@Override
public TraversalGraph<V, E> reconstructTraversalGraph() {
if (currentStartNode == null) {
throw new IllegalStateException(
"You must call #calculate before " + "reconstructing the traversal graph.");
}
TraversalGraph<V, E> traversalGraph =
new TraversalGraph<V, E>(graph.getEdgeFactory(), currentStartNode);
for (V v : graph.vertexSet()) {
Set<E> predEdges = (Set<E>) v.getPredecessorEdges();
for (E e : predEdges) {
V source = graph.getEdgeSource(e);
V target = graph.getEdgeTarget(e);
traversalGraph.addVertex(source);
traversalGraph.addVertex(target);
if (v.equals(source)) {
traversalGraph.addEdge(target, source).setBaseGraphEdge(e);
} else if (v.equals(target)) {
traversalGraph.addEdge(source, target).setBaseGraphEdge(e);
} else {
throw new IllegalStateException(
"A vertex has a predecessor " + "edge not ending on itself.");
}
}
}
return traversalGraph;
}
@Test
public void testBFSFromVertexEight() {
bfs.calculate(v8);
assertTrue(graph.getVertex(8).getDistance() == 0);
assertTrue(graph.getVertex(5).getDistance() == 1);
assertTrue(graph.getVertex(6).getDistance() == 1);
assertTrue(graph.getVertex(7).getDistance() == 1);
assertTrue(graph.getVertex(4).getDistance() == 2);
assertTrue(graph.getVertex(3).getDistance() == 3);
assertTrue(graph.getVertex(2).getDistance() == 4);
assertTrue(graph.getVertex(1).getDistance() == 5);
sPT = bfs.reconstructTraversalGraph();
assertTrue(sPT.getRoot().equals(v8));
assertTrue(sPT.edgeSet().size() == 8);
assertTrue(sPT.containsEdge(v8, v7));
assertTrue(sPT.containsEdge(v8, v5));
assertTrue(sPT.containsEdge(v5, v4));
assertTrue(sPT.containsEdge(v8, v6));
assertTrue(sPT.containsEdge(v6, v4));
assertTrue(sPT.containsEdge(v4, v3));
assertTrue(sPT.containsEdge(v3, v2));
assertTrue(sPT.containsEdge(v2, v1));
}
