Re: [Boost-users] [BGL] vecS for vertex container and vertex index adjustments

Subject: Re: [Boost-users] [BGL] vecS for vertex container and vertex index adjustments
From: Ed Linde (edolinde_at_[hidden])
Date: 2012-09-26 16:09:32

Hi Jeremiah, 

I am facing a similar problem where I have to iterate through the vertices
of a graph and 
conditionally remove a lot of vertices. With the idea you mention of keeping
a VecS adjacency_list
graph + some external vertex property map indexed by vertex ID. And then
iterating with a for loop over 
"vertex IDs" instead of using the iterators, wouldn't the *remove_vertex*
anyway make the 
descriptors on the remaining vertices of the graph invalid? 

So in the end when I want to output the remaining graph, I might have
problems when I iterate
through the vertices. So is there an additional step of updating these
external vertex property maps
every time you delete a vertex using remove_vertex? Also do you think its a
good idea to process the 
vertices in a descending order? But I think the removal will mess up all the
vertex descriptors anyway, so 
I cannot save the output right? Just a bit confused I guess. I also do
shortest path calculations on the graph
 while removing vertices, so I cannot just have a flag set that can allow SP
algorithms to skip these vertices
 ( I think). So if you have any good work arounds let me know. :)

Cheers,
Ed

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