/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright 2002-2022 Zuse Institute Berlin */ /* */ /* Licensed under the Apache License, Version 2.0 (the "License"); */ /* you may not use this file except in compliance with the License. */ /* You may obtain a copy of the License at */ /* */ /* http://www.apache.org/licenses/LICENSE-2.0 */ /* */ /* Unless required by applicable law or agreed to in writing, software */ /* distributed under the License is distributed on an "AS IS" BASIS, */ /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ /* See the License for the specific language governing permissions and */ /* limitations under the License. */ /* */ /* You should have received a copy of the Apache-2.0 license */ /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file cons_sos1.h * @ingroup CONSHDLRS * @brief constraint handler for SOS type 1 constraints * @author Tobias Fischer * @author Marc Pfetsch * */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_CONS_SOS1_H__ #define __SCIP_CONS_SOS1_H__ #include "scip/def.h" #include "scip/type_cons.h" #include "scip/type_misc.h" #include "scip/type_retcode.h" #include "scip/type_scip.h" #include "scip/type_sol.h" #include "scip/type_var.h" #ifdef __cplusplus extern "C" { #endif /** creates the handler for SOS1 constraints and includes it in SCIP * * @ingroup ConshdlrIncludes * */ SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrSOS1( SCIP* scip /**< SCIP data structure */ ); /**@addtogroup CONSHDLRS * * @{ * * @name Specially Ordered Set (SOS) Type 1 Constraints * * @{ * * A specially ordered set of type 1 (SOS1) is a sequence of variables such that at most one * variable is nonzero. The special case of two variables arises, for instance, from equilibrium or * complementary conditions like \f$x \cdot y = 0\f$. Note that it is in principle allowed that a * variable appears twice, but it then can be fixed to 0. */ /** creates and captures an SOS1 constraint * * We set the constraint to not be modifable. If the weights are non * NULL, the variables are ordered according to these weights (in * ascending order). * * @note The constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons(). */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ int nvars, /**< number of variables in the constraint */ SCIP_VAR** vars, /**< array with variables of constraint entries */ SCIP_Real* weights, /**< weights determining the variable order, or NULL if natural order should be used */ SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ SCIP_Bool separate, /**< should the constraint be separated during LP processing? * Usually set to TRUE. */ SCIP_Bool enforce, /**< should the constraint be enforced during node processing? * TRUE for model constraints, FALSE for additional, redundant constraints. */ SCIP_Bool check, /**< should the constraint be checked for feasibility? * TRUE for model constraints, FALSE for additional, redundant constraints. */ SCIP_Bool propagate, /**< should the constraint be propagated during node processing? * Usually set to TRUE. */ SCIP_Bool local, /**< is constraint only valid locally? * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ SCIP_Bool dynamic, /**< is constraint subject to aging? * Usually set to FALSE. Set to TRUE for own cuts which * are separated as constraints. */ SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even * if it may be moved to a more global node? * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ ); /** creates and captures an SOS1 constraint * in its most basic variant, i. e., with all constraint flags set to their default values, which can be set * afterwards using SCIPsetConsFLAGNAME() in scip.h * * @see SCIPcreateConsSOS1() for the default constraint flag configuration * * @warning Do NOT set the constraint to be modifiable manually, because this might lead * to wrong results as the variable array will not be resorted * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsBasicSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ int nvars, /**< number of variables in the constraint */ SCIP_VAR** vars, /**< array with variables of constraint entries */ SCIP_Real* weights /**< weights determining the variable order, or NULL if natural order should be used */ ); /** adds variable to SOS1 constraint, the position is determined by the given weight */ SCIP_EXPORT SCIP_RETCODE SCIPaddVarSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint */ SCIP_VAR* var, /**< variable to add to the constraint */ SCIP_Real weight /**< weight determining position of variable */ ); /** appends variable to SOS1 constraint */ SCIP_EXPORT SCIP_RETCODE SCIPappendVarSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons, /**< constraint */ SCIP_VAR* var /**< variable to add to the constraint */ ); /** gets number of variables in SOS1 constraint */ SCIP_EXPORT int SCIPgetNVarsSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint */ ); /** gets array of variables in SOS1 constraint */ SCIP_EXPORT SCIP_VAR** SCIPgetVarsSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets array of weights in SOS1 constraint (or NULL if not existent) */ SCIP_EXPORT SCIP_Real* SCIPgetWeightsSOS1( SCIP* scip, /**< SCIP data structure */ SCIP_CONS* cons /**< constraint data */ ); /** gets conflict graph of SOS1 constraints (or NULL if not existent) * * @note The conflict graph is globally valid; local changes are not taken into account. */ SCIP_EXPORT SCIP_DIGRAPH* SCIPgetConflictgraphSOS1( SCIP_CONSHDLR* conshdlr /**< SOS1 constraint handler */ ); /** gets number of problem variables that are part of the SOS1 conflict graph */ SCIP_EXPORT int SCIPgetNSOS1Vars( SCIP_CONSHDLR* conshdlr /**< SOS1 constraint handler */ ); /** returns whether variable is part of the SOS1 conflict graph */ SCIP_EXPORT SCIP_Bool SCIPvarIsSOS1( SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */ SCIP_VAR* var /**< variable */ ); /** returns node of variable in the conflict graph or -1 if variable is not part of the SOS1 conflict graph */ SCIP_EXPORT int SCIPvarGetNodeSOS1( SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */ SCIP_VAR* var /**< variable */ ); /** returns variable that belongs to a given node from the conflict graph */ SCIP_EXPORT SCIP_VAR* SCIPnodeGetVarSOS1( SCIP_DIGRAPH* conflictgraph, /**< conflict graph */ int node /**< node from the conflict graph */ ); /** based on solution values of the variables, fixes variables to zero to turn all SOS1 constraints feasible */ SCIP_EXPORT SCIP_RETCODE SCIPmakeSOS1sFeasible( SCIP* scip, /**< SCIP pointer */ SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */ SCIP_SOL* sol, /**< solution */ SCIP_Bool* changed, /**< pointer to store whether the solution has been changed */ SCIP_Bool* success /**< pointer to store whether SOS1 constraints have been turned feasible and * solution was good enough */ ); /** @} */ /** @} */ #ifdef __cplusplus } #endif #endif