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 objbenderscut.h 26 * @brief C++ wrapper for Benders' decomposition cuts 27 * @author Stephen J. Maher 28 */ 29 30 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 31 32 #ifndef __SCIP_OBJBENDERSCUT_H__ 33 #define __SCIP_OBJBENDERSCUT_H__ 34 35 36 #include <cassert> 37 #include <cstring> 38 #include <utility> 39 40 #include "scip/scip.h" 41 #include "objscip/objcloneable.h" 42 #include "objscip/objbenders.h" 43 44 namespace scip 45 { 46 47 /** @brief C++ wrapper for Benders' decomposition cut 48 * 49 * This class defines the interface for the Benders' decomposition cuts implemented in C++. Note that there is 50 * a pure virtual function (this must be implemented). This function is: benderscut_exec(). 51 * 52 * - \ref BENDERSCUT "Instructions for implementing a Benders' decomposition plugin" 53 * - \ref BENDERSCUTS "List of available Benders' decomposition plugins" 54 * - \ref type_benderscut.h "Corresponding C interface" 55 */ 56 class ObjBenderscut : public ObjCloneable 57 { 58 public: 59 /*lint --e{1540}*/ 60 61 /** SCIP data structure */ 62 SCIP* scip_; 63 64 /** name of the Benders' decomposition cut */ 65 char* scip_name_; 66 67 /** description of the Benders' decomposition cut */ 68 char* scip_desc_; 69 70 /** the priority of the Benders' decomposition cut */ 71 const int scip_priority_; 72 73 /** is the Benders' decomposition cut generated from the LP relaxation of the subproblem */ 74 const SCIP_Bool scip_islpcut_; 75 76 /** default constructor */ 77 ObjBenderscut( 78 SCIP* scip, /**< SCIP data structure */ 79 const char* name, /**< name of Benders' decomposition */ 80 const char* desc, /**< description of Benders' decomposition */ 81 int priority, /**< priority of the Benders' decomposition */ 82 SCIP_Bool islpcut /**< is the cut generated from the LP relaxation */ 83 ) 84 : scip_(scip), 85 scip_name_(0), 86 scip_desc_(0), 87 scip_priority_(priority), 88 scip_islpcut_(islpcut) 89 { 90 /* the macro SCIPduplicateMemoryArray does not need the first argument: */ 91 SCIP_CALL_ABORT( SCIPduplicateMemoryArray(scip_, &scip_name_, name, std::strlen(name)+1) ); 92 SCIP_CALL_ABORT( SCIPduplicateMemoryArray(scip_, &scip_desc_, desc, std::strlen(desc)+1) ); 93 } 94 95 /** copy constructor */ 96 ObjBenderscut(const ObjBenderscut& o) 97 : ObjBenderscut(o.scip_, o.scip_name_, o.scip_desc_, o.scip_priority_, o.scip_islpcut_) 98 { 99 } 100 101 /** move constructor */ 102 ObjBenderscut(ObjBenderscut&& o) 103 : scip_(o.scip_), scip_name_(0), scip_desc_(0), scip_priority_(o.scip_priority_), scip_islpcut_(o.scip_islpcut_) 104 { 105 std::swap(scip_name_, o.scip_name_); 106 std::swap(scip_desc_, o.scip_desc_); 107 } 108 109 /** destructor */ 110 virtual ~ObjBenderscut() 111 { 112 /* the macro SCIPfreeMemoryArray does not need the first argument: */ 113 /*lint --e{64}*/ 114 SCIPfreeMemoryArray(scip_, &scip_name_); 115 SCIPfreeMemoryArray(scip_, &scip_desc_); 116 } 117 118 /** assignment of polymorphic classes causes slicing and is therefore disabled. */ 119 ObjBenderscut& operator=(const ObjBenderscut& o) = delete; 120 121 /** assignment of polymorphic classes causes slicing and is therefore disabled. */ 122 ObjBenderscut& operator=(ObjBenderscut&& o) = delete; 123 124 /** copy method for compression plugins (called when SCIP copies plugins) 125 * 126 * @see SCIP_DECL_BENDERSCUTCOPY(x) in @ref type_benders.h 127 */ 128 virtual SCIP_DECL_BENDERSCUTCOPY(scip_copy) 129 { /*lint --e{715}*/ 130 return SCIP_OKAY; 131 } 132 133 /** destructor of Benders' decomposition cuts to free user data (called when SCIP is exiting) 134 * 135 * @see SCIP_DECL_BENDERSCUTFREE(x) in @ref type_benders.h 136 */ 137 virtual SCIP_DECL_BENDERSCUTFREE(scip_free) 138 { /*lint --e{715}*/ 139 return SCIP_OKAY; 140 } 141 142 /** initialization method of Benders' decomposition cuts (called after problem was transformed) 143 * 144 * @see SCIP_DECL_BENDERSCUTINIT(x) in @ref type_benders.h 145 */ 146 virtual SCIP_DECL_BENDERSCUTINIT(scip_init) 147 { /*lint --e{715}*/ 148 return SCIP_OKAY; 149 } 150 151 /** deinitialization method of Benders' decomposition cuts (called before transformed problem is freed) 152 * 153 * @see SCIP_DECL_BENDERSCUTEXIT(x) in @ref type_benders.h 154 */ 155 virtual SCIP_DECL_BENDERSCUTEXIT(scip_exit) 156 { /*lint --e{715}*/ 157 return SCIP_OKAY; 158 } 159 160 /** solving process initialization method of Benders' decomposition cuts (called when branch and bound process is about to begin) 161 * 162 * @see SCIP_DECL_BENDERSCUTINITSOL(x) in @ref type_benders.h 163 */ 164 virtual SCIP_DECL_BENDERSCUTINITSOL(scip_initsol) 165 { /*lint --e{715}*/ 166 return SCIP_OKAY; 167 } 168 169 /** solving process deinitialization method of Benders' decomposition cuts (called before branch and bound process data is freed) 170 * 171 * This method is called before the branch and bound process is freed. 172 * The Benders' decomposition cuts should use this call to clean up its branch and bound data. 173 * 174 * @see SCIP_DECL_BENDERSCUTEXITSOL(x) in @ref type_benders.h 175 */ 176 virtual SCIP_DECL_BENDERSCUTEXITSOL(scip_exitsol) 177 { /*lint --e{715}*/ 178 return SCIP_OKAY; 179 } 180 181 /** execution method of Benders' decomposition cuts technique 182 * 183 * @see SCIP_DECL_BENDERSCUTEXEC(x) in @ref type_benders.h 184 */ 185 virtual SCIP_DECL_BENDERSCUTEXEC(scip_exec) = 0; 186 }; 187 188 } /* namespace scip */ 189 190 191 192 /** creates the Benders' decomposition cut for the given Benders' decomposition cut object and includes it in SCIP 193 * 194 * The method should be called in one of the following ways: 195 * 196 * 1. The user is responsible for deleting the object: 197 * SCIP_CALL( SCIPcreate(&scip) ); 198 * ... 199 * MyBenderscut* mybenderscut = new MyBenderscut(...); 200 * SCIP_CALL( SCIPincludeObjBenderscut(scip, benders, &mybenderscut, FALSE) ); 201 * ... 202 * SCIP_CALL( SCIPfree(&scip) ); 203 * delete mybenderscut; // delete benderscut AFTER SCIPfree() ! 204 * 205 * 2. The object pointer is passed to SCIP and deleted by SCIP in the SCIPfree() call: 206 * SCIP_CALL( SCIPcreate(&scip) ); 207 * ... 208 * SCIP_CALL( SCIPincludeObjBenderscut(scip, benders, new MyBenderscut(...), TRUE) ); 209 * ... 210 * SCIP_CALL( SCIPfree(&scip) ); // destructor of MyBenderscut is called here 211 */ 212 SCIP_EXPORT 213 SCIP_RETCODE SCIPincludeObjBenderscut( 214 SCIP* scip, /**< SCIP data structure */ 215 scip::ObjBenders* objbenders, /**< Benders' decomposition object */ 216 scip::ObjBenderscut* objbenderscut, /**< Benders' decomposition cut object */ 217 SCIP_Bool deleteobject /**< should the Benders' cut object be deleted when benderscut is freed? */ 218 ); 219 220 /** returns the benderscut object of the given name, or 0 if not existing */ 221 SCIP_EXPORT 222 scip::ObjBenderscut* SCIPfindObjBenderscut( 223 scip::ObjBenders* objbenders, /**< Benders' decomposition object */ 224 const char* name /**< name of Benders' decomposition cut */ 225 ); 226 227 /** returns the benderscut object for the given constraint handler */ 228 SCIP_EXPORT 229 scip::ObjBenderscut* SCIPgetObjBenderscut( 230 SCIP* scip, /**< SCIP data structure */ 231 SCIP_BENDERSCUT* benderscut /**< Benders' decomposition cut */ 232 ); 233 234 #endif 235