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_sos2.h 26 * @ingroup CONSHDLRS 27 * @brief constraint handler for SOS type 2 constraints 28 * @author Marc Pfetsch 29 * 30 */ 31 32 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 33 34 #ifndef __SCIP_CONS_SOS2_H__ 35 #define __SCIP_CONS_SOS2_H__ 36 37 38 #include "scip/def.h" 39 #include "scip/type_cons.h" 40 #include "scip/type_retcode.h" 41 #include "scip/type_scip.h" 42 #include "scip/type_var.h" 43 44 #ifdef __cplusplus 45 extern "C" { 46 #endif 47 48 /** creates the handler for SOS2 constraints and includes it in SCIP 49 * 50 * @ingroup ConshdlrIncludes 51 * */ 52 SCIP_EXPORT 53 SCIP_RETCODE SCIPincludeConshdlrSOS2( 54 SCIP* scip /**< SCIP data structure */ 55 ); 56 57 /**@addtogroup CONSHDLRS 58 * 59 * @{ 60 * 61 * @name Specially Ordered Set (SOS) Type 2 Constraints 62 * 63 * @{ 64 * 65 * A specially ordered set of type 2 (SOS2) is a sequence of variables such that at most two 66 * variables are nonzero and if two variables are nonzero they must be adjacent in the specified 67 * sequence. Note that it is in principle allowed that a variable appears twice, but it then can be 68 * fixed to 0 if it is at least two apart in the sequence. 69 */ 70 71 /** creates and captures an SOS2 constraint 72 * 73 * We set the constraint to not be modifable. If the weights are non 74 * NULL, the variables are ordered according to these weights (in 75 * ascending order). 76 * 77 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 78 */ 79 SCIP_EXPORT 80 SCIP_RETCODE SCIPcreateConsSOS2( 81 SCIP* scip, /**< SCIP data structure */ 82 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 83 const char* name, /**< name of constraint */ 84 int nvars, /**< number of variables in the constraint */ 85 SCIP_VAR** vars, /**< array with variables of constraint entries */ 86 SCIP_Real* weights, /**< weights determining the variable order, or NULL if natural order should be used */ 87 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? 88 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ 89 SCIP_Bool separate, /**< should the constraint be separated during LP processing? 90 * Usually set to TRUE. */ 91 SCIP_Bool enforce, /**< should the constraint be enforced during node processing? 92 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 93 SCIP_Bool check, /**< should the constraint be checked for feasibility? 94 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 95 SCIP_Bool propagate, /**< should the constraint be propagated during node processing? 96 * Usually set to TRUE. */ 97 SCIP_Bool local, /**< is constraint only valid locally? 98 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ 99 SCIP_Bool dynamic, /**< is constraint subject to aging? 100 * Usually set to FALSE. Set to TRUE for own cuts which 101 * are separated as constraints. */ 102 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? 103 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ 104 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even 105 * if it may be moved to a more global node? 106 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ 107 ); 108 109 /** creates and captures a SOS2 constraint with all constraint flags set to their default values. 110 * 111 * @warning Do NOT set the constraint to be modifiable manually, because this might lead 112 * to wrong results as the variable array will not be resorted 113 * 114 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 115 */ 116 SCIP_EXPORT 117 SCIP_RETCODE SCIPcreateConsBasicSOS2( 118 SCIP* scip, /**< SCIP data structure */ 119 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 120 const char* name, /**< name of constraint */ 121 int nvars, /**< number of variables in the constraint */ 122 SCIP_VAR** vars, /**< array with variables of constraint entries */ 123 SCIP_Real* weights /**< weights determining the variable order, or NULL if natural order should be used */ 124 ); 125 126 /** adds variable to SOS2 constraint, the position is determined by the given weight */ 127 SCIP_EXPORT 128 SCIP_RETCODE SCIPaddVarSOS2( 129 SCIP* scip, /**< SCIP data structure */ 130 SCIP_CONS* cons, /**< constraint */ 131 SCIP_VAR* var, /**< variable to add to the constraint */ 132 SCIP_Real weight /**< weight determining position of variable */ 133 ); 134 135 /** appends variable to SOS2 constraint */ 136 SCIP_EXPORT 137 SCIP_RETCODE SCIPappendVarSOS2( 138 SCIP* scip, /**< SCIP data structure */ 139 SCIP_CONS* cons, /**< constraint */ 140 SCIP_VAR* var /**< variable to add to the constraint */ 141 ); 142 143 /** gets number of variables in SOS2 constraint */ 144 SCIP_EXPORT 145 int SCIPgetNVarsSOS2( 146 SCIP* scip, /**< SCIP data structure */ 147 SCIP_CONS* cons /**< constraint */ 148 ); 149 150 /** gets array of variables in SOS2 constraint */ 151 SCIP_EXPORT 152 SCIP_VAR** SCIPgetVarsSOS2( 153 SCIP* scip, /**< SCIP data structure */ 154 SCIP_CONS* cons /**< constraint data */ 155 ); 156 157 /** gets array of weights in SOS2 constraint (or NULL if not existent) */ 158 SCIP_EXPORT 159 SCIP_Real* SCIPgetWeightsSOS2( 160 SCIP* scip, /**< SCIP data structure */ 161 SCIP_CONS* cons /**< constraint data */ 162 ); 163 164 /** @} */ 165 166 /** @} */ 167 168 #ifdef __cplusplus 169 } 170 #endif 171 172 #endif 173