// Add the fact that v1 and v2 are equivalent
// return true if v1 was not already equivalent to v2
// and false if v1 was already equivalent to v2
bool SetEquivalent(int v1, int v2)
{
bool const already_equiv = false;
if (v1 == v2)
return already_equiv;
ensureElementExists(v1);
ensureElementExists(v2);
const int r1 = disjoint_sets_.find_set(v1);
const int r2 = disjoint_sets_.find_set(v2);
if (r1 == r2)
return already_equiv;
root_set_map_t::const_iterator it1 = rootSetMap_.find(r1);
assert(it1 != rootSetMap_.end());
std::list<int> s1 = it1->second;
root_set_map_t::const_iterator it2 = rootSetMap_.find(r2);
assert(it2 != rootSetMap_.end());
std::list<int> s2 = it2->second;
s1.splice(s1.begin(), s2); // union the related sets
disjoint_sets_.link(r1, r2); // union the disjoint sets
// associate the combined related set with the new root
int const new_root = disjoint_sets_.find_set(v1);
if (new_root != r1) {
rootSetMap_.erase(it1);
} else {
rootSetMap_.erase(it2);
}
rootSetMap_[new_root] = s1;
return !already_equiv;
}
void
dynamic_connected_components(EdgeListGraph& g, DisjointSets& ds)
{
typename graph_traits<EdgeListGraph>::edge_iterator e, end;
for (tie(e,end) = edges(g); e != end; ++e)
ds.link(source(*e,g),target(*e,g));
}
//compute bag affiliation for all vertices
//store result in m_bagindex
void ClusterAnalysis::computeBags() {
const Graph &G = m_C->constGraph();
// Storage structure for results
m_bagindex.init(G);
// We use Union-Find for chunks and bags
DisjointSets<> uf;
NodeArray<int> setid(G); // Index mapping for union-find
#if 0
node* nn = new node[G.numberOfNodes()]; // dito
#endif
// Every cluster gets its index
ClusterArray<int> cind(*m_C);
// We store the lists of cluster vertices
List<node>* clists = new List<node>[m_C->numberOfClusters()];
int i = 0;
// Store index and detect the current leaf clusters
List<cluster> ccleafs;
ClusterArray<int> unprocessedChildren(*m_C); //processing below: compute bags
for(cluster c : m_C->clusters)
{
cind[c] = i++;
if (c->cCount() == 0) ccleafs.pushBack(c);
unprocessedChildren[c] = c->cCount();
}
// Now we run through all vertices, storing them in the parent lists,
// at the same time, we initialize m_bagindex
for(node v : G.nodes)
{
// setid is constant in the following
setid[v] = uf.makeSet();
// Each vertex v gets its own ClusterArray that stores v's bag index per cluster.
// See comment on use of ClusterArrays above
m_bagindex[v] = new ClusterArray<int>(*m_C,DefaultIndex, m_C->maxClusterIndex()+1);//m_C->numberOfClusters());
cluster c = m_C->clusterOf(v);
// Push vertices in parent list
clists[cind[c]].pushBack(v);
}
// Now each clist contains the direct vertex descendants
// We process the clusters bottom-up, compute the chunks
// of the leafs first. At each level, for a cluster the
// vertex lists of all children are concatenated
// (could improve this by having an array of size(#leafs)
// and concatenating only at child1), then the bags are
// updated as follows: chunks may be linked by exactly
// the edges with lca(c) ie the ones in m_lcaEdges[c],
// and bags may be built by direct child clusters that join chunks.
// While concatenating the vertex lists, we can check
// for the vertices in each child if the uf number is the same
// as the one of a first initial vertex, otherwise we join.
// First, lowest level clusters are processed: All chunks are bags
OGDF_ASSERT(!ccleafs.empty());
while (!ccleafs.empty()){
const cluster c = ccleafs.popFrontRet();
Skiplist<int*> cbags; //Stores bag indexes ocurring in c
auto storeResult = [&] {
for (node v : clists[cind[c]]) {
int theid = uf.find(setid[v]);
(*m_bagindex[v])[c] = theid;
if (!cbags.isElement(&theid)) {
cbags.add(new int(theid));
}
// push into list of outer active vertices
if (m_storeoalists && isOuterActive(v, c)) {
(*m_oalists)[c].pushBack(v);
}
}
(*m_bags)[c] = cbags.size(); // store number of bags of c
};
if (m_storeoalists){
//no outeractive vertices detected so far
(*m_oalists)[c].clear();
}
//process leafs separately
if (c->cCount() == 0) {
//Todo could use lcaEdges list here too, see below
for (node u : c->nodes)
{
for(adjEntry adj : u->adjEntries) {
node w = adj->twinNode();
if (m_C->clusterOf(w) == c)
{
uf.link(uf.find(setid[u]),uf.find(setid[w]));
}
}
}
// Now all chunks in the leaf cluster are computed
// update for parent is done in the else case
storeResult();
}
else {
// ?We construct the vertex list by concatenating
// ?the lists of the children to the current list.
// We need the lists for storing the results efficiently.
// (Should be slightly faster than to call clusterNodes each time)
// Bags are either links of chunks by edges with lca==c
// or links of chunk by child clusters.
// Edge links
for(edge e : (*m_lcaEdges)[c]) {
uf.link(uf.find(setid[e->source()]),uf.find(setid[e->target()]));
}
// Cluster links
for(cluster cc : c->children)
{
//Initial id per child cluster cc: Use value of first
//vertex, each time we encounter a different value in cc,
//we link the chunks
//add (*itcc)'s vertices to c's list
ListConstIterator<node> itvc = clists[cind[cc]].begin();
int inid;
if (itvc.valid()) inid = uf.find(setid[*itvc]);
while (itvc.valid())
{
int theid = uf.find(setid[*itvc]);
if (theid != inid)
uf.link(inid,theid);
clists[cind[c]].pushBack(*itvc);
++itvc;
}
}
storeResult();
}
// Now we update the status of the parent cluster and,
// in case all its children are processed, add it to
// the process queue.
if (c != m_C->rootCluster())
{
OGDF_ASSERT(unprocessedChildren[c->parent()] > 0);
unprocessedChildren[c->parent()]--;
if (unprocessedChildren[c->parent()] == 0) ccleafs.pushBack(c->parent());
}
}
// clean up
delete[] clists;
}