A quick update: I made the changes, but the performance improvement was slight (around 1 percent). I have identified, however, that the `BGL_FORALL_OUTEDGES_T(uPrime, e, g, UndirectedGraph)` loop is even worse when it comes to iterating through the entire map; toward the latter part of the computation, this loop iterates over more and more of the input graph's edges until the loop covers close to 100% of the edges.
I used that loop because with it, it is possible to run the algorithm without modifying or copying the input graph. I am now thinking that I really want to copy the input graph and make changes to the copy. So, I will be adding a "destructive" version of the `stoer_wagner_min_cut` function that will be used on copies. Users could also use the destructive version on a graph that they do not care about.
Version 0.5.5 has been uploaded to the Vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=stoer_wagner_min_cut-0.5.5.zip&directory=Algorithms/graph& The only substantive difference in this version is that it includes the code to build up a set of "assigned vertices", leading to the slight performance improvement that I was talking about on August 18. As far as producing a "destructive version", I tried out two variants. One utilized `clear_vertex` and the other utilized a different method of removing edges that needed to be removed as the algorithm encountered them. Interestingly, a benchmark program that I have been using takes 11 times longer to run when `clear_vertex` is used, and I don't know how much longer on the other version because I Ctrl+C it each time. These were unexpected results, but I guess that iterating through more and more of the edges as the computation progresses is a lot more efficient than removing edges from the input graph. Anyway, I believe that this new version has addressed all feedback that I have received so far.