/**
* Checks for any coincident ends of edges.
*
* @return a List of the coincident edges, if any
*/
public Set checkCoincidentEdges() {
Set coincidentEdges = new HashSet();
for (Iterator i = nodeIterator(); i.hasNext(); ) {
Node node = (Node) i.next();
DirectedEdgeStar deStar = node.getOutEdges();
DirectedEdge firstDE = null;
DirectedEdge prevDE = null;
for (Iterator j = deStar.iterator(); j.hasNext(); ) {
DirectedEdge de = (DirectedEdge) j.next();
if (firstDE == null) firstDE = de;
if (prevDE != null) {
if (isCoincidentEdge(de, prevDE)) {
coincidentEdges.add(de.getEdge());
coincidentEdges.add(prevDE.getEdge());
}
}
prevDE = de;
}
if (firstDE != prevDE)
if (isCoincidentEdge(firstDE, prevDE)) {
coincidentEdges.add(firstDE.getEdge());
coincidentEdges.add(prevDE.getEdge());
}
}
return coincidentEdges;
}
public void traverseBFS(Node<N, E> startingNode, BFSTraversalVisitor tv, boolean longestPath) {
if (longestPath) {
markReachable(startingNode);
}
for (Node<N, E> n : getNodes()) {
n.setVisited(false);
n.setActive(false);
}
Queue<Node<N, E>> queue = new LinkedList<Node<N, E>>();
queue.add(startingNode);
startingNode.setVisited(true);
int layer = 0;
Node<N, E> lastOfLayer = startingNode;
Node<N, E> lastAdded = null;
while (!queue.isEmpty()) {
Node<N, E> current = queue.poll();
tv.visitNode(current, layer);
current.setActive(false);
for (Edge<N, E> e : current.getOutEdges()) {
if (!e.getDest().isVisited()) {
boolean allow = true;
if (longestPath) {
for (Node<N, E> pred : e.getDest().getPredecessors()) {
if ((!pred.isVisited() || pred.isActive()) && pred.isReachable()) {
allow = false;
break;
}
}
}
if (allow) {
queue.offer(e.getDest());
lastAdded = e.getDest();
e.getDest().setVisited(true);
e.getDest().setActive(true);
}
}
}
if (current == lastOfLayer && !queue.isEmpty()) {
lastOfLayer = lastAdded;
layer++;
}
}
}
private void traverse(DFSTraversalVisitor tv, Node<N, E> n) {
if (!n.isVisited()) {
n.setVisited(true);
n.setActive(true);
tv.visitNode(n);
for (Edge<N, E> e : n.getOutEdges()) {
Node<N, E> next = e.getDest();
if (next.isActive()) {
tv.visitEdge(e, true);
} else {
if (tv.visitEdge(e, false)) {
traverse(tv, next);
}
}
}
n.setActive(false);
}
}
