Re: [Boost-users] [BGL] Converting between adjacency_list with listS and vecS

Hi Justin, Thanks for the tip / source code! I thought the library would have a built-in copy constructor for converting between different types, but I guess not. On another note, since this method gives an isomorphic graph, all the properties must be copied over manually, correct? I think I'm only using vertex_name_t which is an internal property, but.. hmm.. Thanks again! Ethan On Wed, Jul 22, 2009 at 2:04 PM, Justin Leonard wrote:

Ethan Kim writes:

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Hi all,The long standing question I've had for BGL is how to easily

convert a graph (using adjacency_list) from listS as vertex list to vecS. (And vice versa) I understand why there needs to be 2 different implementations depending on different uses of algorithms. But is there an easy way to convert them back and forth?Any tip would be much appreciated.Thanks,

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Do you mean given Graph A using listS you want to produce Graph B using vecS? How about something like this:

template void foo(const GraphFrom& from,GraphTo& to) { typedef typename GraphFrom::vertex_iterator viter; typedef typename GraphFrom::vertex_descriptor vdesc; typedef typename GraphFrom::edge_iterator eiter; typedef std::map map_t;

map_t table;

viter vi,vend; //copy vertices for(tie(vi,vend)=from.vertices(); vi!=vend; ++vi) table[*vi] = add_vertex(to);

eiter ei,eend; //copy edges for(tie(ei,eend)=from.edges(); ei!=eend; ++ei) { vdesc s = source(*ei,from); vdesc t = target(*ei,from);

add_edge(table[s],table[t]); } }

Assuming my template mangling is correct, this should produce an isomorphic graph of the corresponding type in about O( VlgV + ElgE ) time.

Justin

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