cons_cumulative.c
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33 * - a set of jobs, represented by their integer start time variables \f$S_j\f$, their array of processing times \f$p_j\f$ and of
37 * The cumulative constraint ensures that for each point in time \f$t\f$ \f$\sum_{j: S_j \leq t < S_j + p_j} d_j \leq C\f$ holds.
51/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
71#define CONSHDLR_ENFOPRIORITY -2040000 /**< priority of the constraint handler for constraint enforcing */
72#define CONSHDLR_CHECKPRIORITY -3030000 /**< priority of the constraint handler for checking feasibility */
73#define CONSHDLR_SEPAFREQ 1 /**< frequency for separating cuts; zero means to separate only in the root node */
74#define CONSHDLR_PROPFREQ 1 /**< frequency for propagating domains; zero means only preprocessing propagation */
75#define CONSHDLR_EAGERFREQ 100 /**< frequency for using all instead of only the useful constraints in separation,
77#define CONSHDLR_MAXPREROUNDS -1 /**< maximal number of presolving rounds the constraint handler participates in (-1: no limit) */
78#define CONSHDLR_DELAYSEPA FALSE /**< should separation method be delayed, if other separators found cuts? */
79#define CONSHDLR_DELAYPROP FALSE /**< should propagation method be delayed, if other propagators found reductions? */
80#define CONSHDLR_NEEDSCONS TRUE /**< should the constraint handler be skipped, if no constraints are available? */
102#define DEFAULT_TTINFER TRUE /**< should time-table (core-times) propagator be used to infer bounds? */
105#define DEFAULT_USEADJUSTEDJOBS FALSE /**< should during edge-finding jobs be adusted which run on the border of the effective time horizon? */
106#define DEFAULT_TTEFCHECK TRUE /**< should time-table edge-finding be used to detect an overload? */
113#define DEFAULT_PRESOLPAIRWISE TRUE /**< should pairwise constraint comparison be performed in presolving? */
115#define DEFAULT_DETECTDISJUNCTIVE TRUE /**< search for conflict set via maximal cliques to detect disjunctive constraints */
116#define DEFAULT_DETECTVARBOUNDS TRUE /**< search for conflict set via maximal cliques to detect variable bound constraints */
117#define DEFAULT_MAXNODES 10000LL /**< number of branch-and-bound nodes to solve an independent cumulative constraint (-1: no limit) */
123#define DEFAULT_USEBDWIDENING TRUE /**< should bound widening be used during conflict analysis? */
178 unsigned int varbounds:1; /**< bool to store if variable bound strengthening was already preformed */
179 unsigned int triedsolving:1; /**< bool to store if we tried already to solve that constraint as independent subproblem */
192 SCIP_Bool cutsasconss; /**< should the cumulative constraint create cuts as knapsack constraints? */
196 SCIP_Bool useadjustedjobs; /**< should during edge-finding jobs be adusted which run on the border of the effective time horizon? */
209 SCIP_Bool detectdisjunctive; /**< search for conflict set via maximal cliques to detect disjunctive constraints */
210 SCIP_Bool detectvarbounds; /**< search for conflict set via maximal cliques to detect variable bound constraints */
212 SCIP_Bool presolpairwise; /**< should pairwise constraint comparison be performed in presolving? */
215 SCIP_Longint maxnodes; /**< number of branch-and-bound nodes to solve an independent cumulative constraint (-1: no limit) */
217 SCIP_DECL_SOLVECUMULATIVE((*solveCumulative)); /**< method to use a single cumulative condition */
221 SCIP_Longint nlbtimetable; /**< number of times the lower bound was tightened by the time-table propagator */
222 SCIP_Longint nubtimetable; /**< number of times the upper bound was tightened by the time-table propagator */
223 SCIP_Longint ncutofftimetable; /**< number of times the a cutoff was detected due to time-table propagator */
224 SCIP_Longint nlbedgefinder; /**< number of times the lower bound was tightened by the edge-finder propagator */
225 SCIP_Longint nubedgefinder; /**< number of times the upper bound was tightened by the edge-finder propagator */
226 SCIP_Longint ncutoffedgefinder; /**< number of times the a cutoff was detected due to edge-finder propagator */
227 SCIP_Longint ncutoffoverload; /**< number of times the a cutoff was detected due to overload checking via edge-finding */
228 SCIP_Longint nlbTTEF; /**< number of times the lower bound was tightened by time-table edge-finding */
229 SCIP_Longint nubTTEF; /**< number of times the upper bound was tightened by time-table edge-finding */
230 SCIP_Longint ncutoffoverloadTTEF;/**< number of times the a cutoff was detected due to overload checking via time-table edge-finding */
232 int nirrelevantjobs; /**< number of time a irrelevant/redundant jobs was removed form a constraint */
233 int nalwaysruns; /**< number of time a job removed form a constraint which run completely during the effective horizon */
237 int ndualbranchs; /**< number of times a dual branch was discoverd and applicable via probing */
238 int nallconsdualfixs; /**< number of times a dual fix was performed due to knowledge of all cumulative constraints */
248 * An inference information can be passed with each domain reduction to SCIP. This information is passed back to the
249 * constraint handler if the corresponding bound change has to be explained. It can be used to store information which
250 * help to construct a reason/explanation for a bound change. The inference information is limited to size of integer.
252 * In case of the cumulative constraint handler we store the used propagation algorithms for that particular bound
265};
344/** constructs an inference information out of a propagation rule, an earliest start and a latest completion time */
355 if( proprule == PROPRULE_0_INVALID || data1 < 0 || data1 >= (1<<15) || data2 < 0 || data2 >= (1<<15) )
401#define computeCoreWithInterval(begin, end, ect, lst) (MAX(0, MIN((end), (ect)) - MAX((lst), (begin))))
426 /* the code contains a bug; we need to check if an implication forces that the jobs do not run in parallel */
494 /* the code contains a bug; we need to check if an implication forces that the jobs do not run in parallel */
536/** collects all necessary binary variables to represent the jobs which can be active at time point of interest */
581 /* check the end time of this job is larger than the curtime; in this case the job is still running */
690 /* check the end time of this job is larger than the curtime; in this case the job is still running */
750 /* sort the arrays not-decreasing according to startsolvalues and endsolvalues (and sort the indices in the same way) */
789 /* sort the arrays not-decreasing according to startsolvalues and endsolvalues (and sort the indices in the same way) */
839 SCIPdebugMsg(scip, "%d: variable <%s>[%g,%g] (sol %g, duration %d) starttime %d, endtime = %d, demand = %d\n",
840 *nvars, SCIPvarGetName(var), SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var), SCIPgetSolVal(scip, sol, var),
859 SCIPdebugMsg(scip, "%d: variable <%s>[%g,%g] (sol %g, duration %d) starttime %d, endtime = %d, demand = %d\n",
860 *nvars, SCIPvarGetName(var), SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var), SCIPgetSolVal(scip, sol, var),
869 /* sort the arrays not-decreasing according to startsolvalues and endsolvalues (and sort the indices in the same way) */
904 SCIP_Real** cumulativedemands, /**< array to store the estimated cumulative demand for each point in time */
912 int* startindices; /* we will sort the startsolvalues, thus we need to know wich index of a job it corresponds to */
913 int* endindices; /* we will sort the endsolvalues, thus we need to know wich index of a job it corresponds to */
938 createSortedEventpoints(scip, nvars, vars, durations, starttimes, endtimes, startindices, endindices, TRUE);
1124 disjfactor2 = MAX( disjfactor2, (peak-(SCIP_Real)capacity)/peak * (nlarge/(SCIP_Real)ndemands) );
1125 cumfactor1 = MAX( cumfactor1, (peak-capacity)/peak * (capacity-deltademand)/(SCIP_Real)capacity );
1164 SCIPstatisticPrintf("cumulative constraint<%s>: DISJ1=%g, DISJ2=%g, CUM=%g, RS1 = %g, RS2 = %g, EST = %g\n",
1165 SCIPconsGetName(cons), consdata->disjfactor1, disjfactor2, cumfactor1, resstrength1, resstrength2,
1247 SCIP_Real* objvals, /**< array of objective coefficients for each job (linear objective function), or NULL if none */
1295 SCIP_CALL( SCIPcreateVarBasic(subscip, &subvars[v], name, ests[v], lsts[v], objval, SCIP_VARTYPE_INTEGER) );
1313 * @note This "meta" setting has to be set first since this call overwrite all parameters including for example the
1339 SCIPdebugMsg(subscip, "solved single cumulative condition with status %d\n", SCIPgetStatus(subscip));
1482 /* create for each job and time step a binary variable which is one if this jobs starts at this time point and a set
1523 SCIP_CALL( SCIPcreateVarBasic(subscip, &binvar, name, 0.0, 1.0, objval, SCIP_VARTYPE_BINARY) );
1526 /* add binary varibale to the set partitioning constraint which ensures that the job is started */
1537 /* adjusted the smallest earliest start time and the largest latest completion time with the effective horizon */
1544 /* create for each time a knapsack constraint which ensures that the resource capacity is not exceeded */
1553 SCIP_CALL( SCIPcreateConsBasicKnapsack(subscip, &cons, name, 0, NULL, NULL, (SCIP_Longint)capacity) );
1614 SCIPdebugMsg(scip, "solved single cumulative condition with status %d\n", SCIPgetStatus(subscip));
1680 /* check which binary varibale is the first binary varibale which is not globally fixed to zero */
1690 /* check which binary varibale is the last binary varibale which is not globally fixed to zero */
1745 * Method used to create and free the constraint handler data when including and removing the cumulative constraint
1910 SCIP_CONS** linkingconss, /**< array of linking constraints for the integer variables, or NULL */
1969 /* initialize variable lock data structure; the locks are only used if the constraint is a check constraint */
1974 SCIP_CALL( SCIPduplicateBlockMemoryArray(scip, &(*consdata)->linkingconss, linkingconss, nvars) );
1983 SCIP_CALL( SCIPgetTransformedVars(scip, (*consdata)->nvars, (*consdata)->vars, (*consdata)->vars) );
1985 /* multi-aggregated variables cannot be replaced by active variable; therefore we mark all variables for not
1996 SCIP_CALL( SCIPtransformConss(scip, (*consdata)->nvars, (*consdata)->linkingconss, (*consdata)->linkingconss) );
2158 SCIPinfoMessage(scip, file, ")[%d,%d) <= %d", consdata->hmin, consdata->hmax, consdata->capacity);
2183 SCIP_CALL( SCIPunlockVarCons(scip, consdata->vars[pos], cons, consdata->downlocks[pos], consdata->uplocks[pos]) );
2204 SCIPvarGetName(consdata->vars[pos]), SCIPvarGetLbGlobal(consdata->vars[pos]), SCIPvarGetUbGlobal(consdata->vars[pos]), SCIPconsGetName(cons));
2206 /* in case the we did not remove the variable in the last slot of the arrays we move the current last to this
2257 SCIPdebugMsg(scip, "linking constraint (%d of %d) for variable <%s>\n", v+1, nvars, SCIPvarGetName(var));
2280 assert(strcmp(SCIPconshdlrGetName(SCIPconsGetHdlr(consdata->linkingconss[v])), "linking") == 0 );
2295/** check for the given starting time variables with their demands and durations if the cumulative conditions for the
2303 SCIP_VAR** vars, /**< array of integer variable which corresponds to starting times for a job */
2316 int* startindices; /* we will sort the startsolvalues, thus we need to know which index of a job it corresponds to */
2317 int* endindices; /* we will sort the endsolvalues, thus we need to know which index of a job it corresponds to */
2339 /* compute time points where we have to check whether capacity constraint is infeasible or not */
2350 /* the constraint of the cumulative constraint handler should be called after the integrality check */
2355 /* we need to ensure that we check at least one time point during the effective horizon; therefore we project all
2365 /* sort the arrays not-decreasing according to start solution values and end solution values (and sort the
2453/** check if the given constrait is valid; checks each starting point of a job whether the remaining capacity is at
2506 SCIP_BDCHGIDX* bdchgidx, /**< the index of the bound change, representing the point of time where the change took place */
2509 SCIP_Bool* explanation /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
2523 SCIPdebugMsg(scip, "variable <%s>: (demand %d) resolve propagation of core time algorithm (peak %d)\n",
2535 /* first we loop over all variables and adjust the capacity with those jobs which provide a global core at the
2536 * inference peak and those where the current conflict bounds provide a core at the inference peak
2550 /* compute cores of jobs; if core overlaps interval of inference variable add this job to the array */
2551 assert(!SCIPvarIsActive(var) || SCIPisFeasEQ(scip, SCIPgetVarUbAtIndex(scip, var, bdchgidx, TRUE), SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE)));
2553 assert(!SCIPvarIsActive(var) || SCIPisFeasEQ(scip, SCIPgetVarLbAtIndex(scip, var, bdchgidx, TRUE), SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE)));
2563 /* check if the inference peak is part of the global bound core; if so we decreasing the capacity by the demand of
2581 /* collect the conflict bound core (the conflict bounds are those bounds which are already part of the conflict)
2582 * hence these bound are already reported by other resolve propation steps. In case a bound (lower or upper) is
2588 /* check if the inference peak is part of the conflict bound core; if so we decreasing the capacity by the demand
2591 * @note we do not need to reported that job to SCIP since the required bounds are already reported
2618 /* collect all cores of the variables which lay in the considered time window except the inference variable */
2631 /* compute cores of jobs; if core overlaps interval of inference variable add this job to the array */
2632 assert(!SCIPvarIsActive(var) || SCIPisFeasEQ(scip, SCIPgetVarUbAtIndex(scip, var, bdchgidx, TRUE), SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE)));
2634 assert(!SCIPvarIsActive(var) || SCIPisFeasEQ(scip, SCIPgetVarLbAtIndex(scip, var, bdchgidx, TRUE), SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE)));
2642 SCIPvarGetName(var), SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE), SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE),
2686 SCIPdebugMsg(scip, "infer peak %d, relaxed peak %d, lst %d, ect %d\n", inferpeak, relaxedpeak, maxlst, minect);
2714 SCIP_CALL( SCIPaddConflictRelaxedLb(scip, var, bdchgidx, (SCIP_Real)(inferpeak - duration + 1)) );
2740/** repropagation of edge finding algorithm simplified version from Petr Vilim only a small subset is reported such that
2754 SCIP_BDCHGIDX* bdchgidx, /**< the index of the bound change, representing the point of time where the change took place */
2756 SCIP_Bool* explanation /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
2769 SCIPdebugMsg(scip, "repropagate edge-finding with short reasons for variable <%s>\n", SCIPvarGetName(infervar));
2811 /* in case the earliest start time is equal to hmin we have to also consider the jobs which run in that region
2816 /* in case the latest completion time is equal to hmax we have to also consider the jobs which run in that region
2845/** compute the minimum overlaps w.r.t. the duration of the job and the time window [begin,end) */
2878/** an overload was detected due to the time-time edge-finding propagate; initialized conflict analysis, add an initial
2881 * @note the conflict analysis is not performend, only the initialized SCIP_Bool pointer is set to TRUE
2895 SCIP_BDCHGIDX* bdchgidx, /**< the index of the bound change, representing the point of time where the change took place */
2898 SCIP_Bool* explanation /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
2915 SCIPdebugMsg(scip, "analysis energy load in [%d,%d) (capacity %d, energy %" SCIP_LONGINT_FORMAT ")\n", begin, end, capacity, requiredenergy);
2917 /* collect global contribution and adjusted the required energy by the amount of energy the inference variable
2952 SCIPvarGetName(var), SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE), SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE),
2955 /* compute the amount of energy which needs to be available for enforcing the propagation and report the bound
2962 /* get the latest start time of the infer start time variable before the propagation took place */
2965 /* the latest start time of the inference start time variable before the propagation needs to be smaller as
2966 * the end of the time interval; meaning the job needs be overlap with the time interval in case the job is
2971 /* compute the overlap of the job in case it would be scheduled w.r.t. its latest start time and the time
2976 /* the job needs to overlap with the interval; otherwise the propagation w.r.t. this time window is not valid */
2981 assert(bdchgidx == NULL || SCIPconvertRealToInt(scip, SCIPgetVarUbAtIndex(scip, var, bdchgidx, TRUE)) < begin);
2995 assert(SCIPconvertRealToInt(scip, SCIPgetVarUbAtIndex(scip, var, bdchgidx, FALSE)) <= (end - overlap));
3009 /* get the earliest completion time of the infer start time variable before the propagation took place */
3012 /* the earliest start time of the inference start time variable before the propagation needs to be larger as
3013 * than the beginning of the time interval; meaning the job needs be overlap with the time interval in case
3018 /* compute the overlap of the job in case it would be scheduled w.r.t. its earliest start time and the time
3023 /* the job needs to overlap with the interval; otherwise the propagation w.r.t. this time window is not valid */
3042 assert(SCIPconvertRealToInt(scip, SCIPgetVarLbAtIndex(scip, var, bdchgidx, FALSE)) >= (begin + overlap - duration));
3043 SCIP_CALL( SCIPaddConflictRelaxedLb(scip, var, bdchgidx, (SCIP_Real)(begin + overlap - duration)) );
3051 /* subtract the amount of energy which is available due to the overlap of the inference start time */
3066 /* check if the has any overlap w.r.t. global bound; meaning some parts of the job will run for sure within the
3085 /* check if the job has any overlap w.r.t. local bound; meaning some parts of the job will run for sure within the
3146 SCIPdebugMsg(scip, "variable <%s> glb=[%g,%g] loc=[%g,%g], conf=[%g,%g], added=[%d,%d] (demand %d, duration %d)\n",
3183 SCIP_BDCHGIDX* bdchgidx, /**< the index of the bound change, representing the point of time where the change took place */
3186 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
3187 SCIP_RESULT* result /**< pointer to store the result of the propagation conflict resolving call */
3217 /* we propagated the latest start time (upper bound) step wise with a step length of at most the duration of
3220 assert(SCIPgetVarUbAtIndex(scip, infervar, bdchgidx, FALSE) - SCIPgetVarUbAtIndex(scip, infervar, bdchgidx, TRUE) < inferduration + 0.5);
3228 /* the bound passed back to be resolved might be tighter as the bound propagted by the core time propagator;
3229 * this can happen if the variable is not activ and aggregated to an activ variable with a scale != 1.0
3231 assert(SCIPconvertRealToInt(scip, SCIPgetVarUbAtIndex(scip, infervar, bdchgidx, TRUE)) + inferduration <= inferpeak);
3255 /* the bound passed back to be resolved might be tighter as the bound propagted by the core time propagator;
3256 * this can happen if the variable is not activ and aggregated to an activ variable with a scale != 1.0
3258 assert(SCIPconvertRealToInt(scip, SCIPgetVarLbAtIndex(scip, infervar, bdchgidx, TRUE)) - 1 >= inferpeak);
3273 SCIP_CALL( resolvePropagationCoretimes(scip, nvars, vars, durations, demands, capacity, hmin, hmax,
3274 infervar, inferdemand, inferpeak, relaxedpeak, bdchgidx, usebdwidening, &provedpeak, explanation) );
3294 SCIP_CALL( SCIPaddConflictRelaxedLb(scip, infervar, bdchgidx, (SCIP_Real)(provedpeak - inferduration + 1)) );
3372 if( SCIPvarGetNLocksDownType(var, SCIP_LOCKTYPE_MODEL) == downlocks[v] && !SCIPisNegative(scip, objval) )
3380 SCIP_CALL( SCIPbranchVarHole(scip, var, SCIPvarGetLbLocal(var), (SCIP_Real)alternativelbs[v], NULL, NULL) );
3390 if( SCIPvarGetNLocksUpType(var, SCIP_LOCKTYPE_MODEL) == uplocks[v] && !SCIPisPositive(scip, objval) )
3398 SCIP_CALL( SCIPbranchVarHole(scip, var, (SCIP_Real)alternativeubs[v], SCIPvarGetUbLocal(var), NULL, NULL) );
3483/** computes a point in time when the capacity is exceeded returns hmax if this does not happen */
3494 int* startindices; /* we will sort the startsolvalues, thus we need to know wich index of a job it corresponds to */
3495 int* endindices; /* we will sort the endsolvalues, thus we need to know wich index of a job it corresponds to */
3540 subtractStartingJobDemands(consdata, curtime, starttimes, startindices, &freecapacity, &j, nvars);
3568/** checks all cumulative constraints for infeasibility and add branching candidates to storage */
3745/** in case the cumulative constraint is independent of every else, solve the cumulative problem and apply the fixings
3752 SCIP_Longint maxnodes, /**< number of branch-and-bound nodes to solve an independent cumulative constraint (-1: no limit) */
3778 /* if SCIP is in probing mode or repropagation we cannot perform this dual reductions since this dual reduction
3784 /* constraints for which the check flag is set to FALSE, did not contribute to the lock numbers; therefore, we cannot
3792 /* if the cumulative constraint is the only constraint of the original problem or the only check constraint in the
3806 /* after 250 conflict we force a restart since then the variable statistics are reasonable initialized */
3842 /* check if already tried to solve that constraint as independent sub problem; we do not want to try it again if we
3852 /* mark the constraint to be tried of solving it as independent sub problem; in case that is successful the
3857 SCIPdebugMsg(scip, "the cumulative constraint <%s> is independent from rest of the problem (%d variables, %d constraints)\n",
3872 /* if a variables array is given, use the variable bounds otherwise the default values stored in the ests and lsts
3890 /* substract the memory already used by the main SCIP and the estimated memory usage of external software */
3898 SCIP_CALL( SCIPsolveCumulative(scip, nvars, lbs, ubs, objvals, consdata->durations, consdata->demands, consdata->capacity,
3899 consdata->hmin, consdata->hmax, timelimit, memorylimit, maxnodes, &solved, cutoff, unbounded, &error) );
3979 SCIP_Bool* explanation /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
3982 SCIPdebugMsg(scip, "detected infeasibility due to adding a core to the core resource profile\n");
3983 SCIPdebugMsg(scip, "variable <%s>[%g,%g] (demand %d, duration %d)\n", SCIPvarGetName(infervar),
3991 SCIP_CALL( resolvePropagationCoretimes(scip, nvars, vars, durations, demands, capacity, hmin, hmax,
3996 /* add both bound of the inference variable since these biuld the core which we could not inserted */
3999 SCIP_CALL( SCIPaddConflictRelaxedLb(scip, infervar, NULL, (SCIP_Real)(inferpeak - inferduration + 1)) );
4014/** We are using the core resource profile which contains all core except the one of the start time variable which we
4015 * want to propagate, to incease the earliest start time. This we are doing in steps of length at most the duration of
4016 * the job. The reason for that is, that this makes it later easier to resolve this propagation during the conflict
4035 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
4062 /* first we find left position of earliest start time (lower bound) in resource profile; this position gives us the
4088 /* we search for a peak within the core profile which conflicts with the demand of the start time variable; we
4101 /* if we found no peak that means current the job could be scheduled at its earliest start time without
4108 /* the peak position gives us a time point where the start time variable is in conflict with the resource
4109 * profile. That means we have to move it to the next time point in the resource profile but at most to the
4121 SCIP_CALL( analyseInfeasibelCoreInsertion(scip, nvars, vars, durations, demands, capacity, hmin, hmax,
4132 /* construct the inference information which we are using with the conflict analysis to resolve that particular
4140 SCIP_CALL( SCIPinferVarLbCons(scip, var, (SCIP_Real)newlb, cons, inferInfoToInt(inferinfo), TRUE, infeasible, &tightened) );
4149 SCIPdebugMsg(scip, "variable <%s> new lower bound <%d> -> <%d>\n", SCIPvarGetName(var), est, newlb);
4152 /* for the statistic we count the number of times a lower bound was tightened due the the time-table algorithm */
4157 * @note We are taking the lower of the start time variable on purpose instead of newlb. This is due the fact that
4158 * the proposed lower bound might be even strength by be the core which can be the case if aggregations are
4175/** We are using the core resource profile which contains all core except the one of the start time variable which we
4176 * want to propagate, to decrease the latest start time. This we are doing in steps of length at most the duration of
4177 * the job. The reason for that is, that this makes it later easier to resolve this propagation during the conflict
4216 /* first we find left position of latest completion time minus 1 (upper bound + duration) in resource profile; That
4217 * is the last time point where the job would run if schedule it at its latest start time (upper bound). This
4247 /* we search for a peak within the core profile which conflicts with the demand of the start time variable; we
4259 /* if we found no peak that means the current job could be scheduled at its latest start time without conflicting
4266 /* the peak position gives us a time point where the start time variable is in conflict with the resource
4267 * profile. That means the job has be done until that point. Hence that gives us the latest completion
4268 * time. Note that that we want to move the bound by at most the duration length (the remaining move we are
4275 /* construct the inference information which we are using with the conflict analysis to resolve that particular
4283 SCIP_CALL( SCIPinferVarUbCons(scip, var, (SCIP_Real)newub, cons, inferInfoToInt(inferinfo), TRUE, &infeasible, &tightened) );
4292 SCIPdebugMsg(scip, "variable <%s>: new upper bound <%d> -> <%d>\n", SCIPvarGetName(var), lst, newub);
4295 /* for the statistic we count the number of times a upper bound was tightened due the the time-table algorithm */
4300 * @note We are taking the upper of the start time variable on purpose instead of newub. This is due the fact that
4301 * the proposed upper bound might be even strength by be the core which can be the case if aggregations are
4319/** compute for the different earliest start and latest completion time the core energy of the corresponding time
4328 int* coreEnergyAfterEst, /**< array to store the core energy after the earliest start time of each job */
4329 int* coreEnergyAfterLct /**< array to store the core energy after the latest completion time of each job */
4348 energy += SCIPprofileGetLoad(profile, t-1) * (SCIPprofileGetTime(profile, t) - SCIPprofileGetTime(profile, t-1));
4357 coreEnergyAfterEst[v] = energy + SCIPprofileGetLoad(profile, t-1) * (SCIPprofileGetTime(profile, t) - ests[v]);
4373 energy += SCIPprofileGetLoad(profile, t-1) * (SCIPprofileGetTime(profile, t) - SCIPprofileGetTime(profile, t-1));
4382 coreEnergyAfterLct[v] = energy + SCIPprofileGetLoad(profile, t-1) * (SCIPprofileGetTime(profile, t) - lcts[v]);
4477 SCIP_Longint energy, /**< available energy for the flexible part of the hob within the time window */
4479 int* inferinfos, /**< pointer to store the inference information which is need for the (best) lower bound change */
4481 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
4494 /* if the job can be processed completely before or after the time window, nothing can be tightened */
4498 /* if flexible part runs completely within the time window (assuming it is scheduled on its earliest start time), we
4504 /* check if the available energy in the time window is to small to handle the flexible part if it is schedule on its
4510 /* adjust the available energy for the job; the given available energy assumes that the core of the considered job is
4513 * @note the variable ect define the earliest completion time of the flexible part of the job; hence we need to
4518 /* compute a latest start time (upper bound) such that the job consums at most the available energy
4524 /* check if we detected an infeasibility which is the case if the new lower bound is larger than the current upper
4547 begin, end, var, SCIP_BOUNDTYPE_LOWER, NULL, relaxedbd, conshdlrdata->usebdwidening, explanation) );
4590 SCIP_Longint energy, /**< available energy for the flexible part of the hob within the time window */
4592 int* inferinfos, /**< pointer to store the inference information which is need for the (best) upper bound change */
4594 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
4608 /* if flexible part of the job can be processed completely before or after the time window, nothing can be tightened */
4612 /* if flexible part runs completely within the time window (assuming it is scheduled on its latest start time), we
4618 /* check if the available energy in the time window is to small to handle the flexible part of the job */
4622 /* adjust the available energy for the job; the given available energy assumes that the core of the considered job is
4625 * @note the variable lst define the latest start time of the flexible part of the job; hence we need to compute the
4631 /* compute a latest start time (upper bound) such that the job consums at most the available energy
4638 /* check if we detected an infeasibility which is the case if the new upper bound is smaller than the current lower
4661 begin, end, var, SCIP_BOUNDTYPE_UPPER, NULL, relaxedbd, conshdlrdata->usebdwidening, explanation) );
4684/** propagate the upper bounds and "opportunistically" the lower bounds using the time-table edge-finding algorithm */
4698 int* lbinferinfos, /**< array to store the inference information for the lower bound changes */
4699 int* ubinferinfos, /**< array to store the inference information for the upper bound changes */
4700 int* lsts, /**< array of latest start time of the flexible part in the same order as the variables */
4702 int* perm, /**< permutation of the variables w.r.t. the non-decreasing order of the earliest start times */
4708 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
4747 /* check if the smallest interval has a size such that the total energy fits, if so we can skip the propagator */
4753 /* loop over all variable in non-increasing order w.r.t. the latest completion time; thereby, the latest completion
4766 /* if the latest completion time is larger then hmax an infeasibility cannot be detected, since after hmax an
4779 /* if the latest completion time equals to previous end time, we can continue since this particular interval
4787 /* In case we only want to detect an overload (meaning no bound propagation) we can skip the interval; this is
4788 * the case if the free energy (the energy which is not occupied by any core) is smaller than the previous minimum
4799 freeenergy = capacity * ((SCIP_Longint) end - lct) - coreEnergyAfterLct[v] + coreEnergyAfterEnd;
4803 SCIPdebugMsg(scip, "skip latest completion time <%d> (minimum available energy <%" SCIP_LONGINT_FORMAT ">, free energy <%" SCIP_LONGINT_FORMAT ">)\n", lct, minavailable, freeenergy);
4819 /* loop over the job in non-increasing order w.r.t. the earliest start time; these earliest start time are
4820 * defining the beginning of the time interval under investigation; Thereby, the time interval gets wider and
4841 /* if the job starts after the current end, we can skip it and do not need to consider it again since the
4850 /* check if the interval has a size such that the total energy fits, if so we can skip all intervals with the
4870 /* in case the earliest start time is equal to minbegin, the job lies completely within the time window under
4879 SCIP_CALL( tightenUbTTEF(scip, conshdlrdata, nvars, vars, durations, demands, capacity, hmin, hmax,
4880 var, duration, demand, est, lst, lct, minbegin, end, minavailable, &(newubs[idx]), &(ubinferinfos[idx]),
4887 SCIPdebugMsg(scip, "check variable <%s>[%g,%g] (duration %d, demands %d, est <%d>, lst of free part <%d>\n",
4888 SCIPvarGetName(var), SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var), duration, demand, est, lst);
4893 /* if the earliest start time is smaller than hmin we can stop here since the next job will not decrease the
4913 /* compute the flexible energy which is part of the time interval for sure if the job is scheduled
4925 /* compute the flexible energy of the job which is not part of flexible energy of the time interval */
4941 freeenergy = capacity * ((SCIP_Longint) end - begin) - flexenergy - coreEnergyAfterEst[i] + coreEnergyAfterEnd;
4946 SCIPdebugMsg(scip, "analyze overload within time window [%d,%d) capacity %d\n", begin, end, capacity);
4963 /* for the statistic we count the number of times a cutoff was detected due the time-time-edge-finding */
4964 SCIPstatistic( SCIPconshdlrGetData(SCIPfindConshdlr(scip, CONSHDLR_NAME))->ncutoffoverloadTTEF++ );
4969 /* check if the available energy is not sufficent to schedule the flexible energy of the best candidate job */
4980 energy = freeenergy + (computeCoreWithInterval(begin, end, ect, lst) + MAX(0, (SCIP_Longint) end - lsts[lbcand])) * demands[lbcand];
5035/** propagate the lower bounds and "opportunistically" the upper bounds using the time-table edge-finding algorithm */
5049 int* lbinferinfos, /**< array to store the inference information for the lower bound changes */
5050 int* ubinferinfos, /**< array to store the inference information for the upper bound changes */
5051 int* ects, /**< array of earliest completion time of the flexible part in the same order as the variables */
5053 int* perm, /**< permutation of the variables w.r.t. the non-decreasing order of the latest completion times */
5059 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
5100 /* check if the smallest interval has a size such that the total energy fits, if so we can skip the propagator */
5106 /* loop over all variable in non-decreasing order w.r.t. the earliest start times; thereby, the earliest start times
5120 /* if the earliest start time is smaller then hmin an infeasibility cannot be detected, since before hmin an
5130 /* if the latest earliest start time equals to previous start time, we can continue since this particular interval
5149 /* loop over the job in non-decreasing order w.r.t. the latest completion time; these latest completion times are
5150 * defining the ending of the time interval under investigation; thereby, the time interval gets wider and wider
5170 /* if the job has a latest completion time before the the current start, we can skip it and do not need to
5171 * consider it again since the earliest start times (which define the start) are scant in non-decreasing order
5179 /* check if the interval has a size such that the total energy fits, if so we can skip all intervals which
5199 /* in case the latest completion time is equal to minend, the job lies completely within the time window under
5208 SCIP_CALL( tightenLbTTEF(scip, conshdlrdata, nvars, vars, durations, demands, capacity, hmin, hmax,
5209 var, duration, demand, est, ect, lct, begin, minend, minavailable, &(newlbs[idx]), &(lbinferinfos[idx]),
5216 SCIPdebugMsg(scip, "check variable <%s>[%g,%g] (duration %d, demands %d, est <%d>, ect of free part <%d>\n",
5217 SCIPvarGetName(var), SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var), duration, demand, est, ect);
5222 /* if the latest completion time is larger than hmax we can stop here since the next job will not decrease the
5242 /* compute the flexible energy which is part of the time interval for sure if the job is scheduled
5254 /* compute the flexible energy of the job which is not part of flexible energy of the time interval */
5270 freeenergy = capacity * ((SCIP_Longint) end - begin) - flexenergy - coreEnergyAfterStart + coreEnergyAfterLct[i];
5275 SCIPdebugMsg(scip, "analyze overload within time window [%d,%d) capacity %d\n", begin, end, capacity);
5292 /* for the statistic we count the number of times a cutoff was detected due the time-time-edge-finding */
5293 SCIPstatistic( SCIPconshdlrGetData(SCIPfindConshdlr(scip, CONSHDLR_NAME))->ncutoffoverloadTTEF++ );
5298 /* check if the available energy is not sufficent to schedule the flexible energy of the best candidate job */
5312 energy = freeenergy + (computeCoreWithInterval(begin, end, ect, lst) + MAX(0, (SCIP_Longint) ects[ubcand] - begin)) * demands[ubcand];
5366/** checks whether the instance is infeasible due to a overload within a certain time frame using the idea of time-table
5370 * - Petr Vilim, "Timetable Edge Finding Filtering Algorithm for Discrete Cumulative Resources", In: Tobias
5371 * Achterberg and J. Christopher Beck (Eds.), Integration of AI and OR Techniques in Constraint Programming for
5373 * - Andreas Schutt, Thibaut Feydy, and Peter J. Stuckey, "Explaining Time-Table-Edge-Finding Propagation for the
5391 SCIP_Bool* explanation, /**< bool array which marks the variable which are part of the explanation if a cutoff was detected, or NULL */
5437 /* we need to buffer the bound changes since the propagation algorithm cannot handle new bound dynamically */
5447 collectDataTTEF(scip, nvars, vars, durations, demands, hmin, hmax, permests, ests, permlcts, lcts, ects, lsts, flexenergies);
5453 /* compute for the different earliest start and latest completion time the core energy of the corresponding time
5459 SCIP_CALL( propagateUbTTEF(scip, conshdlrdata, nvars, vars, durations, demands, capacity, hmin, hmax,
5461 permests, ests, lcts, coreEnergyAfterEst, coreEnergyAfterLct, initialized, explanation, cutoff) );
5464 SCIP_CALL( propagateLbTTEF(scip, conshdlrdata, nvars, vars, durations, demands, capacity, hmin, hmax,
5466 permlcts, ests, lcts, coreEnergyAfterEst, coreEnergyAfterLct, initialized, explanation, cutoff) );
5481 SCIP_CALL( SCIPtightenVarLb(scip, vars[v], (SCIP_Real)newlbs[v], TRUE, &infeasible, &tightened) );
5484 /* since we change first the lower bound of the variable an infeasibilty should not be detected */
5502 SCIP_CALL( SCIPtightenVarUb(scip, vars[v], (SCIP_Real)newubs[v], TRUE, &infeasible, &tightened) );
5505 /* since upper bound was compute w.r.t. the "old" bound the previous lower bound update together with this upper
5510 /* a small performance improvement is possible here: if the tighten...TEFF and propagate...TEFF methods would
5511 * return not only the inferinfos, but the actual begin and end values, then the infeasibility here could also
5514 if( SCIPisConflictAnalysisApplicable(scip) && inferInfoIsValid(intToInferInfo(ubinferinfos[v])) )