/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* 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_orbisack.h * @ingroup CONSHDLRS * @brief constraint handler for orbisack constraints * @author Christopher Hojny * * The constraint works on two vectors of variables, which are interpreted as columns of a matrix such that the first * column is lexicographically not smaller than the second. */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_CONS_ORBISACK_H__ #define __SCIP_CONS_ORBISACK_H__ #include "scip/def.h" #include "scip/type_cons.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 orbisack constraints and includes it in SCIP * * @ingroup ConshdlrIncludes */ SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrOrbisack( SCIP* scip /**< SCIP data structure */ ); /**@addtogroup CONSHDLRS * * @{ * * @name Orbisack Constraints * * @{ * * This constraint handler can be used to handle symmetries in certain 0/1-programs. The principle * structure is that some variables can be ordered in matrix form with two columns, such that * permuting both columns does not change the validity and objective function value of a solution. * That is, there exists a permutation symmetry of the program that permutes the variables of the * first and second column row-wise. * * In more mathematical terms the structure has to be as follows: There are 0/1-variables * \f$x_{ij}\f$, \f$i \in \{1, \dots, n\}\f$, \f$j \in \{1, 2\}\f$. Permuting columns of * \f$x\f$ does not change the validity and objective function value of any feasible solution. */ /** checks whether a given binary solution is feasible for the orbisack */ SCIP_EXPORT SCIP_RETCODE SCIPcheckSolutionOrbisack( SCIP* scip, /**< SCIP data structure */ SCIP_SOL* sol, /**< solution to check for feasibility */ SCIP_VAR** vars1, /**< variables of first column */ SCIP_VAR** vars2, /**< variables of second column */ int nrows, /**< number of rows */ SCIP_Bool printreason, /**< whether reason for infeasibility should be printed */ SCIP_Bool* feasible /**< memory address to store whether sol is feasible */ ); /** creates and captures a orbisack constraint * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsOrbisack( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_VAR*const* vars1, /**< first column matrix of variables on which the symmetry acts */ SCIP_VAR*const* vars2, /**< second column matrix of variables on which the symmetry acts */ int nrows, /**< number of rows in variable matrix */ SCIP_Bool ispporbisack, /**< whether the orbisack is a packing/partitioning orbisack */ SCIP_Bool isparttype, /**< whether the orbisack is a partitioning orbisack */ SCIP_Bool ismodelcons, /**< whether the orbisack is a model constraint */ 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 modifiable, /**< is constraint modifiable (subject to column generation)? * Usually set to FALSE. In column generation applications, set to TRUE if pricing * adds coefficients to this constraint. */ 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 orbisack constraint in its most basic variant * * All constraint flags set to their default values, which can be set afterwards using SCIPsetConsFLAGNAME() in scip.h. * * @see SCIPcreateConsOrbisack() for the default constraint flag configuration * * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() */ SCIP_EXPORT SCIP_RETCODE SCIPcreateConsBasicOrbisack( SCIP* scip, /**< SCIP data structure */ SCIP_CONS** cons, /**< pointer to hold the created constraint */ const char* name, /**< name of constraint */ SCIP_VAR** vars1, /**< first column of matrix of variables on which the symmetry acts */ SCIP_VAR** vars2, /**< second column of matrix of variables on which the symmetry acts */ int nrows, /**< number of rows in constraint matrix */ SCIP_Bool ispporbisack, /**< whether the orbisack is a packing/partitioning orbisack */ SCIP_Bool isparttype, /**< whether the orbisack is a partitioning orbisack */ SCIP_Bool ismodelcons /**< whether the orbisack is a model constraint */ ); /** @} */ /** @} */ #ifdef __cplusplus } #endif #endif