[jgrapht-users] Suggestions for "shortest path with conditional nodes"?

[<org...@io...>]

Hello.

I'm modelling an abstract network. The network is represented by a
simple undirected graph (SimpleGraph, specifically). Vertices in the
graph represent networked devices, and the edges represent hardwired
network links.

I calculate routes in the network using DijkstraShortestPath. This
all works very well, but I'd now like to model nodes being optionally
on/off. If a node is "off", then it should be considered a dead end
when calculating routes. In other words, if a node is "off", then it
should be routed around if possible.

Does anyone have any suggestions as to how to get the shortest paths
when some nodes should conditionally be considered "invisible"?

In order to keep the code that deals with graphs simple, and because
the edges in the graph represent hardwired links, I don't really want
to remove vertices/edges when a node is switched off - the edges
carry a meaning beyond simply whether or not a packet can be routed
that way.

Right now, I'm leaning towards maintaining two graphs (one with the
physical links, the other with only the active nodes and links), but
I'd rather not do this as it obviously requires keeping two mutable
data structures synchronized.

M