[SCIP] Problems with branch-and-price

[Veronica Dal Sasso]

Dear all,
I'm implementing a branch-and-price algorithm using C++ and SCIP, and I am
facing a couple of difficulties:

1) most of the times, when I need to use Farkas pricing, my program stops
and waits for some input, printing on the screen the string "<press>". I
just give a letter as input and then it goes on with the computation, but I
don't understand why it happens and how I can avoid it (and if it affects
in any way the results).

2) I implemented a branching rule following the binpacking example, but I
don't understand the role played by the function

addFixedVarsConss(SCIP* scip, SCIP* subscip, SCIP_VAR** vars, SCIP_CONS**
conss, int nitems)

in file pricer_binpacking.c, as at each node I already fix to 0 the
forbidden variables with the functions

checkVariable(SCIP* scip, SCIP_CONSDATA* consdata, SCIP_VAR* var, int
nfixedvars, SCIP_Bool cutoff)

and

consdataFixVariables((SCIP* scip, SCIP_CONSDATA* consdata, SCIP_VAR** vars,
int nvars, SCIP_RESULT* result)

in file cons_samediff.c and then my pricing problem is modified as to
include informations on the forbidden columns, so that they will not be
generated at that node and chid nodes.
So as far as now I didn't implement the function addFixedVarsConss() but,
as I get a wrong solution to my problem, I'm thinking that maybe it has a
different role and that I need to implement it. Is that correct?

Thank you very much for your help,

Veronica Dal Sasso
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