On Fri, Feb 4, 2011 at 3:26 PM, Mike Hansen <mhan...@gmail.com> wrote:
> On Fri, Feb 4, 2011 at 11:56 PM, Johannes <dajo.m...@web.de> wrote:
>> Hi list
>> how can i add a new edge (a->b) to a given graph G (n.n. connected),
>> just in the case that there is no path (a -> ... -> b) before?
>
> You should use "shortest_path" which uses Dijkstra's algorithm under the hood.
>
> if g.shortest_path('a', 'b') == []:
> g.add_edge('a', 'b')
Of course finding the shortest path may be (almost) as expensive as
finding all of them... If you're doing this for a lot of edges you
might want to break it up into components, then the test would be
easy. It would be cool if all_paths were an iterator and you could
just ask for the first one.
- Robert
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