private boolean depthFirstSearchRecursive(
VertexType vertex, VertexType fromVertex, PreWorkPostWorkHandler<VertexType> handler)
throws InvalidVertexException {
// TODO:Implementing non-recursive version
// int vertexId = vertex.getId();
vertex.setMark(true);
if (handler != null) if (handler.doPreWork(fromVertex, vertex)) return true;
dispatchEvent(new PreWorkEvent<VertexType, EdgeType>(fromVertex, vertex, graph));
EventUtils.algorithmStep(this, "visit: " + vertex.getId());
VertexType lastInDepthVertex = vertex;
for (VertexType i : graph) {
if (graph.isEdge(vertex, i)) {
if (!i.getMark()) {
lastInDepthVertex = i;
if (depthFirstSearchRecursive(i, vertex, handler)) return true;
}
}
}
dispatchEvent(new PostWorkEvent<VertexType, EdgeType>(lastInDepthVertex, vertex, graph));
EventUtils.algorithmStep(this, "leave: " + vertex.getId());
if (handler != null) if (handler.doPostWork(lastInDepthVertex, vertex)) return true;
return false;
}
private void informVertices() {
if (isSubgraph) superGraph.informVertices();
for (VertexType v : this) {
v.informNewSubgraph();
}
}
/**
* Get new id for a new subgraph;
*
* @param b
*/
public int getNewSubgraphIndex() {
if (isSubgraph) return superGraph.getNewSubgraphIndex();
return lastSubgraphIndex + 1;
}
/**
* Sets the graph as a subgraph.
*
* @param b
*/
public void registerSubgraph(BaseGraph<VertexType, EdgeType> superGraph) {
isSubgraph = true;
this.superGraph = superGraph;
superGraph.informVertices();
}
static <Vertex extends BaseVertex, Edge extends BaseEdge<Vertex>> Vector<Edge> convertToDag(
BaseGraph<Vertex, Edge> graph) {
System.out.println("start convertToDag");
System.out.println(graph.getEdgesCount());
// copied from Dag.finACycle
byte[] mark = new byte[graph.getVerticesCount()];
BaseVertex[] V = graph.getVertexArray();
BaseVertex[] parent = new BaseVertex[mark.length];
BaseVertex[] root = new BaseVertex[mark.length];
Integer[] height = new Integer[mark.length];
LibraryUtils.falsifyVertexMarks(graph);
// start from one vertex and go to it's neighbors [BFS], continue until
// you meet a MARKed vertex
HashSet<Vertex> visitedVertices = new HashSet<Vertex>();
LinkedList<Vertex> bfsStack = new LinkedList<Vertex>();
Vertex cycleStart = null;
Vertex cycleEnd = null;
// visitedVertices.add(current);
int scan = 0;
int counter = 0;
Vertex current;
// perform a nonrecursive dfs
for (scan = 0; scan < V.length; scan++) {
Vertex u = (Vertex) V[scan];
if (!u.getMark()) {
/* Start a new search from u */
bfsStack.addFirst(u);
root[u.getId()] = u;
height[u.getId()] = 0;
while (!bfsStack.isEmpty()) {
Vertex v = bfsStack.removeFirst();
if (!v.getMark()) {
v.setMark(true);
counter++;
for (Vertex w : graph.getNeighbors(v))
if (!w.getMark()) {
bfsStack.push(w);
parent[w.getId()] = v;
root[w.getId()] = u;
height[w.getId()] = height[v.getId()] + 1;
}
}
}
}
}
Vector<Edge> ret = new Vector<Edge>();
// try to find backedges
for (Edge e : graph.edges()) {
int src = e.source.getId();
int trg = e.target.getId();
if (root[src] == root[trg] && height[src] > height[trg]) {
ret.add(e);
System.out.println(ret.size());
// cycleStart = e.target;
// cycleEnd = e.source;
//
//
// current = cycleEnd;
// LinkedList<Vertex> ret = new LinkedList<Vertex>();
// ret.addFirst(current);
// while (current != null && current != cycleStart) {
// current = (Vertex) parent[current.getId()];
// ret.addFirst(current);
// }
// if (current != null)
// return;
}
}
return ret;
}
