Re: [Boost-users] [BGL]Problems in the shortest pair algorithms.

From: Doug Gregor (dgregor_at_[hidden])
Date: 2006-02-27 10:38:40

On Feb 20, 2006, at 9:16 AM, Peter Gerell wrote:

> Hi,
> I have reported some problems with the johnson_all_pairs_shortest_paths
> and floyd_warshall_all_pairs_shortest_paths algorithms.
>
> What is the correct way to report these problems. I made some posts to 
> the
> list last week, but didn't get any response.
> Perhaps this should go on the developer mailing list instead?

You've found the right place (and the right person), but I have been on 
the road an unable to respond.

> However, the problems I have noticed are:
>   Floyd-Warshall:
>     1. std::min is used instead of the functor passed to as teh
> distance_compare parameter at several places
>     2. The distance map is initialized with 0 instead of zero.

Yep, those are bugs. I believe I've now fixed them in Boost CVS.

>   Johnson:
>     3. std::numeric_limits<DT>::max() is used instead of the 
> distance_inf
> parameter.
>     4. The distance_combine and distance_compare parameters are not 
> used.
> The bellman_ford_shortest_paths algorithm is called with std::less and
> closed_plus.

Also bugs. I think I've just fixed these as well.

Thanks for reporting these bugs!

        Doug