protected void executeImpl() {
initKeys();
layerCount = 0;
bfsTraverser = Traverser.newBfs().notRepeatingEdges().build();
boolean exit = bfs(startNode);
if (!exit) {
for (Node n : graph.nodes()) {
if (!isVisited(n)) {
exit = bfs(n);
if (exit) {
break;
}
}
}
}
bfsTraverser = null;
}
// return true to break
protected boolean bfs(Node start) {
Object tree = new Object();
incTreeNumber();
markNodeTree(start, tree);
markNode(start, 0, null);
if (visitNewTree(start)) {
return true;
}
final boolean[] exit = new boolean[1];
PathIterator iterator = bfsTraverser.traverse(graph, start, direction).iterator();
while (iterator.hasNext()) {
Path path = iterator.next();
if (path.size() == 0) {
continue;
}
Edge e = path.tailEdge();
Node node = path.tailNode();
if (isVisited(node)) {
markEdge(e, EdgeType.crossEdge);
if (visitCrossEdge(path)) {
return true;
}
iterator.skipExplorationOfLastPath();
continue;
} else {
markEdge(e, EdgeType.treeEdge);
}
Node parent = e.opposite(node);
int level = getLevel(parent) + 1;
markNodeTree(node, getComponentIdentifier(parent));
markNode(node, level, e);
if (visitTreeEdge(path)) {
return true;
}
}
return false;
}