstraint::propagateAC(){
bool changed = true;
clear();
//Cost thisUb;
//thisUb = wcsp->getUb();
for(int i = 0; i < arity(); i++){
EnumeratedVariable * x = scope[i];
bool first = true;
for(EnumeratedVariable::iterator it = x->begin(); it != x->end(); ++it){
if(zero[i][x->toIndex(*it)]) continue;
Result r = minCost(i, *it, changed && first);
if(changed && first) changed = false;
first = false;
Cost cost = r.first;
/*if(cost >= thisUb || cost + wcsp->getLb() + scope[i]->getCost(*it) >= thisUb){
x->remove(*it);
changed = true;
}else */
if(cost > 0){
project(i, *it, cost);
changed = true;
} else if(cost < 0) {
/* Should not happen*/
printf("Warning: AC propagation get negative cost\n");
extend(i, *it, -cost);
changed = true;
}
if(x->canbe(*it)) record(r.second);
}
x->findSupport();
}
}
void DPGlobalConstraint::findSupport(int var, bool &changed){
EnumeratedVariable * x = scope[var];
bool first = true;
vector<Value> remove;
for(EnumeratedVariable::iterator it = x->begin(); it != x->end(); ++it){
Cost cost;
Result r = pair<Cost, Value*>(0, NULL);
if(zero[var][x->toIndex(*it)]){
cost = 0;
}else{
r = minCost(var, *it, changed && first);
if(changed && first) changed = false;
first = false;
cost = r.first;
}
//deltaCost[var][x->toIndex(*it)] += x->getCost(*it);
deltaCost[var][x->toIndex(*it)] += preUnaryCosts[var][x->toIndex(*it)];
//Cost delta = cost - x->getCost(*it);
Cost delta = cost - preUnaryCosts[var][x->toIndex(*it)];
if(delta > 0){
project(var, *it, delta, true); // NC will be delayed (avoid forward checking on binary/ternay cost functions)
assert(x->canbe(*it));
} else if (delta < 0) {
extend(var, *it, -delta);
}
if (!zero[var][x->toIndex(*it)] && x->getCost(*it) + wcsp->getLb() < wcsp->getUb()) record(r.second);
}
x->findSupport();
changed = true; //Detect any change in variable domain or unary costs
}
