/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright (C) 2002-2020 Konrad-Zuse-Zentrum */ /* fuer Informationstechnik Berlin */ /* */ /* SCIP is distributed under the terms of the ZIB Academic License. */ /* */ /* You should have received a copy of the ZIB Academic License */ /* along with SCIP; see the file COPYING. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file type_prop.h * @ingroup TYPEDEFINITIONS * @brief type definitions for propagators * @author Tobias Achterberg */ /** @defgroup DEFPLUGINS_PROP Default Propagators * @ingroup DEFPLUGINS * @brief implementation files (.c files) of the default propagators of SCIP */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_TYPE_PROP_H__ #define __SCIP_TYPE_PROP_H__ #include "scip/def.h" #include "scip/type_retcode.h" #include "scip/type_result.h" #include "scip/type_scip.h" #include "scip/type_timing.h" #ifdef __cplusplus extern "C" { #endif typedef struct SCIP_Prop SCIP_PROP; /**< propagator */ typedef struct SCIP_PropData SCIP_PROPDATA; /**< locally defined propagator data */ /** copy method for propagator plugins (called when SCIP copies plugins) * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** destructor of propagator to free user data (called when SCIP is exiting) * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPFREE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** initialization method of propagator (called after problem was transformed) * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPINIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** deinitialization method of propagator (called before transformed problem is freed) * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPEXIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** presolving initialization method of propagator (called when presolving is about to begin) * * This method is called when the presolving process is about to begin, even if presolving is turned off. The * propagator may use this call to initialize its presolving data, before the presolving process begins. * * Necessary modifications that have to be performed even if presolving is turned off should be done here or in the * presolving deinitialization call (SCIP_DECL_PROPEXITPRE()). * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPINITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** presolving deinitialization method of propagator (called after presolving has been finished) * * This method is called after the presolving has been finished, even if presolving is turned off. * The propagator may use this call e.g. to clean up its presolving data. * * Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the * problem has already been solved. Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL, * SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD. * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPEXITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** solving process initialization method of propagator (called when branch and bound process is about to begin) * * This method is called when the presolving was finished and the branch and bound process is about to begin. * The propagator may use this call to initialize its branch and bound specific data. * * Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the * problem has already been solved. Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL, * SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD. * * input: * - scip : SCIP main data structure * - prop : the propagator itself */ #define SCIP_DECL_PROPINITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop) /** solving process deinitialization method of propagator (called before branch and bound process data is freed) * * This method is called before the branch and bound process is freed. * The propagator should use this call to clean up its branch and bound data. * * input: * - scip : SCIP main data structure * - prop : the propagator itself * - restart : was this exit solve call triggered by a restart? */ #define SCIP_DECL_PROPEXITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, SCIP_Bool restart) /** presolving method of propagator * * The presolver should go through the variables and constraints and tighten the domains or * constraints. Each tightening should increase the given total numbers of changes. * * input: * - scip : SCIP main data structure * - prop : the propagator itself * - nrounds : number of presolving rounds already done * - presoltiming : current presolving timing * - nnewfixedvars : number of variables fixed since the last call to the presolving method * - nnewaggrvars : number of variables aggregated since the last call to the presolving method * - nnewchgvartypes : number of variable type changes since the last call to the presolving method * - nnewchgbds : number of variable bounds tightened since the last call to the presolving method * - nnewholes : number of domain holes added since the last call to the presolving method * - nnewdelconss : number of deleted constraints since the last call to the presolving method * - nnewaddconss : number of added constraints since the last call to the presolving method * - nnewupgdconss : number of upgraded constraints since the last call to the presolving method * - nnewchgcoefs : number of changed coefficients since the last call to the presolving method * - nnewchgsides : number of changed left or right hand sides since the last call to the presolving method * * @note the counters state the changes since the last call including the changes of this presolving method during its * last call * * @note if the propagator uses dual information for presolving it is nesassary to check via calling SCIPallowWeakDualReds * or SCIPallowStrongDualReds if dual reductions are allowed. * * input/output: * - nfixedvars : pointer to total number of variables fixed of all presolvers * - naggrvars : pointer to total number of variables aggregated of all presolvers * - nchgvartypes : pointer to total number of variable type changes of all presolvers * - nchgbds : pointer to total number of variable bounds tightened of all presolvers * - naddholes : pointer to total number of domain holes added of all presolvers * - ndelconss : pointer to total number of deleted constraints of all presolvers * - naddconss : pointer to total number of added constraints of all presolvers * - nupgdconss : pointer to total number of upgraded constraints of all presolvers * - nchgcoefs : pointer to total number of changed coefficients of all presolvers * - nchgsides : pointer to total number of changed left/right hand sides of all presolvers * * output: * - result : pointer to store the result of the presolving call * * possible return values for *result: * - SCIP_UNBOUNDED : at least one variable is not bounded by any constraint in obj. direction -> problem is unbounded * - SCIP_CUTOFF : at least one constraint is infeasible in the variable's bounds -> problem is infeasible * - SCIP_SUCCESS : the presolving method found a reduction * - SCIP_DIDNOTFIND : the presolving method searched, but did not find a presolving change * - SCIP_DIDNOTRUN : the presolving method was skipped * - SCIP_DELAYED : the presolving method was skipped, but should be called again */ #define SCIP_DECL_PROPPRESOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, int nrounds, SCIP_PRESOLTIMING presoltiming, \ int nnewfixedvars, int nnewaggrvars, int nnewchgvartypes, int nnewchgbds, int nnewholes, \ int nnewdelconss, int nnewaddconss, int nnewupgdconss, int nnewchgcoefs, int nnewchgsides, \ int* nfixedvars, int* naggrvars, int* nchgvartypes, int* nchgbds, int* naddholes, \ int* ndelconss, int* naddconss, int* nupgdconss, int* nchgcoefs, int* nchgsides, SCIP_RESULT* result) /** execution method of propagator * * Searches for domain propagations. The method is called in the node processing loop. * * input: * - scip : SCIP main data structure * - prop : the propagator itself * - proptiming : current point in the node solving loop * - result : pointer to store the result of the propagation call * * possible return values for *result: * - SCIP_CUTOFF : the current node is infeasible for the current domains * - SCIP_REDUCEDDOM : at least one domain reduction was found * - SCIP_DIDNOTFIND : the propagator searched, but did not find a domain reduction * - SCIP_DIDNOTRUN : the propagator was skipped * - SCIP_DELAYED : the propagator was skipped, but should be called again * - SCIP_DELAYNODE : the current node should be postponed (return value only valid for BEFORELP propagation) */ #define SCIP_DECL_PROPEXEC(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, SCIP_PROPTIMING proptiming, SCIP_RESULT* result) /** propagation conflict resolving method of propagator * * This method is called during conflict analysis. If the propagator wants to support conflict analysis, * it should call SCIPinferVarLbProp() or SCIPinferVarUbProp() in domain propagation instead of SCIPchgVarLb() or * SCIPchgVarUb() in order to deduce bound changes on variables. * In the SCIPinferVarLbProp() and SCIPinferVarUbProp() calls, the propagator provides a pointer to itself * and an integer value "inferinfo" that can be arbitrarily chosen. * The propagation conflict resolving method can then be implemented, to provide a "reasons" for the bound * changes, i.e. the bounds of variables at the time of the propagation, that forced the propagator to set the * conflict variable's bound to its current value. It can use the "inferinfo" tag to identify its own propagation * rule and thus identify the "reason" bounds. The bounds that form the reason of the assignment must then be provided * by calls to SCIPaddConflictLb(), SCIPaddConflictUb(), SCIPaddConflictBd(), SCIPaddConflictRelaxedLb(), * SCIPaddConflictRelaxedUb(), SCIPaddConflictRelaxedBd(), and/or SCIPaddConflictBinvar() in the propagation conflict * resolving method. * * See the description of the propagation conflict resolving method of constraint handlers for further details. * * @note if the propagtor uses dual information it is nesassary to check via calling SCIPallowWeakDualReds and * SCIPallowStrongDualReds if dual reductions and propgation with the current cutoff bound, resp., are allowed. * * input: * - scip : SCIP main data structure * - prop : the propagator itself * - infervar : the conflict variable whose bound change has to be resolved * - inferinfo : the user information passed to the corresponding SCIPinferVarLbProp() or SCIPinferVarUbProp() call * - boundtype : the type of the changed bound (lower or upper bound) * - bdchgidx : the index of the bound change, representing the point of time where the change took place * - relaxedbd : the relaxed bound which is sufficient to be explained * * output: * - result : pointer to store the result of the propagation conflict resolving call * * possible return values for *result: * - SCIP_SUCCESS : the conflicting bound change has been successfully resolved by adding all reason bounds * - SCIP_DIDNOTFIND : the conflicting bound change could not be resolved and has to be put into the conflict set * * @note it is sufficient to explain/resolve the relaxed bound */ #define SCIP_DECL_PROPRESPROP(x) SCIP_RETCODE x (SCIP* scip, SCIP_PROP* prop, SCIP_VAR* infervar, int inferinfo, \ SCIP_BOUNDTYPE boundtype, SCIP_BDCHGIDX* bdchgidx, SCIP_Real relaxedbd, SCIP_RESULT* result) #ifdef __cplusplus } #endif #endif