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_xor.h 26 * @ingroup CONSHDLRS 27 * @brief Constraint handler for XOR constraints, \f$rhs = x_1 \oplus x_2 \oplus \dots \oplus x_n\f$ 28 * @author Tobias Achterberg 29 * @author Stefan Heinz 30 * @author Michael Winkler 31 * 32 */ 33 34 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 35 36 #ifndef __SCIP_CONS_XOR_H__ 37 #define __SCIP_CONS_XOR_H__ 38 39 40 #include "scip/def.h" 41 #include "scip/type_cons.h" 42 #include "scip/type_retcode.h" 43 #include "scip/type_scip.h" 44 #include "scip/type_var.h" 45 46 #ifdef __cplusplus 47 extern "C" { 48 #endif 49 50 /** creates the handler for xor constraints and includes it in SCIP 51 * 52 * @ingroup ConshdlrIncludes 53 * */ 54 SCIP_EXPORT 55 SCIP_RETCODE SCIPincludeConshdlrXor( 56 SCIP* scip /**< SCIP data structure */ 57 ); 58 59 /**@addtogroup CONSHDLRS 60 * 61 * @{ 62 * 63 * @name XOR Constraints 64 * 65 * @{ 66 * 67 * This constraint handler deals with "xor" constraint. These are constraint of the form: 68 * 69 * \f[ 70 * rhs = x_1 \oplus x_2 \oplus \dots \oplus x_n 71 * \f] 72 * 73 * where \f$x_i\f$ is a binary variable for all \f$i\f$ and \f$rhs\f$ is bool. The variables \f$x\f$'s are called 74 * operators. This constraint is satisfied if \f$rhs\f$ is TRUE and an odd number of the operators are TRUE or if the 75 * \f$rhs\f$ is FALSE and a even number of operators are TRUE. Hence, if the sum of \f$rhs\f$ and operators is even. 76 */ 77 78 /** creates and captures an xor constraint 79 * 80 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 81 */ 82 SCIP_EXPORT 83 SCIP_RETCODE SCIPcreateConsXor( 84 SCIP* scip, /**< SCIP data structure */ 85 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 86 const char* name, /**< name of constraint */ 87 SCIP_Bool rhs, /**< right hand side of the constraint */ 88 int nvars, /**< number of operator variables in the constraint */ 89 SCIP_VAR** vars, /**< array with operator variables of constraint */ 90 SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? 91 * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */ 92 SCIP_Bool separate, /**< should the constraint be separated during LP processing? 93 * Usually set to TRUE. */ 94 SCIP_Bool enforce, /**< should the constraint be enforced during node processing? 95 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 96 SCIP_Bool check, /**< should the constraint be checked for feasibility? 97 * TRUE for model constraints, FALSE for additional, redundant constraints. */ 98 SCIP_Bool propagate, /**< should the constraint be propagated during node processing? 99 * Usually set to TRUE. */ 100 SCIP_Bool local, /**< is constraint only valid locally? 101 * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */ 102 SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? 103 * Usually set to FALSE. In column generation applications, set to TRUE if pricing 104 * adds coefficients to this constraint. */ 105 SCIP_Bool dynamic, /**< is constraint subject to aging? 106 * Usually set to FALSE. Set to TRUE for own cuts which 107 * are separated as constraints. */ 108 SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? 109 * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */ 110 SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even 111 * if it may be moved to a more global node? 112 * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */ 113 ); 114 115 /** creates and captures an xor constraint 116 * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the 117 * method SCIPcreateConsXor(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h 118 * 119 * @see SCIPcreateConsXor() for information about the basic constraint flag configuration 120 * 121 * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons() 122 */ 123 SCIP_EXPORT 124 SCIP_RETCODE SCIPcreateConsBasicXor( 125 SCIP* scip, /**< SCIP data structure */ 126 SCIP_CONS** cons, /**< pointer to hold the created constraint */ 127 const char* name, /**< name of constraint */ 128 SCIP_Bool rhs, /**< right hand side of the constraint */ 129 int nvars, /**< number of operator variables in the constraint */ 130 SCIP_VAR** vars /**< array with operator variables of constraint */ 131 ); 132 133 /** gets number of variables in xor constraint */ 134 SCIP_EXPORT 135 int SCIPgetNVarsXor( 136 SCIP* scip, /**< SCIP data structure */ 137 SCIP_CONS* cons /**< constraint data */ 138 ); 139 140 /** gets array of variables in xor constraint */ 141 SCIP_EXPORT 142 SCIP_VAR** SCIPgetVarsXor( 143 SCIP* scip, /**< SCIP data structure */ 144 SCIP_CONS* cons /**< constraint data */ 145 ); 146 147 /** gets integer variable in xor constraint */ 148 SCIP_EXPORT 149 SCIP_VAR* SCIPgetIntVarXor( 150 SCIP* scip, /**< SCIP data structure */ 151 SCIP_CONS* cons /**< constraint data */ 152 ); 153 154 /** gets the right hand side of the xor constraint */ 155 SCIP_EXPORT 156 SCIP_Bool SCIPgetRhsXor( 157 SCIP* scip, /**< SCIP data structure */ 158 SCIP_CONS* cons /**< constraint data */ 159 ); 160 161 /** @} */ 162 163 /** @} */ 164 165 #ifdef __cplusplus 166 } 167 #endif 168 169 #endif 170