/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright 2002-2022 Zuse Institute Berlin */ /* */ /* Licensed under the Apache License, Version 2.0 (the "License"); */ /* you may not use this file except in compliance with the License. */ /* You may obtain a copy of the License at */ /* */ /* http://www.apache.org/licenses/LICENSE-2.0 */ /* */ /* Unless required by applicable law or agreed to in writing, software */ /* distributed under the License is distributed on an "AS IS" BASIS, */ /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ /* See the License for the specific language governing permissions and */ /* limitations under the License. */ /* */ /* You should have received a copy of the Apache-2.0 license */ /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file type_conflict.h * @ingroup TYPEDEFINITIONS * @brief type definitions for conflict analysis * @author Tobias Achterberg * * This file defines the interface for conflict handler implemented in C. * */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_TYPE_CONFLICT_H__ #define __SCIP_TYPE_CONFLICT_H__ #include "scip/def.h" #include "scip/type_retcode.h" #include "scip/type_result.h" #include "scip/type_var.h" #ifdef __cplusplus extern "C" { #endif typedef struct SCIP_Conflicthdlr SCIP_CONFLICTHDLR; /**< conflict handler to process conflict sets */ typedef struct SCIP_ConflicthdlrData SCIP_CONFLICTHDLRDATA; /**< conflict handler data */ typedef struct SCIP_ConflictSet SCIP_CONFLICTSET; /**< set of conflicting bound changes */ typedef struct SCIP_ProofSet SCIP_PROOFSET; /**< set of variables and coefficients describing a proof-constraint of type a^Tx <= rhs */ typedef struct SCIP_LPBdChgs SCIP_LPBDCHGS; /**< set of LP bound changes */ typedef struct SCIP_Conflict SCIP_CONFLICT; /**< conflict analysis data structure */ /** types of conflicts */ enum SCIP_ConflictType { SCIP_CONFTYPE_UNKNOWN = 0, /**< unknown type */ SCIP_CONFTYPE_PROPAGATION = 1, /**< conflict results from propagation */ SCIP_CONFTYPE_INFEASLP = 2, /**< conflict results from an infeasible LP relaxation */ SCIP_CONFTYPE_BNDEXCEEDING = 3, /**< conflict results from a boundexceeding LP relaxation */ SCIP_CONFTYPE_ALTINFPROOF = 4, /**< alternative proof of an infeasible LP relaxation */ SCIP_CONFTYPE_ALTBNDPROOF = 5 /**< alternative proof of a boundexceeding LP relaxation */ }; typedef enum SCIP_ConflictType SCIP_CONFTYPE; /** dualray presolving strategy */ enum SCIP_ConflictPresolStrat { SCIP_CONFPRES_DISABLED = 0, /**< no presolving */ SCIP_CONFPRES_ONLYLOCAL = 1, /**< keep variables contributing with its local bound */ SCIP_CONFPRES_ONLYGLOBAL = 2, /**< keep variables contributing with its global bound */ SCIP_CONFPRES_BOTH = 3 /**< keep variables contributing with its global bound and add a few * variables contributing with its local bound such that the * constraint is not globally redundant */ }; typedef enum SCIP_ConflictPresolStrat SCIP_CONFPRES; /** copy method for conflict handler plugins (called when SCIP copies plugins) * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** destructor of conflict handler to free conflict handler data (called when SCIP is exiting) * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTFREE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** initialization method of conflict handler (called after problem was transformed) * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTINIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** deinitialization method of conflict handler (called before transformed problem is freed) * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTEXIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** solving process initialization method of conflict handler (called when branch and bound process is about to begin) * * This method is called when the presolving was finished and the branch and bound process is about to begin. * The conflict handler may use this call to initialize its branch and bound specific data. * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTINITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** solving process deinitialization method of conflict handler (called before branch and bound process data is freed) * * This method is called before the branch and bound process is freed. * The conflict handler should use this call to clean up its branch and bound data. * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself */ #define SCIP_DECL_CONFLICTEXITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr) /** conflict processing method of conflict handler (called when conflict was found) * * This method is called, when the conflict analysis found a conflict on variable bounds. * The conflict handler may update its data accordingly and create a constraint out of the conflict set. * If the parameter "resolved" is set, the conflict handler should not create a constraint, because * a different conflict handler with higher priority already created a constraint. * The bounds in the conflict set lead to a conflict (i.e. an infeasibility) when all enforced at the same time. * Thus, a feasible conflict constraint must demand that at least one of the variables in the conflict * set violates its corresponding bound, i.e., fulfills the negation of the bound change in the conflict set. * For continuous variables, the negation has to be defined in a relaxed way: if, e.g., the bound in the conflict * set is "x <= u", the negation to be used has to be "x >= u", and not "x > u". * The given "bdchginfos" array representing the conflict set is only a reference to an internal * buffer, that may be modified at any time by SCIP. The user must copy the needed information from the * "bdchginfos" array to own data structures, if (s)he wants to use the information later. * (S)he should not keep a pointer to the array or pointers to the single bdchginfos in the array, because these * may get invalid afterwards. * * input: * - scip : SCIP main data structure * - conflicthdlr : the conflict handler itself * - node : node to add resulting conflict constraint to (with SCIPaddConsNode()) * - validnode : node at which the conflict constraint is valid (should be passed to SCIPaddConsNode()) * - bdchginfos : array with bound changes that lead to a conflict * - relaxedbds : array with relaxed bounds which are efficient to create a valid conflict * - nbdchginfos : number of bound changes in the conflict set * -.primalbound : the current primal bound, or -infininity if the conflict arises from an infeasible LP * - separate : should the conflict constraint be separated? * - local : is the conflict set only valid locally, i.e., should the constraint be created as local constraint? * - dynamic : should the conflict constraint be made subject to aging? * - removable : should the conflict's relaxation be made subject to LP aging and cleanup? * - resolved : is the conflict set already used to create a constraint? * - result : pointer to store the result of the conflict processing call * * possible return values for *result: * - SCIP_CONSADDED : the conflict handler created a constraint out of the conflict set * - SCIP_DIDNOTFIND : the conflict handler could not create a constraint out of the conflict set * - SCIP_DIDNOTRUN : the conflict handler was skipped */ #define SCIP_DECL_CONFLICTEXEC(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr, SCIP_NODE* node, \ SCIP_NODE* validnode, SCIP_BDCHGINFO** bdchginfos, SCIP_Real* relaxedbds, int nbdchginfos, SCIP_CONFTYPE conftype, \ SCIP_Bool cutoffinvolved, SCIP_Bool separate, SCIP_Bool local, SCIP_Bool dynamic, SCIP_Bool removable, \ SCIP_Bool resolved, SCIP_RESULT* result) #ifdef __cplusplus } #endif #endif