I'm optimizing my constraints with Gist at the moment.
I've found that there are lots of pruned tree on the left hand side.
These trees may span up to 4-5 levels.
Unfortunately, when I trigger gist to print out the dead node, I didn't find
any values that is making any constraints failed. I had tried to add implied
constraints which had already improve the speed for some cases.
I'm currently using: INT_VAR_SIZE_MAX, INT_VAL_MIN for branching an
IntVarArray.
(1) What problems may it be? Is there any dynamic implied constraint in Gist?
(2) If I found that many dead node of a big pruned tree is found by the last
assignment of values, How can I make such assignment comes earlier? e.g. Assign
variables with more constraints first? Is it possible for Gist?
(3) Do you mind if I send up my little program for you to understand more about
the Gist tree span?
(4) Although i use "INT_VAR_SIZE_MAX", it doesn't assign all values at once. Is
that a bug or i'm misunderstanding its use? "INT_VAR_RND" is not suitable to me
cause I want the search to be deterministic.
(5) Is there any other tricks I could use to sort out the problem? e.g.
Deleting the constraint one by one to see which constraint is making it goes so
long?
(6) Is there another symthoms i should try to look at the gist tree to get hint
about the problem? e.g. what propagation setting should it be.
Big thanks again.
Yahoo!香港提供網上安全攻略，教你如何防範黑客! 請前往 http://hk.promo.yahoo.com/security/ 了解更多!_______________________________________________
Gecode users mailing list
[email protected]
https://www.gecode.org/mailman/listinfo/gecode-users
