1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (C) 2002-2021 Konrad-Zuse-Zentrum */ 7 /* fuer Informationstechnik Berlin */ 8 /* */ 9 /* SCIP is distributed under the terms of the ZIB Academic License. */ 10 /* */ 11 /* You should have received a copy of the ZIB Academic License */ 12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */ 13 /* */ 14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 15 16 /**@file cons_logicor.h 17 * @ingroup CONSHDLRS 18 * @brief Constraint handler for logicor constraints \f$1^T x \ge 1\f$ (equivalent to set covering, but algorithms are suited for depth first search). 19 * @author Tobias Achterberg 20 * @author Michael Winkler 21 * 22 */ 23 24 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 25 26 #ifndef __SCIP_CONS_LOGICOR_H__ 27 #define __SCIP_CONS_LOGICOR_H__ 28 29 30 #include "scip/def.h" 31 #include "scip/type_cons.h" 32 #include "scip/type_lp.h" 33 #include "scip/type_retcode.h" 34 #include "scip/type_scip.h" 35 #include "scip/type_var.h" 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 /** creates the handler for logic or constraints and includes it in SCIP 42 * 43 * @ingroup ConshdlrIncludes 44 * */ 45 SCIP_EXPORT 46 SCIP_RETCODE SCIPincludeConshdlrLogicor( 47 SCIP* scip /**< SCIP data structure */ 48 ); 49 50 /**@addtogroup CONSHDLRS 51 * 52 * @{ 53 * 54 * @name Logicor Constraints 55 * 56 * @{ 57 * 58 * This constraint handler handles a special type of linear constraints, namely 59 * logic or constraints. These are equivalent to set covering constraints, but 60 * are handled by special algorithms which are better suited for depth first search. 61 * For a set of binary variables \f$x_i, i=1,\dots,n\f$, a logic or constraint has the form 62 * \f[ 63 * \sum_{i=1}^n x_i \ge 1. 64 * \f] 65 */ 66 67 /** creates and captures a logic or constraint 68 * 69 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 70 */ 71 SCIP_EXPORT 72 SCIP_RETCODE SCIPcreateConsLogicor( 73 SCIP* scip, /**< SCIP data structure */ 74 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 75 const char* name, /**< name of constraint */ 76 int nvars, /**< number of variables in the constraint */ 77 SCIP_VAR** vars, /**< array with variables of constraint entries */ 78 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? 79 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ 80 SCIP_Bool separate, /**< should the constraint be separated during LP processing? 81 * Usually set to TRUE. */ 82 SCIP_Bool enforce, /**< should the constraint be enforced during node processing? 83 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 84 SCIP_Bool check, /**< should the constraint be checked for feasibility? 85 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 86 SCIP_Bool propagate, /**< should the constraint be propagated during node processing? 87 * Usually set to TRUE. */ 88 SCIP_Bool local, /**< is constraint only valid locally? 89 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ 90 SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? 91 * Usually set to FALSE. In column generation applications, set to TRUE if pricing 92 * adds coefficients to this constraint. */ 93 SCIP_Bool dynamic, /**< is constraint subject to aging? 94 * Usually set to FALSE. Set to TRUE for own cuts which 95 * are separated as constraints. */ 96 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? 97 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ 98 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even 99 * if it may be moved to a more global node? 100 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ 101 ); 102 103 /** creates and captures a logicor constraint 104 * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the 105 * method SCIPcreateConsLogicor(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h 106 * 107 * @see SCIPcreateConsLogicor() for information about the basic constraint flag configuration 108 * 109 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 110 */ 111 SCIP_EXPORT 112 SCIP_RETCODE SCIPcreateConsBasicLogicor( 113 SCIP* scip, /**< SCIP data structure */ 114 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 115 const char* name, /**< name of constraint */ 116 int nvars, /**< number of variables in the constraint */ 117 SCIP_VAR** vars /**< array with variables of constraint entries */ 118 ); 119 120 /** adds coefficient in logic or constraint */ 121 SCIP_EXPORT 122 SCIP_RETCODE SCIPaddCoefLogicor( 123 SCIP* scip, /**< SCIP data structure */ 124 SCIP_CONS* cons, /**< logicor constraint */ 125 SCIP_VAR* var /**< variable to add to the constraint */ 126 ); 127 128 /** gets number of variables in logic or constraint */ 129 SCIP_EXPORT 130 int SCIPgetNVarsLogicor( 131 SCIP* scip, /**< SCIP data structure */ 132 SCIP_CONS* cons /**< constraint data */ 133 ); 134 135 /** gets array of variables in logic or constraint */ 136 SCIP_EXPORT 137 SCIP_VAR** SCIPgetVarsLogicor( 138 SCIP* scip, /**< SCIP data structure */ 139 SCIP_CONS* cons /**< constraint data */ 140 ); 141 142 /** gets the dual solution of the logic or constraint in the current LP */ 143 SCIP_EXPORT 144 SCIP_Real SCIPgetDualsolLogicor( 145 SCIP* scip, /**< SCIP data structure */ 146 SCIP_CONS* cons /**< constraint data */ 147 ); 148 149 /** gets the dual Farkas value of the logic or constraint in the current infeasible LP */ 150 SCIP_EXPORT 151 SCIP_Real SCIPgetDualfarkasLogicor( 152 SCIP* scip, /**< SCIP data structure */ 153 SCIP_CONS* cons /**< constraint data */ 154 ); 155 156 /** returns the linear relaxation of the given logic or constraint; may return NULL if no LP row was yet created; 157 * the user must not modify the row! 158 */ 159 SCIP_EXPORT 160 SCIP_ROW* SCIPgetRowLogicor( 161 SCIP* scip, /**< SCIP data structure */ 162 SCIP_CONS* cons /**< constraint data */ 163 ); 164 165 /** cleans up (multi-)aggregations and fixings from logicor constraints */ 166 SCIP_EXPORT 167 SCIP_RETCODE SCIPcleanupConssLogicor( 168 SCIP* scip, /**< SCIP data structure */ 169 SCIP_Bool onlychecked, /**< should only checked constraints be cleaned up? */ 170 int* naddconss, /**< pointer to count number of added (linear) constraints */ 171 int* ndelconss, /**< pointer to count number of deleted (logicor) constraints */ 172 int* nchgcoefs /**< pointer to count number of changed coefficients */ 173 ); 174 175 /** @} */ 176 177 /** @} */ 178 179 #ifdef __cplusplus 180 } 181 #endif 182 183 #endif 184