/** initialization method of event handler (called after problem was transformed) */
static
SCIP_DECL_EVENTINIT(eventInitBoundwriting)
{ /*lint --e{715}*/
SCIP_EVENTHDLRDATA* eventhdlrdata;
assert(scip != NULL);
assert(eventhdlr != NULL);
assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
/* notify SCIP that your event handler wants to react on the event type best solution found */
SCIP_CALL( SCIPcatchEvent(scip, SCIP_EVENTTYPE_NODESOLVED, eventhdlr, NULL, NULL) );
eventhdlrdata = SCIPeventhdlrGetData(eventhdlr);
assert(eventhdlrdata != NULL);
eventhdlrdata->lastpb = SCIPinfinity(scip) * (SCIPgetObjsense(scip) == SCIP_OBJSENSE_MINIMIZE ? 1.0 : -1.0);
return SCIP_OKAY;
}
/** returns whether the debug solution is worse as the best known solution or if the debug solution was found */
static
SCIP_Bool debugSolIsAchieved(
SCIP_SET* set /**< global SCIP settings */
)
{
SCIP_SOL* bestsol;
SCIP* scip;
if( solisachieved )
return TRUE;
assert(set != NULL);
scip = set->scip;
assert(scip != NULL);
bestsol = SCIPgetBestSol(scip);
if( bestsol != NULL )
{
SCIP_Real solvalue;
/* don't check solution while in problem creation stage */
if( SCIPsetGetStage(set) == SCIP_STAGE_PROBLEM )
return TRUE;
solvalue = SCIPgetSolOrigObj(scip, bestsol);
/* make sure a debug solution has been read, so we do not compare against the initial debugsolval == 0 */
SCIP_CALL( readSolution(set) );
if( (SCIPgetObjsense(scip) == SCIP_OBJSENSE_MINIMIZE && SCIPsetIsLE(set, solvalue, debugsolval)) || (SCIPgetObjsense(scip) == SCIP_OBJSENSE_MAXIMIZE && SCIPsetIsGE(set, solvalue, debugsolval)) )
solisachieved = TRUE;
}
return solisachieved;
}
/** creates the objective value inequality and the objective value variable, if not yet existing */
static
SCIP_RETCODE createObjRow(
SCIP* scip, /**< SCIP data structure */
SCIP_SEPA* sepa, /**< separator */
SCIP_SEPADATA* sepadata /**< separator data */
)
{
assert(sepadata != NULL);
if( sepadata->objrow == NULL )
{
SCIP_VAR** vars;
SCIP_Real obj;
SCIP_Real intobjval;
int nvars;
int v;
SCIP_Bool attendobjvarbound;
attendobjvarbound = FALSE;
/* create and add objective value variable */
if( sepadata->objvar == NULL )
{
SCIP_CALL( SCIPcreateVar(scip, &sepadata->objvar, "objvar", -SCIPinfinity(scip), SCIPinfinity(scip), 0.0,
SCIP_VARTYPE_IMPLINT, FALSE, TRUE, NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, sepadata->objvar) );
SCIP_CALL( SCIPaddVarLocks(scip, sepadata->objvar, +1, +1) );
}
else
attendobjvarbound = TRUE;
/* get problem variables */
vars = SCIPgetOrigVars(scip);
nvars = SCIPgetNOrigVars(scip);
/* create objective value inequality */
if( SCIPgetObjsense(scip) == SCIP_OBJSENSE_MINIMIZE )
{
if( attendobjvarbound )
intobjval = SCIPceil(scip, SCIPgetDualbound(scip)) - SCIPvarGetLbGlobal(sepadata->objvar);
else
intobjval = SCIPceil(scip, SCIPgetDualbound(scip));
SCIP_CALL( SCIPcreateEmptyRowSepa(scip, &sepadata->objrow, sepa, "objrow", intobjval, SCIPinfinity(scip),
FALSE, !SCIPallVarsInProb(scip), TRUE) );
sepadata->setoff = intobjval;
}
else
{
if( attendobjvarbound )
intobjval = SCIPceil(scip, SCIPgetDualbound(scip)) - SCIPvarGetUbGlobal(sepadata->objvar);
else
intobjval = SCIPfloor(scip, SCIPgetDualbound(scip));
SCIP_CALL( SCIPcreateEmptyRowSepa(scip, &sepadata->objrow, sepa, "objrow", -SCIPinfinity(scip), intobjval,
FALSE, !SCIPallVarsInProb(scip), TRUE) );
sepadata->setoff = intobjval;
}
SCIP_CALL( SCIPcacheRowExtensions(scip, sepadata->objrow) );
for( v = 0; v < nvars; ++v )
{
obj = SCIPvarGetObj(vars[v]);
if( !SCIPisZero(scip, obj) )
{
SCIP_CALL( SCIPaddVarToRow(scip, sepadata->objrow, vars[v], obj) );
}
}
SCIP_CALL( SCIPaddVarToRow(scip, sepadata->objrow, sepadata->objvar, -1.0) );
SCIP_CALL( SCIPflushRowExtensions(scip, sepadata->objrow) );
SCIPdebugMessage("created objective value row: ");
SCIPdebug( SCIP_CALL( SCIPprintRow(scip, sepadata->objrow, NULL) ) );
}
return SCIP_OKAY;
}
/** searches and adds integral objective cuts that separate the given primal solution */
static
SCIP_RETCODE separateCuts(
SCIP* scip, /**< SCIP data structure */
SCIP_SEPA* sepa, /**< the intobj separator */
SCIP_SOL* sol, /**< the solution that should be separated, or NULL for LP solution */
SCIP_RESULT* result /**< pointer to store the result */
)
{
SCIP_SEPADATA* sepadata;
SCIP_Real objval;
SCIP_Real intbound;
SCIP_Bool infeasible;
SCIP_Bool tightened;
assert(result != NULL);
assert(*result == SCIP_DIDNOTRUN);
/* if the objective value may be fractional, we cannot do anything */
if( !SCIPisObjIntegral(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
/* if the current objective value is integral, there is no integral objective value cut */
if( sol == NULL )
objval = SCIPretransformObj(scip, SCIPgetLPObjval(scip));
else
objval = SCIPgetSolOrigObj(scip, sol);
if( SCIPisFeasIntegral(scip, objval) )
return SCIP_OKAY;
sepadata = SCIPsepaGetData(sepa);
assert(sepadata != NULL);
/* the objective value is fractional: create the objective value inequality, if not yet existing */
SCIP_CALL( createObjRow(scip, sepa, sepadata) );
/* adjust the bounds of the objective value variable */
if( SCIPgetObjsense(scip) == SCIP_OBJSENSE_MINIMIZE )
{
intbound = SCIPceil(scip, objval) - sepadata->setoff;
SCIP_CALL( SCIPtightenVarLb(scip, sepadata->objvar, intbound, FALSE, &infeasible, &tightened) );
SCIPdebugMessage("new objective variable lower bound: <%s>[%g,%g]\n",
SCIPvarGetName(sepadata->objvar), SCIPvarGetLbLocal(sepadata->objvar), SCIPvarGetUbLocal(sepadata->objvar));
}
else
{
intbound = SCIPfloor(scip, objval) - sepadata->setoff;
SCIP_CALL( SCIPtightenVarUb(scip, sepadata->objvar, intbound, FALSE, &infeasible, &tightened) );
SCIPdebugMessage("new objective variable upper bound: <%s>[%g,%g]\n",
SCIPvarGetName(sepadata->objvar), SCIPvarGetLbLocal(sepadata->objvar), SCIPvarGetUbLocal(sepadata->objvar));
}
/* add the objective value inequality as a cut to the LP */
if( infeasible )
*result = SCIP_CUTOFF;
else
{
if( !SCIProwIsInLP(sepadata->objrow) )
{
SCIP_CALL( SCIPaddCut(scip, sol, sepadata->objrow, FALSE, &infeasible) );
}
if ( infeasible )
*result = SCIP_CUTOFF;
else if ( tightened )
*result = SCIP_REDUCEDDOM;
else
*result = SCIP_SEPARATED;
}
return SCIP_OKAY;
}
