Re: [Boost-users] [graph] set of edges

Subject: Re: [Boost-users] [graph] set of edges
From: Andrew Sutton (andrew.n.sutton_at_[hidden])
Date: 2009-03-17 11:56:24

>
> So what's the recommendation?  The Known Bugs page says that anything
> other than listS is not guaranteed to work for EdgeList, but if
> std::list has O(n) size(), then num_edges()/num_vertices() becomes
> O(n)?
>
> Or were you talking about OutEdgeList?

Both. Any selector of listS will cause corresponding functions that use
size() to be linear. I'm just giving a reminder since it's bitten me before
:)

On a side note, there are two new graph classes in trunk
([un]directed_graph) that wrap listS selected adjacency lisst and provide
O(1) num_* and *degree functions. They also provide builtin index maps and
functinality for renumbering vertices/edges. They aren't really documented
yet and certainly won't be part of the release for a while.

> Are there *known* cases where vecS is bug-free when used for the
> EdgeList?  In my case, I know the total number of edges ahead of time,
> and no edges or vertices will ever be removed.

I think the general rule is that if you don't need to remove anything, you
can use vecS wherever you want. It's the removals that really kill the
adjacency list.

Andrew Sutton
andrew.n.sutton_at_[hidden]