[Nauty] generate all S-free graphs

[Brendan McKay]

* Sterten at aol.com <Sterten at aol.com> [021122 16:40]:
> Given a set S of graphs of small size,
> I want to generate efficiently all graphs of size n,
> which don't contain any of the graphs from S as induced subgraph.
> 
> I already have a subroutine, which checks whether
> G contains a graph from S.
> The property is hereditary : as soon as there is a forbidden
> subgraph we can immediately backtrack.
> 
> Can I modify geng.c easily or will it be difficult for me ?

geng.c has facilities for this exact application.  It is
explained in the comments at the start of the source code
(look for "PRUNE").  Basically, you write a procedure which
returns 1 if there is a forbidden subgraph and 0 if not.
This is best done in a separate file (don't modify geng.c).
Then compile geng.c with PRUNE defined as the same of your
procedure and of course link in your new file.  That's it.

Brendan.