/*
* Returns the active c-node of RBC list containing "u".
* Traverses only nodes with label_b <= dfspos_num[w].
* Let z be the first element of RBC.
* All traversed nodes, but z, are inserted in "nl".
* Pre-conditions:
* - "u" is not the 1st element in RBC list;
* - ptritem[u] is the pointer to the item containing "u";
* - "u" is a node that is an ancestor of a neighbor of w;
* - state[v] == NOT_VISITED for each node v in RBC list that was not
* traversed.
*/
node PlanarityTestImpl::findActiveCNode(node u, node w, list<node> &nl) {
list<node> traversedNodesInRBC;
assert(isCNode(parent.get(u.id)));
if (state.get(u.id) != NOT_VISITED) {
assert(!isCNode(parent.get(parent.get(u.id).id)));
return parent.get(u.id);
}
BmdLink<node> *it1 = ptrItem.get(u.id); // ptrItem[u];
assert(it1 != nullptr);
state.set(u.id, VISITED_IN_RBC);
traversedNodesInRBC.push_back(u);
BmdLink<node> *it = searchRBC(1, it1, w, traversedNodesInRBC);
if (it == nullptr)
it = searchRBC(0, it1, w, traversedNodesInRBC);
assert(it != nullptr);
node v = it->getData();
node cNode;
if (it->prev() != nullptr && it->succ() != nullptr)
cNode = parent.get(v.id); // path compressed;
else
cNode = activeCNode[it];
assert(cNode != NULL_NODE);
node first = RBC[cNode].firstItem()->getData();
// path compression;
// forall(v, traversedNodesInRBC)
for (list<node>::iterator it = traversedNodesInRBC.begin(); it != traversedNodesInRBC.end();
++it) {
if (*it != first) {
if (*it != u)
nl.push_back(v);
parent.set((*it).id, cNode);
} else
state.set((*it).id, NOT_VISITED);
}
return cNode;
}
//=================================================================
BmdLink<node> *PlanarityTestImpl::searchRBC(int dir, BmdLink<node> *it, node n,
list<node> &traversedNodesInRBC) {
if (it != nullptr && (it->prev() == nullptr || it->succ() == nullptr)) // 1st or last item in RBC;
return it;
BmdLink<node> *prev = it;
BmdLink<node> *aux1 = it->prev();
BmdLink<node> *aux2 = it->succ();
if (dir == 1) {
// leda_swap(aux1, aux2);
BmdLink<node> *tmp = aux1;
aux1 = aux2;
aux2 = tmp;
}
it = aux1;
node u = it->getData();
int b = labelB.get(u.id);
while (it != nullptr && (b <= dfsPosNum.get(n.id) || dir != 1) &&
state.get(u.id) == NOT_VISITED) {
aux1 = it->prev();
if (aux1 == prev)
aux1 = it->succ();
prev = it;
it = aux1;
u = prev->getData();
state.set(u.id, VISITED_IN_RBC);
traversedNodesInRBC.push_back(u);
if (it != nullptr) {
u = it->getData();
b = labelB.get(u.id);
}
}
if (it == nullptr)
return prev;
else if (state.get(u.id) != NOT_VISITED || (it->prev() == nullptr || it->succ() == nullptr))
return it;
else
return nullptr;
}
//=================================================================
void PlanarityTestImpl::addOldCNodeRBCToNewRBC(node oldCNode, node, node n, node n1, node n2,
tlp::BmdList<node> &nodeList) {
// compress RBC[oldCNode]:
// removes all nodes v in RBC[oldCNode] s.t. label_b[v] < dfspos_num[n]
// or v = parent[oldCNode].
BmdLink<node> *firstItem = RBC[oldCNode].firstItem();
BmdLink<node> *predItem = RBC[oldCNode].cyclicPred(firstItem, nullptr);
BmdLink<node> *succItem = RBC[oldCNode].cyclicSucc(firstItem, nullptr);
node predNode = predItem->getData();
node succNode = succItem->getData();
node ul;
node ur;
// goes to the left;
while (labelB.get(predNode.id) == dfsPosNum.get(n.id) && predNode != n1 && predNode != n2) {
if (!ul.isValid())
ul = predNode;
BmdLink<node> *tmp = predItem;
predItem = RBC[oldCNode].cyclicPred(predItem, firstItem);
predNode = predItem->getData();
RBC[oldCNode].delItem(tmp);
}
// goes to right;
while (labelB.get(succNode.id) == dfsPosNum.get(n.id) && succNode != n1 && succNode != n2) {
if (!ur.isValid())
ur = succNode;
BmdLink<node> *tmp = succItem;
succItem = RBC[oldCNode].cyclicSucc(succItem, firstItem);
succNode = succItem->getData();
RBC[oldCNode].delItem(tmp);
}
RBC[oldCNode].delItem(RBC[oldCNode].firstItem());
// endpoint to correctly concatentates with RBC[new_cnode];
node first = n1;
if (!n1.isValid()) {
if (ul.isValid())
first = predNode;
else
first = succNode;
}
// note that oldCNode may have flipped;
if (RBC[oldCNode].lastItem()->getData() == first)
RBC[oldCNode].reverse();
// reoves n1 and n2 from RBC[oldCNode];
if (n1.isValid()) {
RBC[oldCNode].delItem(RBC[oldCNode].firstItem());
}
if (n2.isValid()) {
RBC[oldCNode].delItem(RBC[oldCNode].lastItem());
}
nodeList.conc(RBC[oldCNode]);
}
/*
* Moves embedding of oldCNode to embList - note that oldCNode may
* flip - and embeds all edges in path from w (starting with a back-edge from w) and
* ending in a node in RBC[oldCNode].
* All representants to be embedded later is ordered and inserted in toEmbedLater.
* emb_back_edges_out_w is false only in case of 2 terminal
* nodes, for one of the two terminals (see calculate_partial_embedding).
* Preconditions:
* - for a back-edge e, if u is representant of source(e) and u in RBC[oldCNode],
* then e is in list b_edges_repres[u];
* - the first element in list RBC[oldCNode] is parent[oldCNode];
* - if u != nil then u is a node in RBC[oldCNode] s.t. label_b[u] > dfspos_num[w]
* and there exists a path from u to w that doesn't contain any node in the
* 2-connected component represented by oldCNode, except u.
*/
void PlanarityTestImpl::addOldCNodeToEmbedding(bool embBackEdgesOutW,
Graph *sG,
node w,
node oldCNode,
node u,
map<node, list<edge> >& bEdgesRepres,
list<node>& traversedNodes,
list<node>& toEmbedLater,
tlp::BmdList<edge>& embList) {
BmdLink<node> *it = RBC[oldCNode].firstItem();
BmdLink<node> *itl = RBC[oldCNode].cyclicPred(it, 0);
BmdLink<node> *itr = RBC[oldCNode].cyclicSucc(it, 0);
node jl = itl->getData();
node jr = itr->getData();
list<node> listNodesL, listNodesR;
// goes to the left;
BmdLink<node> *aux = NULL;
BmdLink<node> *s = it;
while (labelB.get(jl.id) <= dfsPosNum.get(w.id)) {
assert(jl != u);
if (labelB.get(jl.id) == dfsPosNum.get(w.id))
listNodesL.push_back(jl);
aux = itl;
itl = RBC[oldCNode].cyclicPred(itl, s);
s = aux;
jl = itl->getData();
}
// goes to the right;
BmdLink<node> *p = it;
while (labelB.get(jr.id) <= dfsPosNum.get(w.id)) {
assert(jr != u);
if (labelB.get(jr.id) == dfsPosNum.get(w.id))
listNodesR.push_back(jr);
aux = itr;
itr = RBC[oldCNode].cyclicSucc(itr, p);
p = aux;
jr = itr->getData();
}
// checks if need to flip oldCNode;
// u == nil when oldCNode is a terminal node;
bool flipped = ((!listNodesL.empty() && (jl == u || u == NULL_NODE))
|| (jr != u && u != NULL_NODE));
if (flipped)
listNodesL.swap(listNodesR);
// embeds all back-edges in oldCNode;
// listNodesR.reverse_items();
listNodesR.reverse();
node t;
//forall(t, listNodesR)
for (list<node>::iterator it = listNodesR.begin() ;
it != listNodesR.end() ; it++) {
t = *it;
embedBackEdges(embBackEdgesOutW, sG, t, traversedNodes,
bEdgesRepres[t], embList);
}
if (flipped)
embedList[oldCNode].reverse();
embedList[oldCNode].conc(embList);
embedList[oldCNode].swap(embList);
//toEmbedLater.conc(listNodesL, LEDA::before);
toEmbedLater.splice(toEmbedLater.begin(), listNodesL);
}