/**
*
* @return Edges
*/
public function getEdges()
{
$returnEdges = array();
// Create minimum spanning tree
$minimumSpanningTreeAlgorithm = new MstKruskal($this->graph);
$minimumSpanningTree = $minimumSpanningTreeAlgorithm->createGraph();
$alg = new SearchDepthFirst($minimumSpanningTree->getVertices()->getVertexFirst());
// Depth first search in minmum spanning tree (for the eulerian path)
$startVertex = NULL;
$oldVertex = NULL;
// connect vertices in order of the depth first search
foreach ($alg->getVertices() as $vertex) {
// get vertex from the original graph (not from the depth first search)
$vertex = $this->graph->getVertex($vertex->getId());
// need to clone the edge from the original graph, therefore i need the original edge
if ($startVertex === NULL) {
$startVertex = $vertex;
} else {
// get edge(s) to clone, multiple edges are possible (returns an array if undirected edge)
$returnEdges[] = $oldVertex->getEdgesTo($vertex)->getEdgeFirst();
}
$oldVertex = $vertex;
}
// connect last vertex with start vertex
// multiple edges are possible (returns an array if undirected edge)
$returnEdges[] = $oldVertex->getEdgesTo($startVertex)->getEdgeFirst();
return new Edges($returnEdges);
}
/**
* @expectedException UnexpectedValueException
*/
public function testNullGraphIsNotConsideredToBeConnected()
{
$graph = new Graph();
$alg = new Kruskal($graph);
$alg->getEdges();
}