bool MergeBestQ() {
const TFltIntIntTr TopQ = FindMxQEdge();
if (TopQ.Val1 <= 0.0) { return false; }
// joint communities
const int I = TopQ.Val3;
const int J = TopQ.Val2;
CmtyIdUF.Union(I, J); // join
Q += TopQ.Val1;
TCmtyDat& DatJ = CmtyQH.GetDat(J);
{ TCmtyDat& DatI = CmtyQH.GetDat(I);
DatI.DelLink(J); DatJ.DelLink(I);
for (int i = -1; DatJ.NIdQH.FNextKeyId(i); ) {
const int K = DatJ.NIdQH.GetKey(i);
TCmtyDat& DatK = CmtyQH.GetDat(K);
double NewQ = DatJ.NIdQH[i];
if (DatI.NIdQH.IsKey(K)) { NewQ = NewQ+DatI.NIdQH.GetDat(K); DatK.DelLink(I); } // K connected to I and J
else { NewQ = NewQ-2*DatI.DegFrac*DatK.DegFrac; } // K connected to J not I
DatJ.AddQ(K, NewQ);
DatK.AddQ(J, NewQ);
MxQHeap.PushHeap(TFltIntIntTr(NewQ, TMath::Mn(J,K), TMath::Mx(J,K)));
}
for (int i = -1; DatI.NIdQH.FNextKeyId(i); ) {
const int K = DatI.NIdQH.GetKey(i);
if (! DatJ.NIdQH.IsKey(K)) { // K connected to I not J
TCmtyDat& DatK = CmtyQH.GetDat(K);
const double NewQ = DatI.NIdQH[i]-2*DatJ.DegFrac*DatK.DegFrac;
DatJ.AddQ(K, NewQ);
DatK.DelLink(I);
DatK.AddQ(J, NewQ);
MxQHeap.PushHeap(TFltIntIntTr(NewQ, TMath::Mn(J,K), TMath::Mx(J,K)));
}
}
DatJ.DegFrac += DatI.DegFrac; }
if (DatJ.NIdQH.Empty()) { CmtyQH.DelKey(J); } // isolated community (done)
CmtyQH.DelKey(I);
return true;
}
