bool connectionValid(int mask, Stat S){
for (int i = 0; i < 5; i++) if (maskGet(mask, i)){
Stat::iterator it = SSfind(S, i);
if (it != S.end()) S.erase(it);
}
return S.empty();
}
void SScombine(Stat &S, int i, int j){
Stat::iterator iti = SSfind(S, i);
Stat::iterator itj = SSfind(S, j);
if (iti == itj) return;
set<int> s(*iti);
for (set<int>::iterator it = itj->begin(); it != itj->end(); it++){
s.insert(*it);
}
S.erase(iti);
S.erase(itj);
S.insert(s);
}
void SSinsert(Stat &S, int i, int j){
Stat::iterator it = SSfind(S, j);
assert(it != S.end());
set<int> s(*it); S.erase(it);
s.insert(i); S.insert(s);
}