[jgrapht-users] Non-determinstic getSpanningTreeEdge call

[Idan M. <ida...@gm...>]

Hi everyone,

I'm using the ClosestFirst iterator to calculate a weighted BFS.
The problem is, I get non-deterministic results with calling
getSpanningTreeEdge for the same graph.
Any idea how I can make it deterministic? It's not mentioned in the
documentation.

Here's the code snippet:

private static synchronized NavigationGraph findSpanningTree(NavigationGraph
graph)
    {
        // Run BFS starting from the root node and create a result graph
        DirectedGraph<NavigationGraphNode, NavigationGraphEdge> tree =
            new DefaultDirectedGraph<NavigationGraphNode,
NavigationGraphEdge>(NavigationGraphEdge.class);
        tree.addVertex(graph.getRoot());

        ClosestFirstIterator<NavigationGraphNode, NavigationGraphEdge>
iterator =
            new ClosestFirstIterator<NavigationGraphNode,
NavigationGraphEdge>(graph.getGraph(), graph.getRoot());

        while (iterator.hasNext())
        {
           NavigationGraphNode currVertex = iterator.next();

            // Add target vertex and edge to tree
            tree.addVertex(currVertex);
            NavigationGraphEdge edge =
iterator.getSpanningTreeEdge(currVertex);

            if (edge != null)
            {
                tree.addEdge(graph.getGraph().getEdgeSource(edge),
currVertex, edge);
            }
        }

        return (new NavigationGraph(tree, graph.getRoot()));
    }