Thanks for your answer ! nevertheless I wonder why the webpage http://www.gecode.org/gecodej/ indicates that Gecode/J allows to implement search engines using copying and recomputation.
Don't you think I could program a new search engine totally in java as it's done for Gist ? cheers, Mikael On Mon, 2006-12-04 at 09:07 +0100, Guido Tack wrote: > Hi. > > > I'm using gecode/J 1.0.1-1 and wonder what's the best way to save the > > position in the search tree in a file in order to be able to > > compute the > > next solution later. Here's some details about what I want to do: > > > > * launch my program the first time : > > - find the first solution of a CSP > > - save the way to this solution in the search tree in a file > > - quit > > > > * relaunch my program with arguments to indicate I want the next > > solution : > > - load the state (go to the node) > > - find the next solution > > - save the state (way to this solution) > > - quit > > > > > > I haven't found how to do that in the documentation... > > This is not possible with the search engines we provide, but quite > easy to implement yourself. One slight complication is that you use > Gecode/J. In Java, we just use an interface to the C++ search > engines, so you don't have a Java implementation to start with. > > If you know some C++, I would suggest you have a look at how search > is implemented there. The most interesting files are gecode/search/ > reco-stack.icc and gecode/search/dfs.icc. Basically, you have a stack > that stores branching descriptions and (in some stack cells) copies > of spaces. To save the state, you will just have to traverse the > stack and save the number of the alternative that has to be explored > next from each stack cell. To load the state, recreate the original > problem, and then recreate the stack by recomputation. Note, however, > that you cannot save the branching descriptions (they are completely > abstract anyway), just save the number of the alternative at each point. > > I hope this helps getting you started. If anything is not clear to > you, just ask. > > Cheers, > Guido > > > _______________________________________________ > Gecode users mailing list > [EMAIL PROTECTED] > https://www.gecode.org/mailman/listinfo/gecode-users _______________________________________________ Gecode users mailing list [EMAIL PROTECTED] https://www.gecode.org/mailman/listinfo/gecode-users
