unsigned int OBRing::GetRootAtom()
{
vector<int>::iterator i;
OBMol *mol = (OBMol*)GetParent();
//if (!IsAromatic())
// return 0;
if (Size() == 6)
for (i = _path.begin();i != _path.end();++i)
if (!(mol->GetAtom(*i))->IsCarbon())
return (*i);
if (Size() == 5)
for (i = _path.begin();i != _path.end();++i) {
OBAtom *atom = mol->GetAtom(*i);
if (atom->IsSulfur() && (atom->GetValence() == 2))
return (*i);
if (atom->IsOxygen() && (atom->GetValence() == 2))
return (*i);
if (atom->IsNitrogen() && (atom->BOSum() == atom->GetValence()))
return (*i);
}
return 0;
}
