Hello, I'm using Gecode to tackle a 2D packing subproblem inside an optimization problem. The subproblem is about packing rectangles (for the meantime without rotation) into a given larger rectangle and many instances of moderate size need to be solved. Fortunately I was able to start with the perfect-square example, where the adapted variant already performs quite good (using the cumulatives constraint). Also enabling branching on intervals yielded a speed-up. Now I was wondering if someone of you already implemented a suitable diffn constraint (see http://www.emn.fr/z-info/sdemasse/gccat/Cdiffn.html) in Gecode. In this way the non-overlapping part would (presumably) be tackled more efficiently and give an additional performance boost. Do you think having a look at the diff/diff2 implementation in JaCoP is useful for implementing it in Gecode? Thanks!
Best regards, Sandro _______________________________________________ Gecode users mailing list [email protected] https://www.gecode.org/mailman/listinfo/gecode-users
