/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* 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 implics.h * @ingroup INTERNALAPI * @brief methods for implications, variable bounds, and cliques * @author Tobias Achterberg */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_IMPLICS_H__ #define __SCIP_IMPLICS_H__ #include "blockmemshell/memory.h" #include "scip/def.h" #include "scip/type_branch.h" #include "scip/type_event.h" #include "scip/type_implics.h" #include "scip/type_lp.h" #include "scip/type_prob.h" #include "scip/type_reopt.h" #include "scip/type_retcode.h" #include "scip/type_set.h" #include "scip/type_stat.h" #include "scip/type_tree.h" #include "scip/type_var.h" #ifdef NDEBUG #include "scip/pub_implics.h" #include "scip/struct_implics.h" #endif #ifdef __cplusplus extern "C" { #endif /* * Methods for Variable Bounds */ /** frees a variable bounds data structure */ void SCIPvboundsFree( SCIP_VBOUNDS** vbounds, /**< pointer to store variable bounds data structure */ BMS_BLKMEM* blkmem /**< block memory */ ); /** adds a variable bound to the variable bounds data structure */ SCIP_RETCODE SCIPvboundsAdd( SCIP_VBOUNDS** vbounds, /**< pointer to variable bounds data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_BOUNDTYPE vboundtype, /**< type of variable bound (LOWER or UPPER) */ SCIP_VAR* var, /**< variable z in x <= b*z + d or x >= b*z + d */ SCIP_Real coef, /**< coefficient b in x <= b*z + d or x >= b*z + d */ SCIP_Real constant, /**< constant d in x <= b*z + d or x >= b*z + d */ SCIP_Bool* added /**< pointer to store whether the variable bound was added */ ); /** removes from variable x a variable bound x >=/<= b*z + d with binary or integer z */ SCIP_RETCODE SCIPvboundsDel( SCIP_VBOUNDS** vbounds, /**< pointer to variable bounds data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_VAR* vbdvar, /**< variable z in x >=/<= b*z + d */ SCIP_Bool negativecoef /**< is coefficient b negative? */ ); /** reduces the number of variable bounds stored in the given variable bounds data structure */ void SCIPvboundsShrink( SCIP_VBOUNDS** vbounds, /**< pointer to variable bounds data structure */ BMS_BLKMEM* blkmem, /**< block memory */ int newnvbds /**< new number of variable bounds */ ); /** gets number of variable bounds contained in given variable bounds data structure */ int SCIPvboundsGetNVbds( SCIP_VBOUNDS* vbounds /**< variable bounds data structure */ ); /** gets array of variables contained in given variable bounds data structure */ SCIP_VAR** SCIPvboundsGetVars( SCIP_VBOUNDS* vbounds /**< variable bounds data structure */ ); /** gets array of coefficients contained in given variable bounds data structure */ SCIP_Real* SCIPvboundsGetCoefs( SCIP_VBOUNDS* vbounds /**< variable bounds data structure */ ); /** gets array of constants contained in given variable bounds data structure */ SCIP_Real* SCIPvboundsGetConstants( SCIP_VBOUNDS* vbounds /**< variable bounds data structure */ ); #ifdef NDEBUG /* In optimized mode, the function calls are overwritten by defines to reduce the number of function calls and * speed up the algorithms. */ #define SCIPvboundsGetNVbds(vbounds) ((vbounds) != NULL ? (vbounds)->len : 0) #define SCIPvboundsGetVars(vbounds) ((vbounds) != NULL ? (vbounds)->vars : NULL) #define SCIPvboundsGetCoefs(vbounds) ((vbounds) != NULL ? (vbounds)->coefs : NULL) #define SCIPvboundsGetConstants(vbounds) ((vbounds) != NULL ? (vbounds)->constants : NULL) #endif /* * Methods for Implications */ /** frees an implications data structure */ void SCIPimplicsFree( SCIP_IMPLICS** implics, /**< pointer of implications data structure to free */ BMS_BLKMEM* blkmem /**< block memory */ ); /** adds an implication x == 0/1 -> y <= b or y >= b to the implications data structure; * the implication must be non-redundant */ SCIP_RETCODE SCIPimplicsAdd( SCIP_IMPLICS** implics, /**< pointer to implications data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_STAT* stat, /**< problem statistics */ SCIP_Bool varfixing, /**< FALSE if implication for x == 0 has to be added, TRUE for x == 1 */ SCIP_VAR* implvar, /**< variable y in implication y <= b or y >= b */ SCIP_BOUNDTYPE impltype, /**< type of implication y <= b (SCIP_BOUNDTYPE_UPPER) or y >= b (SCIP_BOUNDTYPE_LOWER) */ SCIP_Real implbound, /**< bound b in implication y <= b or y >= b */ SCIP_Bool isshortcut, /**< is the implication a shortcut, i.e., added as part of the transitive closure of another implication? */ SCIP_Bool* conflict, /**< pointer to store whether implication causes a conflict for variable x */ SCIP_Bool* added /**< pointer to store whether the implication was added */ ); /** removes the implication x <= 0 or x >= 1 ==> y <= b or y >= b from the implications data structure */ SCIP_RETCODE SCIPimplicsDel( SCIP_IMPLICS** implics, /**< pointer to implications data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_Bool varfixing, /**< FALSE if y should be removed from implications for x <= 0, TRUE for x >= 1 */ SCIP_VAR* implvar, /**< variable y in implication y <= b or y >= b */ SCIP_BOUNDTYPE impltype /**< type of implication y <= b (SCIP_BOUNDTYPE_UPPER) or y >= b (SCIP_BOUNDTYPE_LOWER) */ ); /** returns which implications on given variable y are contained in implications for x == 0 or x == 1 */ void SCIPimplicsGetVarImplics( SCIP_IMPLICS* implics, /**< implications data structure */ SCIP_Bool varfixing, /**< FALSE if y should be searched in implications for x == 0, TRUE for x == 1 */ SCIP_VAR* implvar, /**< variable y to search for */ SCIP_Bool* haslowerimplic, /**< pointer to store whether there exists an implication y >= l */ SCIP_Bool* hasupperimplic /**< pointer to store whether there exists an implication y <= u */ ); /** returns whether an implication y <= b or y >= b is contained in implications for x == 0 or x == 1 */ SCIP_Bool SCIPimplicsContainsImpl( SCIP_IMPLICS* implics, /**< implications data structure */ SCIP_Bool varfixing, /**< FALSE if y should be searched in implications for x == 0, TRUE for x == 1 */ SCIP_VAR* implvar, /**< variable y to search for */ SCIP_BOUNDTYPE impltype /**< type of implication y <=/>= b to search for */ ); /** gets number of implications for a given binary variable fixing */ int SCIPimplicsGetNImpls( SCIP_IMPLICS* implics, /**< implication data */ SCIP_Bool varfixing /**< should the implications on var == FALSE or var == TRUE be returned? */ ); /** gets array with implied variables for a given binary variable fixing */ SCIP_VAR** SCIPimplicsGetVars( SCIP_IMPLICS* implics, /**< implication data */ SCIP_Bool varfixing /**< should the implications on var == FALSE or var == TRUE be returned? */ ); /** gets array with implication types for a given binary variable fixing */ SCIP_BOUNDTYPE* SCIPimplicsGetTypes( SCIP_IMPLICS* implics, /**< implication data */ SCIP_Bool varfixing /**< should the implications on var == FALSE or var == TRUE be returned? */ ); /** gets array with implication bounds for a given binary variable fixing */ SCIP_Real* SCIPimplicsGetBounds( SCIP_IMPLICS* implics, /**< implication data */ SCIP_Bool varfixing /**< should the implications on var == FALSE or var == TRUE be returned? */ ); /** Gets array with unique implication identifiers for a given binary variable fixing. * If an implication is a shortcut, i.e., it was added as part of the transitive closure of another implication, * its id is negative, otherwise it is nonnegative. */ int* SCIPimplicsGetIds( SCIP_IMPLICS* implics, /**< implication data */ SCIP_Bool varfixing /**< should the implications on var == FALSE or var == TRUE be returned? */ ); #ifdef NDEBUG /* In optimized mode, the function calls are overwritten by defines to reduce the number of function calls and * speed up the algorithms. */ #define SCIPimplicsGetNImpls(implics, varfixing) ((implics) != NULL ? (implics)->nimpls[varfixing] : 0) #define SCIPimplicsGetNBinImpls(implics, varfixing) ((implics) != NULL ? (implics)->nbinimpls[varfixing] : 0) #define SCIPimplicsGetVars(implics, varfixing) ((implics) != NULL ? (implics)->vars[varfixing] : NULL) #define SCIPimplicsGetTypes(implics, varfixing) ((implics) != NULL ? (implics)->types[varfixing] : NULL) #define SCIPimplicsGetBounds(implics, varfixing) ((implics) != NULL ? (implics)->bounds[varfixing] : NULL) #define SCIPimplicsGetIds(implics, varfixing) ((implics) != NULL ? (implics)->ids[varfixing] : NULL) #endif /* * methods for cliques */ /** adds a single variable to the given clique */ SCIP_RETCODE SCIPcliqueAddVar( SCIP_CLIQUE* clique, /**< clique data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_VAR* var, /**< variable to add to the clique */ SCIP_Bool value, /**< value of the variable in the clique */ SCIP_Bool* doubleentry, /**< pointer to store whether the variable and value occurs twice in the clique */ SCIP_Bool* oppositeentry /**< pointer to store whether the variable with opposite value is in the clique */ ); /** removes a single variable from the given clique */ void SCIPcliqueDelVar( SCIP_CLIQUE* clique, /**< clique data structure */ SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ SCIP_VAR* var, /**< variable to remove from the clique */ SCIP_Bool value /**< value of the variable in the clique */ ); /** frees a clique list data structure */ void SCIPcliquelistFree( SCIP_CLIQUELIST** cliquelist, /**< pointer to the clique list data structure */ BMS_BLKMEM* blkmem /**< block memory */ ); /** adds a clique to the clique list */ SCIP_RETCODE SCIPcliquelistAdd( SCIP_CLIQUELIST** cliquelist, /**< pointer to the clique list data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_Bool value, /**< value of the variable for which the clique list should be extended */ SCIP_CLIQUE* clique /**< clique that should be added to the clique list */ ); /** removes a clique from the clique list */ SCIP_RETCODE SCIPcliquelistDel( SCIP_CLIQUELIST** cliquelist, /**< pointer to the clique list data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_Bool value, /**< value of the variable for which the clique list should be reduced */ SCIP_CLIQUE* clique /**< clique that should be deleted from the clique list */ ); /** returns whether the given clique lists have a non-empty intersection, i.e. whether there is a clique that appears * in both lists */ SCIP_Bool SCIPcliquelistsHaveCommonClique( SCIP_CLIQUELIST* cliquelist1, /**< first clique list data structure */ SCIP_Bool value1, /**< value of first variable */ SCIP_CLIQUELIST* cliquelist2, /**< second clique list data structure */ SCIP_Bool value2 /**< value of second variable */ ); /** removes all listed entries from the cliques */ void SCIPcliquelistRemoveFromCliques( SCIP_CLIQUELIST* cliquelist, /**< clique list data structure */ SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ SCIP_VAR* var, /**< active problem variable the clique list belongs to */ SCIP_Bool irrelevantvar /**< has the variable become irrelevant, meaning that equality * cliques need to be relaxed? */ ); /** creates a clique table data structure */ SCIP_RETCODE SCIPcliquetableCreate( SCIP_CLIQUETABLE** cliquetable, /**< pointer to store clique table data structure */ SCIP_SET* set, /**< global SCIP settings */ BMS_BLKMEM* blkmem /**< block memory */ ); /** frees a clique table data structure */ SCIP_RETCODE SCIPcliquetableFree( SCIP_CLIQUETABLE** cliquetable, /**< pointer to store clique table data structure */ BMS_BLKMEM* blkmem /**< block memory */ ); /** adds a clique to the clique table, using the given values for the given variables; * performs implications if the clique contains the same variable twice */ SCIP_RETCODE SCIPcliquetableAdd( SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_STAT* stat, /**< problem statistics */ SCIP_PROB* transprob, /**< transformed problem */ SCIP_PROB* origprob, /**< original problem */ SCIP_TREE* tree, /**< branch and bound tree if in solving stage */ SCIP_REOPT* reopt, /**< reoptimization data structure */ SCIP_LP* lp, /**< current LP data */ SCIP_BRANCHCAND* branchcand, /**< branching candidate storage */ SCIP_EVENTQUEUE* eventqueue, /**< event queue */ SCIP_VAR** vars, /**< binary variables in the clique: at most one can be set to the given value */ SCIP_Bool* values, /**< values of the variables in the clique; NULL to use TRUE for all vars */ int nvars, /**< number of variables in the clique */ SCIP_Bool isequation, /**< is the clique an equation or an inequality? */ SCIP_Bool* infeasible, /**< pointer to store whether an infeasibility was detected */ int* nbdchgs /**< pointer to count the number of performed bound changes, or NULL */ ); /** removes all empty and single variable cliques from the clique table; removes double entries from the clique table * * @note cliques can be processed several times by this method */ SCIP_RETCODE SCIPcliquetableCleanup( SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_SET* set, /**< global SCIP settings */ SCIP_STAT* stat, /**< problem statistics */ SCIP_PROB* transprob, /**< transformed problem */ SCIP_PROB* origprob, /**< original problem */ SCIP_TREE* tree, /**< branch and bound tree if in solving stage */ SCIP_REOPT* reopt, /**< reoptimization data structure */ SCIP_LP* lp, /**< current LP data */ SCIP_BRANCHCAND* branchcand, /**< branching candidate storage */ SCIP_EVENTQUEUE* eventqueue, /**< event queue */ int* nchgbds, /**< pointer to store number of fixed variables */ SCIP_Bool* infeasible /**< pointer to store whether an infeasibility was detected */ ); /** computes connected components of the clique graph * * use depth-first search similarly to the components presolver/constraint handler, representing a clique as a * path to reduce memory usage, but leaving the connected components the same * * an update becomes necessary if a clique gets added with variables from different components */ SCIP_RETCODE SCIPcliquetableComputeCliqueComponents( SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ SCIP_SET* set, /**< global SCIP settings */ BMS_BLKMEM* blkmem, /**< block memory */ SCIP_VAR** vars, /**< array of problem variables, sorted by variable type */ int nbinvars, /**< number of binary variables */ int nintvars, /**< number of integer variables */ int nimplvars /**< number of implicit integer variables */ ); /** returns the index of the connected component of the clique graph that the variable belongs to, or -1 */ int SCIPcliquetableGetVarComponentIdx( SCIP_CLIQUETABLE* cliquetable, /**< clique table data structure */ SCIP_VAR* var /**< problem variable */ ); /** returns the number of cliques stored in the clique list */ int SCIPcliquelistGetNCliques( SCIP_CLIQUELIST* cliquelist, /**< clique list data structure */ SCIP_Bool value /**< value of the variable for which the cliques should be returned */ ); /** returns the cliques stored in the clique list, or NULL if the clique list is empty */ SCIP_CLIQUE** SCIPcliquelistGetCliques( SCIP_CLIQUELIST* cliquelist, /**< clique list data structure */ SCIP_Bool value /**< value of the variable for which the cliques should be returned */ ); /** checks whether variable is contained in all cliques of the cliquelist */ void SCIPcliquelistCheck( SCIP_CLIQUELIST* cliquelist, /**< clique list data structure */ SCIP_VAR* var /**< variable, the clique list belongs to */ ); /** gets the number of cliques stored in the clique table */ int SCIPcliquetableGetNCliques( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); /** gets the number of cliques created so far by the clique table */ int SCIPcliquetableGetNCliquesCreated( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); /** gets the array of cliques stored in the clique table */ SCIP_CLIQUE** SCIPcliquetableGetCliques( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); /** gets the number of entries in the whole clique table */ SCIP_Longint SCIPcliquetableGetNEntries( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); /** returns the number of clique components, or -1 if update is necessary first */ int SCIPcliquetableGetNCliqueComponents( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); /** returns TRUE iff the connected clique components need an update (because new cliques were added) */ SCIP_Bool SCIPcliquetableNeedsComponentUpdate( SCIP_CLIQUETABLE* cliquetable /**< clique table data structure */ ); #ifdef NDEBUG /* In optimized mode, the function calls are overwritten by defines to reduce the number of function calls and * speed up the algorithms. */ #define SCIPcliquelistGetNCliques(cliquelist, value) ((cliquelist) != NULL ? (cliquelist)->ncliques[value] : 0) #define SCIPcliquelistGetCliques(cliquelist, value) ((cliquelist) != NULL ? (cliquelist)->cliques[value] : NULL) #define SCIPcliquelistCheck(cliquelist, var) /**/ #define SCIPcliquetableGetNCliques(cliquetable) ((cliquetable)->ncliques) #define SCIPcliquetableGetCliques(cliquetable) ((cliquetable)->cliques) #define SCIPcliquetableGetNEntries(cliquetable) ((cliquetable)->nentries) #define SCIPcliquetableGetNCliqueComponents(cliquetable) (cliquetable->compsfromscratch ? -1 : cliquetable->ncliquecomponents) #define SCIPcliquetableNeedsComponentUpdate(cliquetable) (cliquetable->compsfromscratch || cliquetable->djset == NULL) #endif #ifdef __cplusplus } #endif #endif