import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
protected void printSpanningTree()
{
	logger.info("In Spanning Tree " );
	KruskalMinimumSpanningTree<DBCMVertex, DBCMEdge> ins = new KruskalMinimumSpanningTree<DBCMVertex, DBCMEdge>(graph);
	
	logger.info("Number of vertices " + graph.vertexSet().size());
	logger.info(" Edges  " + ins.getEdgeSet().size());
	Iterator <DBCMEdge> csIterator = ins.getEdgeSet().iterator();
	int count = 0;
	while(csIterator.hasNext())
	{
			DBCMEdge vert = csIterator.next();
			//writeStatus("Set " + count + ">>>> " + vert.getProperty(Constants.EDGE_NAME));
			//logger.info("Set " + count + ">>>> " + vert.getProperty(Constants.EDGE_NAME));
	}
	count++;
}
 

import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
/**
 * Method actionPerformed.
 *
 * @param e ActionEvent
 */
@Override
public void actionPerformed( ActionEvent e ) {

	// gets the view from the playsheet
	// gets the jGraphT graph
	// runs the kruskal on it
	// Creates the edges and sets it on the edge painter
	// repaints it
	// I cannot add this to the interface because not all of them will be forced to have it
	// yes, which means the menu cannot be generic too - I understand
	logger.debug( "Getting the base graph" );
	Graph graph = ps.asSimpleGraph();
	KruskalMinimumSpanningTree<SEMOSSVertex, SEMOSSEdge> kmst
			= new KruskalMinimumSpanningTree<>( graph );

	EdgeStrokeTransformer tx = (EdgeStrokeTransformer) ps.getView().getRenderContext()
			.getEdgeStrokeTransformer();
	tx.setSelected( kmst.getEdgeSet() );

	// repaint it
	ps.getView().repaint();
	int originalSize = ps.getVisibleGraph().getEdgeCount();
	int shortestPathSize = kmst.getEdgeSet().size();
	GuiUtility.showMessage( "Minimum Spanning Tree uses " + shortestPathSize
			+ " edges out of " + originalSize + " original edges" );
}
 

import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
public Multigraph<GameRoom, NoDuplicateEdge> generateMinimalSpanningTree(Array<GameCell> cells, float remainingEdgesMultiplier) {
        Gdx.app.log("GraphGenerator", "----------------- Generating minimal spanning tree -----------------");

        Array<GameRoom> rooms = GameMap.extractRooms(cells);
        ShortArray trianglesIndices = generateTrianglesIndices(cells);

        Multigraph<GameRoom, NoDuplicateEdge> graph = getGraphFromTriangulation(trianglesIndices, rooms);

        Set<NoDuplicateEdge> minEdges = new KruskalMinimumSpanningTree(graph).getMinimumSpanningTreeEdgeSet();
//        Set<NoDuplicateEdge> minEdges = new PrimMinimumSpanningTree(graph).getMinimumSpanningTreeEdgeSet();

        minimumSpanningTreeFromGraph(graph, minEdges, remainingEdgesMultiplier);

        Gdx.app.log("GraphGenerator", "  --> Graph is now a minimal spanning tree. Edge count: " + graph.edgeSet().size());

        return graph;
    }
 

import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
public KruskalMinimumSpanningTree<Room, Hallway> getMST() {
    return new KruskalMinimumSpanningTree<Room, Hallway>(getFullGraph());
}
 

import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
/**
	 * Find the minimal spanning tree, T1, of G1. (If there are several minimal spanning trees, pick an arbitrary one.)
	 * @param g1
	 * @return
	 */
	private WeightedMultigraph<Node, DefaultLink> step2(Pseudograph<Node, DefaultLink> g1) {

		logger.debug("<enter");

		KruskalMinimumSpanningTree<Node, DefaultLink> mst =
            new KruskalMinimumSpanningTree<Node, DefaultLink>(g1);

//    	logger.debug("Total MST Cost: " + mst.getSpanningTreeCost());

        Set<DefaultLink> edges = mst.getEdgeSet();

		WeightedMultigraph<Node, DefaultLink> g2 = 
			new WeightedMultigraph<Node, DefaultLink>(DefaultLink.class);
		
		List<DefaultLink> edgesSortedById = new ArrayList<DefaultLink>();
		
		for (DefaultLink e : edges) 
			edgesSortedById.add(e);
		
		Collections.sort(edgesSortedById);
		
		for (DefaultLink edge : edgesSortedById) {
			g2.addVertex(edge.getSource());
			g2.addVertex(edge.getTarget());
			g2.addEdge( edge.getSource(), edge.getTarget(), edge); 
		}
		
		logger.debug("exit>");

		return g2;
	}
 

import org.jgrapht.alg.KruskalMinimumSpanningTree; //导入依赖的package包/类
/**
	 * Find the minimal spanning tree, Ts, of Gs. (If there are several minimal spanning trees, pick an arbitrary one.)
	 * @param g3
	 * @return
	 */
	private WeightedMultigraph<Node, DefaultLink> step4(WeightedMultigraph<Node, DefaultLink> g3) {

		logger.debug("<enter");

		KruskalMinimumSpanningTree<Node, DefaultLink> mst =
            new KruskalMinimumSpanningTree<Node, DefaultLink>(g3);

//    	logger.debug("Total MST Cost: " + mst.getSpanningTreeCost());

        Set<DefaultLink> edges = mst.getEdgeSet();

		WeightedMultigraph<Node, DefaultLink> g4 = 
			new WeightedMultigraph<Node, DefaultLink>(DefaultLink.class);
		
		List<DefaultLink> edgesSortedById = new ArrayList<DefaultLink>();
		
		for (DefaultLink e : edges) 
			edgesSortedById.add(e);
		
		Collections.sort(edgesSortedById);
		
		for (DefaultLink edge : edgesSortedById) {
			g4.addVertex(edge.getSource());
			g4.addVertex(edge.getTarget());
			g4.addEdge( edge.getSource(), edge.getTarget(), edge); 
		}
		
		logger.debug("exit>");

		return g4;
	}