[Scip] Branching using SCIP solely as a CP Solver

[Stefan Heinz]

Hi Alexander,

On 11/15/2011 10:30 AM, Alexander Schnell wrote:
> Hi all,
>
> i'm using SCIP solely as a CP Solver by setting the corresponding
> emphasis.
>
> The decision variables of my problem are integer.
>
> How could i add a branching rule
> which at first branches on the variable with the shortest
> lower bound and then starts by selecting the smallest value in the
> respective domain?
Such a branching rule does not exist in SCIP.
> Do i have to implement a branching rule myself or is this
> already included in SCIP?
Yes you have to implement that rule. This is, however, not so hard. Just 
follow the instruction:

http://scip.zib.de/doc/html/BRANCH.html

Basically, you only need to implement the method:

http://scip.zib.de/doc/html/BRANCH.html#BRANCHEXECPS

in case of a CP search.

To get the information you need you use the method 
SCIPgetPseudoBranchCands()

http://scip.zib.de/doc/html/scip_8h.html#acb6423287e73b4c01172b888b615d5d6

to get all integer which are not fixed yet. Using the function 
SCIPvarGetLbLocal() and SCIPvarGetUbLocal() you get access to the 
(local) variable bounds.

Best Stefan
> Best regards,
>
> Alexander Schnell
>
>
>
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