1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB) */ 7 /* */ 8 /* Licensed under the Apache License, Version 2.0 (the "License"); */ 9 /* you may not use this file except in compliance with the License. */ 10 /* You may obtain a copy of the License at */ 11 /* */ 12 /* http://www.apache.org/licenses/LICENSE-2.0 */ 13 /* */ 14 /* Unless required by applicable law or agreed to in writing, software */ 15 /* distributed under the License is distributed on an "AS IS" BASIS, */ 16 /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ 17 /* See the License for the specific language governing permissions and */ 18 /* limitations under the License. */ 19 /* */ 20 /* You should have received a copy of the Apache-2.0 license */ 21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ 22 /* */ 23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 24 25 /**@file cons_orbisack.h 26 * @ingroup CONSHDLRS 27 * @brief constraint handler for orbisack constraints 28 * @author Christopher Hojny 29 * 30 * The constraint works on two vectors of variables, which are interpreted as columns of a matrix such that the first 31 * column is lexicographically not smaller than the second. 32 */ 33 34 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 35 36 #ifndef __SCIP_CONS_ORBISACK_H__ 37 #define __SCIP_CONS_ORBISACK_H__ 38 39 #include "scip/def.h" 40 #include "scip/type_cons.h" 41 #include "scip/type_retcode.h" 42 #include "scip/type_scip.h" 43 #include "scip/type_sol.h" 44 #include "scip/type_var.h" 45 46 #ifdef __cplusplus 47 extern "C" { 48 #endif 49 50 51 /** creates the handler for orbisack constraints and includes it in SCIP 52 * 53 * @ingroup ConshdlrIncludes 54 */ 55 SCIP_EXPORT 56 SCIP_RETCODE SCIPincludeConshdlrOrbisack( 57 SCIP* scip /**< SCIP data structure */ 58 ); 59 60 /**@addtogroup CONSHDLRS 61 * 62 * @{ 63 * 64 * @name Orbisack Constraints 65 * 66 * @{ 67 * 68 * This constraint handler can be used to handle symmetries in certain 0/1-programs. The principle 69 * structure is that some variables can be ordered in matrix form with two columns, such that 70 * permuting both columns does not change the validity and objective function value of a solution. 71 * That is, there exists a permutation symmetry of the program that permutes the variables of the 72 * first and second column row-wise. 73 * 74 * In more mathematical terms the structure has to be as follows: There are 0/1-variables 75 * \f$x_{ij}\f$, \f$i \in \{1, \dots, n\}\f$, \f$j \in \{1, 2\}\f$. Permuting columns of 76 * \f$x\f$ does not change the validity and objective function value of any feasible solution. 77 */ 78 79 80 /** checks whether a given binary solution is feasible for the orbisack */ 81 SCIP_EXPORT 82 SCIP_RETCODE SCIPcheckSolutionOrbisack( 83 SCIP* scip, /**< SCIP data structure */ 84 SCIP_SOL* sol, /**< solution to check for feasibility */ 85 SCIP_VAR** vars1, /**< variables of first column */ 86 SCIP_VAR** vars2, /**< variables of second column */ 87 int nrows, /**< number of rows */ 88 SCIP_Bool printreason, /**< whether reason for infeasibility should be printed */ 89 SCIP_Bool* feasible /**< memory address to store whether sol is feasible */ 90 ); 91 92 /** creates and captures a orbisack constraint 93 * 94 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 95 */ 96 SCIP_EXPORT 97 SCIP_RETCODE SCIPcreateConsOrbisack( 98 SCIP* scip, /**< SCIP data structure */ 99 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 100 const char* name, /**< name of constraint */ 101 SCIP_VAR*const* vars1, /**< first column matrix of variables on which the symmetry acts */ 102 SCIP_VAR*const* vars2, /**< second column matrix of variables on which the symmetry acts */ 103 int nrows, /**< number of rows in variable matrix */ 104 SCIP_Bool ispporbisack, /**< whether the orbisack is a packing/partitioning orbisack */ 105 SCIP_Bool isparttype, /**< whether the orbisack is a partitioning orbisack */ 106 SCIP_Bool ismodelcons, /**< whether the orbisack is a model constraint */ 107 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? 108 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ 109 SCIP_Bool separate, /**< should the constraint be separated during LP processing? 110 * Usually set to TRUE. */ 111 SCIP_Bool enforce, /**< should the constraint be enforced during node processing? 112 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 113 SCIP_Bool check, /**< should the constraint be checked for feasibility? 114 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 115 SCIP_Bool propagate, /**< should the constraint be propagated during node processing? 116 * Usually set to TRUE. */ 117 SCIP_Bool local, /**< is constraint only valid locally? 118 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ 119 SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? 120 * Usually set to FALSE. In column generation applications, set to TRUE if pricing 121 * adds coefficients to this constraint. */ 122 SCIP_Bool dynamic, /**< is constraint subject to aging? 123 * Usually set to FALSE. Set to TRUE for own cuts which 124 * are separated as constraints. */ 125 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? 126 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ 127 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even 128 * if it may be moved to a more global node? 129 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ 130 ); 131 132 /** creates and captures an orbisack constraint in its most basic variant 133 * 134 * All constraint flags set to their default values, which can be set afterwards using SCIPsetConsFLAGNAME() in scip.h. 135 * 136 * @see SCIPcreateConsOrbisack() for the default constraint flag configuration 137 * 138 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 139 */ 140 SCIP_EXPORT 141 SCIP_RETCODE SCIPcreateConsBasicOrbisack( 142 SCIP* scip, /**< SCIP data structure */ 143 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 144 const char* name, /**< name of constraint */ 145 SCIP_VAR** vars1, /**< first column of matrix of variables on which the symmetry acts */ 146 SCIP_VAR** vars2, /**< second column of matrix of variables on which the symmetry acts */ 147 int nrows, /**< number of rows in constraint matrix */ 148 SCIP_Bool ispporbisack, /**< whether the orbisack is a packing/partitioning orbisack */ 149 SCIP_Bool isparttype, /**< whether the orbisack is a partitioning orbisack */ 150 SCIP_Bool ismodelcons /**< whether the orbisack is a model constraint */ 151 ); 152 153 /** @} */ 154 155 /** @} */ 156 157 #ifdef __cplusplus 158 } 159 #endif 160 161 #endif 162