void FUPSSimple::getSpanTree(GraphCopy &GC, List<edge> &delEdges, bool random)
{
if (GC.numberOfNodes() == 1)
return; // nothing to do
node s;
hasSingleSource(GC, s);
NodeArray<bool> visited(GC, false);
EdgeArray<bool> isTreeEdge(GC,false);
List<node> toDo;
//mark the incident edges e1..e_i of super source s and the incident edges of the target node of the edge e1.._e_i as tree edge.
visited[s] = true;
for(adjEntry adj : s->adjEdges) {
isTreeEdge[adj] = true;
visited[adj->theEdge()->target()];
for(adjEntry adjTmp : adj->theEdge()->target()->adjEdges) {
isTreeEdge[adjTmp] = true;
node tgt = adjTmp->theEdge()->target();
if (!visited[tgt]) {
toDo.pushBack(tgt);
visited[tgt] = true;
}
}
}
//traversing with dfs
for(node start : toDo) {
for(adjEntry adj : start->adjEdges) {
node v = adj->theEdge()->target();
if (!visited[v])
dfs_visit(GC, adj->theEdge(), visited, isTreeEdge, random);
}
}
// delete all non tree edgesEdges to obtain a span tree
List<edge> l;
for(edge e : GC.edges) {
if (!isTreeEdge[e])
l.pushBack(e);
}
while (!l.empty()) {
edge e = l.popFrontRet();
delEdges.pushBack(GC.original(e));
GC.delEdge(e);
}
}
void FeasibleUpwardPlanarSubgraph::getSpanTree(GraphCopy &GC, List<edge> &delEdges, bool random, bool multisource)
{
delEdges.clear();
if (GC.numberOfNodes() == 1)
return; // nothing to do
node s;
hasSingleSource(GC, s);
NodeArray<bool> visited(GC, false);
EdgeArray<bool> isTreeEdge(GC,false);
List<node> toDo;
// the original graph is a multisource graph. The sources are connected with the super source s.
// so do not delete the incident edges of s
if (multisource){
// put all incident edges of the source to treeEdges
for(adjEntry adj : s->adjEdges) {
isTreeEdge[adj->theEdge()] = true;
visited[adj->theEdge()->target()];
toDo.pushBack(adj->theEdge()->target());
}
}
else
toDo.pushBack(s);
//traversing with dfs
for(node start : toDo) {
for(adjEntry adj : start->adjEdges) {
node v = adj->theEdge()->target();
if (!visited[v])
dfs_visit(GC, adj->theEdge(), visited, isTreeEdge, random);
}
}
// delete all non tree edgesEdges to obtain a span tree
List<edge> l;
for(edge e : GC.edges) {
if (!isTreeEdge[e])
l.pushBack(e);
}
while (!l.empty()) {
edge e = l.popFrontRet();
delEdges.pushBack(GC.original(e));
GC.delEdge(e);
}
}
void FeasibleUpwardPlanarSubgraph::getSpanTree(GraphCopy &GC, List<edge> &delEdges, bool random, bool multisource)
{
delEdges.clear();
if (GC.numberOfNodes() == 1)
return; // nothing to do
node s;
hasSingleSource(GC, s);
NodeArray<bool> visited(GC, false);
EdgeArray<bool> isTreeEdge(GC,false);
List<node> toDo;
// the original graph is a multisource graph. The sources are connected with the super source s.
// so do not delete the incident edges of s
if (multisource){
// put all incident edges of the source to treeEdges
adjEntry adj;
forall_adj(adj, s) {
isTreeEdge[adj->theEdge()] = true;
visited[adj->theEdge()->target()];
toDo.pushBack(adj->theEdge()->target());
}
}