static
SCIP_Bool consdataCheck(
SCIP* scip, /**< SCIP data structure */
SCIP_PROBDATA* probdata, /**< problem data */
SCIP_CONSDATA* consdata /**< constraint data */
)
{
SCIP_VAR** vars;
int nvars;
SCIP_VARDATA* vardata;
SCIP_VAR* var;
int* consids;
int nconsids;
SCIP_Bool existid1;
SCIP_Bool existid2;
CONSTYPE type;
int pos;
int v;
vars = SCIPprobdataGetVars(probdata);
nvars = SCIPprobdataGetNVars(probdata);
for( v = 0; v < nvars; ++v )
{
var = vars[v];
/* if variables is locally fixed to zero continue */
if( SCIPvarGetLbLocal(var) < 0.5 )
continue;
/* check if the packing which corresponds to the variable is feasible for this constraint */
vardata = SCIPvarGetData(var);
nconsids = SCIPvardataGetNConsids(vardata);
consids = SCIPvardataGetConsids(vardata);
existid1 = SCIPsortedvecFindInt(consids, consdata->itemid1, nconsids, &pos);
existid2 = SCIPsortedvecFindInt(consids, consdata->itemid2, nconsids, &pos);
type = consdata->type;
if( (type == SAME && existid1 != existid2) || (type == DIFFER && existid1 && existid2) )
{
SCIPdebug( SCIPvardataPrint(scip, vardata, NULL) );
SCIPdebug( consdataPrint(scip, consdata, NULL) );
SCIPdebug( SCIPprintVar(scip, var, NULL) );
return FALSE;
}
}
return TRUE;
}
/** fixes a variable to zero if the corresponding packings are not valid for this constraint/node (due to branching) */
static
SCIP_RETCODE checkVariable(
SCIP* scip, /**< SCIP data structure */
SCIP_CONSDATA* consdata, /**< constraint data */
SCIP_VAR* var, /**< variables to check */
int* nfixedvars, /**< pointer to store the number of fixed variables */
SCIP_Bool* cutoff /**< pointer to store if a cutoff was detected */
)
{
SCIP_VARDATA* vardata;
int* consids;
int nconsids;
SCIP_Bool existid1;
SCIP_Bool existid2;
CONSTYPE type;
SCIP_Bool fixed;
SCIP_Bool infeasible;
int pos;
assert(scip != NULL);
assert(consdata != NULL);
assert(var != NULL);
assert(nfixedvars != NULL);
assert(cutoff != NULL);
/* if variables is locally fixed to zero continue */
if( SCIPvarGetUbLocal(var) < 0.5 )
return SCIP_OKAY;
/* check if the packing which corresponds to the variable feasible for this constraint */
vardata = SCIPvarGetData(var);
nconsids = SCIPvardataGetNConsids(vardata);
consids = SCIPvardataGetConsids(vardata);
existid1 = SCIPsortedvecFindInt(consids, consdata->itemid1, nconsids, &pos);
existid2 = SCIPsortedvecFindInt(consids, consdata->itemid2, nconsids, &pos);
type = consdata->type;
if( (type == SAME && existid1 != existid2) || (type == DIFFER && existid1 && existid2) )
{
SCIP_CALL( SCIPfixVar(scip, var, 0.0, &infeasible, &fixed) );
if( infeasible )
{
assert( SCIPvarGetLbLocal(var) > 0.5 );
SCIPdebugMessage("-> cutoff\n");
(*cutoff) = TRUE;
}
else
{
assert(fixed);
(*nfixedvars)++;
}
}
return SCIP_OKAY;
}
/** avoid to generate columns which are fixed to zero; therefore add for each variable which is fixed to zero a
* corresponding logicor constraint to forbid this column
*
* @note variable which are fixed locally to zero should not be generated again by the pricing MIP
*/
static
SCIP_RETCODE addFixedVarsConss(
SCIP* scip, /**< SCIP data structure */
SCIP* subscip, /**< pricing SCIP data structure */
SCIP_VAR** vars, /**< variable array of the subscuip */
SCIP_CONS** conss, /**< array of setppc constraint for each item one */
int nitems /**< number of items */
)
{
SCIP_VAR** origvars;
int norigvars;
SCIP_CONS* cons;
int* consids;
int nconsids;
int consid;
int nvars;
SCIP_VAR** logicorvars;
SCIP_VAR* var;
SCIP_VARDATA* vardata;
SCIP_Bool needed;
int nlogicorvars;
int v;
int c;
int o;
/* collect all variable which are currently existing */
origvars = SCIPgetVars(scip);
norigvars = SCIPgetNVars(scip);
/* loop over all these variables and check if they are fixed to zero */
for( v = 0; v < norigvars; ++v )
{
assert(SCIPvarGetType(origvars[v]) == SCIP_VARTYPE_BINARY);
/* if the upper bound is smaller than 0.5 if follows due to the integrality that the binary variable is fixed to zero */
if( SCIPvarGetUbLocal(origvars[v]) < 0.5 )
{
SCIPdebugMessage("variable <%s> glb=[%.15g,%.15g] loc=[%.15g,%.15g] is fixed to zero\n",
SCIPvarGetName(origvars[v]), SCIPvarGetLbGlobal(origvars[v]), SCIPvarGetUbGlobal(origvars[v]),
SCIPvarGetLbLocal(origvars[v]), SCIPvarGetUbLocal(origvars[v]) );
/* coolect the constraints/items the variable belongs to */
vardata = SCIPvarGetData(origvars[v]);
nconsids = SCIPvardataGetNConsids(vardata);
consids = SCIPvardataGetConsids(vardata);
needed = TRUE;
SCIP_CALL( SCIPallocBufferArray(subscip, &logicorvars, nitems) );
nlogicorvars = 0;
consid = consids[0];
nvars = 0;
/* loop over these items and create a linear (logicor) constraint which forbids this item combination in the
* pricing problem; thereby check if this item combination is already forbidden
*/
for( c = 0, o = 0; o < nitems && needed; ++o )
{
assert(o <= consid);
cons = conss[o];
if( SCIPconsIsEnabled(cons) )
{
assert( SCIPgetNFixedonesSetppc(scip, cons) == 0 );
var = vars[nvars];
nvars++;
assert(var != NULL);
if( o == consid )
{
SCIP_CALL( SCIPgetNegatedVar(subscip, var, &var) );
}
logicorvars[nlogicorvars] = var;
nlogicorvars++;
}
else if( o == consid )
needed = FALSE;
if( o == consid )
{
c++;
if ( c == nconsids )
consid = nitems + 100;
else
{
assert(consid < consids[c]);
consid = consids[c];
}
}
}
if( needed )
{
SCIP_CALL( SCIPcreateConsBasicLogicor(subscip, &cons, SCIPvarGetName(origvars[v]), nlogicorvars, logicorvars) );
SCIP_CALL( SCIPsetConsInitial(subscip, cons, FALSE) );
SCIP_CALL( SCIPaddCons(subscip, cons) );
SCIP_CALL( SCIPreleaseCons(subscip, &cons) );
}
SCIPfreeBufferArray(subscip, &logicorvars);
}
}
return SCIP_OKAY;
}
