/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* 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_cons.h * @ingroup TYPEDEFINITIONS * @brief type definitions for constraints and constraint handlers * @author Tobias Achterberg * @author Stefan Heinz * * This file defines the interface for constraint handlers implemented in C. * * - \ref CONS "Instructions for implementing a constraint handler" * - \ref CONSHDLRS "List of available constraint handlers" * - \ref scip::ObjConshdlr "C++ wrapper class" */ /** @defgroup DEFPLUGINS_CONS Default constraint handlers * @ingroup DEFPLUGINS * @brief implementation files (.c files) of the default constraint handlers of SCIP */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_TYPE_CONS_H__ #define __SCIP_TYPE_CONS_H__ #include "scip/def.h" #include "scip/type_lp.h" #include "scip/type_retcode.h" #include "scip/type_result.h" #include "scip/type_var.h" #include "scip/type_sol.h" #include "scip/type_scip.h" #include "scip/type_timing.h" #include "scip/type_heur.h" #ifdef __cplusplus extern "C" { #endif typedef struct SCIP_Conshdlr SCIP_CONSHDLR; /**< constraint handler for a specific constraint type */ typedef struct SCIP_Cons SCIP_CONS; /**< constraint data structure */ typedef struct SCIP_ConshdlrData SCIP_CONSHDLRDATA; /**< constraint handler data */ typedef struct SCIP_ConsData SCIP_CONSDATA; /**< locally defined constraint type specific data */ typedef struct SCIP_ConsSetChg SCIP_CONSSETCHG; /**< tracks additions and removals of the set of active constraints */ typedef struct SCIP_LinConsStats SCIP_LINCONSSTATS; /**< linear constraint classification statistics used for MIPLIB */ /** linear constraint types recognizable */ enum SCIP_LinConstype { SCIP_LINCONSTYPE_EMPTY = 0, /**< linear constraints with no variables */ SCIP_LINCONSTYPE_FREE = 1, /**< linear constraints with no finite side */ SCIP_LINCONSTYPE_SINGLETON = 2, /**< linear constraints with a single variable */ SCIP_LINCONSTYPE_AGGREGATION = 3, /**< linear constraints of the type \f$ ax + by = c\f$ */ SCIP_LINCONSTYPE_PRECEDENCE = 4, /**< linear constraints of the type \f$ a x - a y \leq b\f$ where \f$x\f$ and \f$y\f$ must have the same type */ SCIP_LINCONSTYPE_VARBOUND = 5, /**< linear constraints of the form \f$ ax + by \leq c \, x \in \{0,1\} \f$ */ SCIP_LINCONSTYPE_SETPARTITION = 6, /**< linear constraints of the form \f$ \sum x_i = 1\, x_i \in \{0,1\} \forall i \f$ */ SCIP_LINCONSTYPE_SETPACKING = 7, /**< linear constraints of the form \f$ \sum x_i \leq 1\, x_i \in \{0,1\} \forall i \f$ */ SCIP_LINCONSTYPE_SETCOVERING = 8, /**< linear constraints of the form \f$ \sum x_i \geq 1\, x_i \in \{0,1\} \forall i \f$ */ SCIP_LINCONSTYPE_CARDINALITY = 9, /**< linear constraints of the form \f$ \sum x_i = k\, x_i \in \{0,1\} \forall i, \, k\geq 2 \f$ */ SCIP_LINCONSTYPE_INVKNAPSACK = 10, /**< linear constraints of the form \f$ \sum x_i \leq b\, x_i \in \{0,1\} \forall i, \, b\in \mathbb{n} \geq 2 \f$ */ SCIP_LINCONSTYPE_EQKNAPSACK = 11, /**< linear constraints of the form \f$ \sum a_i x_i = b\, x_i \in \{0,1\} \forall i, \, b\in \mathbb{n} \geq 2 \f$ */ SCIP_LINCONSTYPE_BINPACKING = 12, /**< linear constraints of the form \f$ \sum a_i x_i + a x \leq a\, x, x_i \in \{0,1\} \forall i, \, a\in \mathbb{n} \geq 2 \f$ */ SCIP_LINCONSTYPE_KNAPSACK = 13, /**< linear constraints of the form \f$ \sum a_k x_k \leq b\, x_i \in \{0,1\} \forall i, \, b\in \mathbb{n} \geq 2 \f$ */ SCIP_LINCONSTYPE_INTKNAPSACK = 14, /**< linear constraints of the form \f$ \sum a_k x_k \leq b\, x_i \in \mathbb{Z} \forall i, \, b\in \mathbb{n} \f$ */ SCIP_LINCONSTYPE_MIXEDBINARY = 15, /**< linear constraints of the form \f$ \sum a_k x_k + \sum p_j s_j \leq/= b\, x_i \in \{0,1\} \forall i, s_j \in \text{ cont. } \forall j\f$ */ SCIP_LINCONSTYPE_GENERAL = 16 /**< general linear constraints with no special structure */ }; typedef enum SCIP_LinConstype SCIP_LINCONSTYPE; #define SCIP_NLINCONSTYPES ((int)SCIP_LINCONSTYPE_GENERAL+1) /** copy method for constraint handler plugins (called when SCIP copies plugins) * * If the copy process was one to one, the valid pointer can be set to TRUE. Otherwise, this pointer has to be set to * FALSE. If all problem defining objects (constraint handlers and variable pricers) return valid = TRUE for all * their copying calls, SCIP assumes that it is an overall one to one copy of the original instance. In this case any * reductions made in the copied SCIP instance can be transfered to the original SCIP instance. If the valid pointer is * set to TRUE and it was not a one to one copy, it might happen that optimal solutions are cut off. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - valid : was the copying process valid? */ #define SCIP_DECL_CONSHDLRCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_Bool* valid) /** destructor of constraint handler to free constraint handler data (called when SCIP is exiting) * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself */ #define SCIP_DECL_CONSFREE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr) /** initialization method of constraint handler (called after problem was transformed) * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints in transformed problem * - nconss : number of constraints in transformed problem */ #define SCIP_DECL_CONSINIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** deinitialization method of constraint handler (called before transformed problem is freed) * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints in transformed problem * - nconss : number of constraints in transformed problem */ #define SCIP_DECL_CONSEXIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** presolving initialization method of constraint handler (called when presolving is about to begin) * * This method is called when the presolving process is about to begin, even if presolving is turned off. * The constraint handler may use this call to initialize its data structures. * * Necessary modifications that have to be performed even if presolving is turned off should be done here or in the * presolving deinitialization call (SCIP_DECL_CONSEXITPRE()). * * @note Note that the constraint array might contain constraints that were created but not added to the problem. * Constraints that are not added, i.e., for which SCIPconsIsAdded() returns FALSE, cannot be used for problem * reductions. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints in transformed problem * - nconss : number of constraints in transformed problem */ #define SCIP_DECL_CONSINITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** presolving deinitialization method of constraint handler (called after presolving has been finished) * * This method is called after the presolving has been finished, even if presolving is turned off. * The constraint handler may use this call e.g. to clean up or modify its data structures. * * Necessary modifications that have to be performed even if presolving is turned off should be done here or in the * presolving initialization call (SCIP_DECL_CONSINITPRE()). * * Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the * problem has already been solved. Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL, * SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD. * * @note Note that the constraint array might contain constraints that were created but not added to the problem. * Constraints that are not added, i.e., for which SCIPconsIsAdded() returns FALSE, cannot be used for problem * reductions. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : final array of constraints in transformed problem * - nconss : final number of constraints in transformed problem */ #define SCIP_DECL_CONSEXITPRE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** solving process initialization method of constraint 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 constraint handler may use this call to initialize its branch and bound specific data. * * Besides necessary modifications and clean up, no time consuming operations should be performed, especially if the * problem has already been solved. Use the method SCIPgetStatus(), which in this case returns SCIP_STATUS_OPTIMAL, * SCIP_STATUS_INFEASIBLE, SCIP_STATUS_UNBOUNDED, or SCIP_STATUS_INFORUNBD. * * @note Note that the constraint array might contain constraints that were created but not added to the problem. * Constraints that are not added, i.e., for which SCIPconsIsAdded() returns FALSE, cannot be used for problem * reductions. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints of the constraint handler * - nconss : number of constraints of the constraint handler */ #define SCIP_DECL_CONSINITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** solving process deinitialization method of constraint handler (called before branch and bound process data is freed) * * This method is called before the branch and bound process is freed. * The constraint handler should use this call to clean up its branch and bound data, in particular to release * all LP rows that he has created or captured. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints of the constraint handler * - nconss : number of constraints of the constraint handler * - restart : was this exit solve call triggered by a restart? */ #define SCIP_DECL_CONSEXITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, SCIP_Bool restart) /** frees specific constraint data * * @warning There may exist unprocessed events. For example, a variable's bound may have been already changed, but the * corresponding bound change event was not yet processed. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint belonging to the constraint data * - consdata : pointer to the constraint data to free */ #define SCIP_DECL_CONSDELETE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, SCIP_CONSDATA** consdata) /** transforms constraint data into data belonging to the transformed problem * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - sourcecons : source constraint to transform * - targetcons : pointer to store created target constraint */ #define SCIP_DECL_CONSTRANS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* sourcecons, SCIP_CONS** targetcons) /** LP initialization method of constraint handler (called before the initial LP relaxation at a node is solved) * * Puts the LP relaxations of all "initial" constraints into the LP. The method should put a canonic LP relaxation * of all given constraints to the LP with calls to SCIPaddRow(). * * @warning It is not guaranteed that the problem is going to be declared infeasible if the infeasible pointer is set * to TRUE. Therefore, it is recommended that users do not end this method prematurely when an infeasiblity * is detected. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * * output: * - infeasible : pointer to store whether an infeasibility was detected while building the LP */ #define SCIP_DECL_CONSINITLP(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, SCIP_Bool* infeasible) /** separation method of constraint handler for LP solution * * Separates all constraints of the constraint handler. The method is called in the LP solution loop, * which means that a valid LP solution exists. * * The first nusefulconss constraints are the ones, that are identified to likely be violated. The separation * method should process only the useful constraints in most runs, and only occasionally the remaining * nconss - nusefulconss constraints. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - result : pointer to store the result of the separation call * * possible return values for *result (if more than one applies, the first in the list should be used): * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_CONSADDED : an additional constraint was generated * - SCIP_REDUCEDDOM : a variable's domain was reduced * - SCIP_SEPARATED : a cutting plane was generated * - SCIP_NEWROUND : a cutting plane was generated and a new separation round should immediately start * - SCIP_DIDNOTFIND : the separator searched, but did not find domain reductions, cutting planes, or cut constraints * - SCIP_DIDNOTRUN : the separator was skipped * - SCIP_DELAYED : the separator was skipped, but should be called again */ #define SCIP_DECL_CONSSEPALP(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, \ int nconss, int nusefulconss, SCIP_RESULT* result) /** separation method of constraint handler for arbitrary primal solution * * Separates all constraints of the constraint handler. The method is called outside the LP solution loop (e.g., by * a relaxator or a primal heuristic), which means that there is no valid LP solution. * Instead, the method should produce cuts that separate the given solution. * * The first nusefulconss constraints are the ones, that are identified to likely be violated. The separation * method should process only the useful constraints in most runs, and only occasionally the remaining * nconss - nusefulconss constraints. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - sol : primal solution that should be separated * - result : pointer to store the result of the separation call * * possible return values for *result (if more than one applies, the first in the list should be used): * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_CONSADDED : an additional constraint was generated * - SCIP_REDUCEDDOM : a variable's domain was reduced * - SCIP_SEPARATED : a cutting plane was generated * - SCIP_NEWROUND : a cutting plane was generated and a new separation round should immediately start * - SCIP_DIDNOTFIND : the separator searched, but did not find domain reductions, cutting planes, or cut constraints * - SCIP_DIDNOTRUN : the separator was skipped * - SCIP_DELAYED : the separator was skipped, but should be called again */ #define SCIP_DECL_CONSSEPASOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, \ int nconss, int nusefulconss, SCIP_SOL* sol, SCIP_RESULT* result) /** constraint enforcing method of constraint handler for LP solutions * * The method is called at the end of the node processing loop for a node where the LP was solved. * The LP solution has to be checked for feasibility. If possible, an infeasibility should be resolved by * branching, reducing a variable's domain to exclude the solution or separating the solution with a valid * cutting plane. * * The enforcing methods of the active constraint handlers are called in decreasing order of their enforcing * priorities until the first constraint handler returned with the value SCIP_CUTOFF, SCIP_SEPARATED, * SCIP_REDUCEDDOM, SCIP_CONSADDED, or SCIP_BRANCHED. * The integrality constraint handler has an enforcing priority of zero. A constraint handler which can * (or wants) to enforce its constraints only for integral solutions should have a negative enforcing priority * (e.g. the alldiff-constraint can only operate on integral solutions). * A constraint handler which wants to incorporate its own branching strategy even on non-integral * solutions must have an enforcing priority greater than zero (e.g. the SOS-constraint incorporates * SOS-branching on non-integral solutions). * * The first nusefulconss constraints are the ones, that are identified to likely be violated. The enforcing * method should process the useful constraints first. The other nconss - nusefulconss constraints should only * be enforced, if no violation was found in the useful constraints. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - solinfeasible : was the solution already declared infeasible by a constraint handler? * - result : pointer to store the result of the enforcing call * * possible return values for *result (if more than one applies, the first in the list should be used): * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_CONSADDED : an additional constraint was generated (added constraints must have initial flag = TRUE) * - SCIP_REDUCEDDOM : a variable's domain was reduced * - SCIP_SEPARATED : a cutting plane was generated * - SCIP_SOLVELP : the LP should be solved again because the LP primal feasibility tolerance has been tightened * - SCIP_BRANCHED : no changes were made to the problem, but a branching was applied to resolve an infeasibility * - SCIP_INFEASIBLE : at least one constraint is infeasible, but it was not resolved * - SCIP_FEASIBLE : all constraints of the handler are feasible */ #define SCIP_DECL_CONSENFOLP(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, int nusefulconss, \ SCIP_Bool solinfeasible, SCIP_RESULT* result) /** constraint enforcing method of constraint handler for relaxation solutions * * input: * - scip : SCIP main data structure * - sol : relaxation solution * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - solinfeasible : was the solution already declared infeasible by a constraint handler? * - result : pointer to store the result of the enforcing call * * possible return values for *result (if more than one applies, the first in the list should be used): * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_CONSADDED : an additional constraint was generated (added constraints must have initial flag = TRUE) * - SCIP_REDUCEDDOM : a variable's domain was reduced * - SCIP_SEPARATED : a cutting plane was generated * - SCIP_BRANCHED : no changes were made to the problem, but a branching was applied to resolve an infeasibility * - SCIP_SOLVELP : at least one constraint is infeasible, and this can only be resolved by solving the LP * - SCIP_INFEASIBLE : at least one constraint is infeasible, but it was not resolved * - SCIP_FEASIBLE : all constraints of the handler are feasible */ #define SCIP_DECL_CONSENFORELAX(x) SCIP_RETCODE x (SCIP* scip, SCIP_SOL* sol, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, int nusefulconss, \ SCIP_Bool solinfeasible, SCIP_RESULT* result) /** constraint enforcing method of constraint handler for pseudo solutions * * The method is called at the end of the node processing loop for a node where the LP was not solved. * The pseudo solution has to be checked for feasibility. If possible, an infeasibility should be resolved by * branching, reducing a variable's domain to exclude the solution or adding an additional constraint. * Separation is not possible, since the LP is not processed at the current node. All LP informations like * LP solution, slack values, or reduced costs are invalid and must not be accessed. * * Like in the enforcing method for LP solutions, the enforcing methods of the active constraint handlers are * called in decreasing order of their enforcing priorities until the first constraint handler returned with * the value SCIP_CUTOFF, SCIP_REDUCEDDOM, SCIP_CONSADDED, SCIP_BRANCHED, or SCIP_SOLVELP. * * The first nusefulconss constraints are the ones, that are identified to likely be violated. The enforcing * method should process the useful constraints first. The other nconss - nusefulconss constraints should only * be enforced, if no violation was found in the useful constraints. * * If the pseudo solution's objective value is lower than the lower bound of the node, it cannot be feasible * and the enforcing method may skip it's check and set *result to SCIP_DIDNOTRUN. However, it can also process * its constraints and return any other possible result code. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - solinfeasible : was the solution already declared infeasible by a constraint handler? * - objinfeasible : is the solution infeasible anyway due to violating lower objective bound? * - result : pointer to store the result of the enforcing call * * possible return values for *result (if more than one applies, the first in the list should be used): * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_CONSADDED : an additional constraint was generated * - SCIP_REDUCEDDOM : a variable's domain was reduced * - SCIP_BRANCHED : no changes were made to the problem, but a branching was applied to resolve an infeasibility * - SCIP_SOLVELP : at least one constraint is infeasible, and this can only be resolved by solving the LP * - SCIP_INFEASIBLE : at least one constraint is infeasible, but it was not resolved * - SCIP_FEASIBLE : all constraints of the handler are feasible * - SCIP_DIDNOTRUN : the enforcement was skipped (only possible, if objinfeasible is true) */ #define SCIP_DECL_CONSENFOPS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, int nusefulconss, \ SCIP_Bool solinfeasible, SCIP_Bool objinfeasible, SCIP_RESULT* result) /** feasibility check method of constraint handler for integral solutions * * The given solution has to be checked for feasibility. * * The check methods of the active constraint handlers are called in decreasing order of their check * priorities until the first constraint handler returned with the result SCIP_INFEASIBLE. * The integrality constraint handler has a check priority of zero. A constraint handler which can * (or wants) to check its constraints only for integral solutions should have a negative check priority * (e.g. the alldiff-constraint can only operate on integral solutions). * A constraint handler which wants to check feasibility even on non-integral solutions must have a * check priority greater than zero (e.g. if the check is much faster than testing all variables for * integrality). * * In some cases, integrality conditions or rows of the current LP don't have to be checked, because their * feasibility is already checked or implicitly given. In these cases, 'checkintegrality' or * 'checklprows' is FALSE. * * If the solution is not NULL, SCIP should also be informed about the constraint violation with a call to * SCIPupdateSolConsViolation() and additionally SCIPupdateSolLPRowViolation() for every row of the constraint's current * representation in the LP relaxation, if any such rows exist. * As a convenience method, SCIPupdateSolLPConsViolation() can be used if the constraint * is represented completely by a set of LP rows, meaning that the current constraint violation is equal to the maximum * of the contraint violations of the corresponding LP rows. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - sol : the solution to check feasibility for * - checkintegrality: Has integrality to be checked? * - checklprows : Do constraints represented by rows in the current LP have to be checked? * - printreason : Should the reason for the violation be printed? * - completely : Should all violations be checked? * - result : pointer to store the result of the feasibility checking call * * possible return values for *result: * - SCIP_INFEASIBLE : at least one constraint of the handler is infeasible * - SCIP_FEASIBLE : all constraints of the handler are feasible */ #define SCIP_DECL_CONSCHECK(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, SCIP_SOL* sol, \ SCIP_Bool checkintegrality, SCIP_Bool checklprows, SCIP_Bool printreason, SCIP_Bool completely, SCIP_RESULT* result) /** domain propagation method of constraint handler * * The first nusefulconss constraints are the ones, that are identified to likely be violated. The propagation * method should process only the useful constraints in most runs, and only occasionally the remaining * nconss - nusefulconss constraints. * * @note if the constraint handler uses dual information in propagation it is nesassary to check via calling * SCIPallowWeakDualReds and SCIPallowStrongDualReds if dual reductions and propgation with the current cutoff bound, resp., * are allowed. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nusefulconss : number of useful (non-obsolete) constraints to process * - nmarkedconss : number of constraints which are marked to be definitely propagated * - proptiming : current point in the node solving loop * - result : pointer to store the result of the propagation call * * possible return values for *result: * - SCIP_CUTOFF : the node is infeasible in the variable's bounds and can be cut off * - SCIP_REDUCEDDOM : at least one domain reduction was found * - SCIP_DIDNOTFIND : the propagator searched but did not find any domain reductions * - SCIP_DIDNOTRUN : the propagator was skipped * - SCIP_DELAYED : the propagator was skipped, but should be called again * - SCIP_DELAYNODE : the current node should be postponed (return value only valid for BEFORELP propagation) */ #define SCIP_DECL_CONSPROP(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, int nusefulconss, \ int nmarkedconss, SCIP_PROPTIMING proptiming, SCIP_RESULT* result) /** presolving method of constraint handler * * The presolver should go through the variables and constraints and tighten the domains or * constraints. Each tightening should increase the given total number of changes. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints to process * - nconss : number of constraints to process * - nrounds : number of presolving rounds already done * - presoltiming : current presolving timing * - nnewfixedvars : number of variables fixed since the last call to the presolving method * - nnewaggrvars : number of variables aggregated since the last call to the presolving method * - nnewchgvartypes : number of variable type changes since the last call to the presolving method * - nnewchgbds : number of variable bounds tightened since the last call to the presolving method * - nnewholes : number of domain holes added since the last call to the presolving method * - nnewdelconss : number of deleted constraints since the last call to the presolving method * - nnewaddconss : number of added constraints since the last call to the presolving method * - nnewupgdconss : number of upgraded constraints since the last call to the presolving method * - nnewchgcoefs : number of changed coefficients since the last call to the presolving method * - nnewchgsides : number of changed left or right hand sides since the last call to the presolving method * * @note the counters state the changes since the last call including the changes of this presolving method during its * call * * @note if the constraint handler performs dual presolving it is nesassary to check via calling SCIPallowWeakDualReds * and SCIPallowStrongDualReds if dual reductions are allowed. * * input/output: * - nfixedvars : pointer to count total number of variables fixed of all presolvers * - naggrvars : pointer to count total number of variables aggregated of all presolvers * - nchgvartypes : pointer to count total number of variable type changes of all presolvers * - nchgbds : pointer to count total number of variable bounds tightened of all presolvers * - naddholes : pointer to count total number of domain holes added of all presolvers * - ndelconss : pointer to count total number of deleted constraints of all presolvers * - naddconss : pointer to count total number of added constraints of all presolvers * - nupgdconss : pointer to count total number of upgraded constraints of all presolvers * - nchgcoefs : pointer to count total number of changed coefficients of all presolvers * - nchgsides : pointer to count total number of changed left/right hand sides of all presolvers * * output: * - result : pointer to store the result of the presolving call * * possible return values for *result: * - SCIP_UNBOUNDED : at least one variable is not bounded by any constraint in obj. direction -> problem is unbounded * - SCIP_CUTOFF : at least one constraint is infeasible in the variable's bounds -> problem is infeasible * - SCIP_SUCCESS : the presolving method found a reduction * - SCIP_DIDNOTFIND : the presolving method searched, but did not find a presolving change * - SCIP_DIDNOTRUN : the presolving method was skipped * - SCIP_DELAYED : the presolving method was skipped, but should be called again */ #define SCIP_DECL_CONSPRESOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss, int nrounds, \ SCIP_PRESOLTIMING presoltiming, int nnewfixedvars, int nnewaggrvars, int nnewchgvartypes, int nnewchgbds, int nnewholes, \ int nnewdelconss, int nnewaddconss, int nnewupgdconss, int nnewchgcoefs, int nnewchgsides, \ int* nfixedvars, int* naggrvars, int* nchgvartypes, int* nchgbds, int* naddholes, \ int* ndelconss, int* naddconss, int* nupgdconss, int* nchgcoefs, int* nchgsides, SCIP_RESULT* result) /** propagation conflict resolving method of constraint handler * * This method is called during conflict analysis. If the constraint handler wants to support conflict analysis, * it should call SCIPinferVarLbCons() or SCIPinferVarUbCons() in domain propagation instead of SCIPchgVarLb() or * SCIPchgVarUb() in order to deduce bound changes on variables. * In the SCIPinferVarLbCons() and SCIPinferVarUbCons() calls, the handler provides the constraint, that deduced the * variable's bound change, and an integer value "inferinfo" that can be arbitrarily chosen. * The propagation conflict resolving method can then be implemented, to provide a "reason" for the bound * changes, i.e., the bounds of variables at the time of the propagation, that forced the constraint to set the * conflict variable's bound to its current value. It can use the "inferinfo" tag to identify its own propagation * rule and thus identify the "reason" bounds. The bounds that form the reason of the assignment must then be provided * by calls to SCIPaddConflictLb(), SCIPaddConflictUb(), SCIPaddConflictBd(), SCIPaddConflictRelaxedLb(), * SCIPaddConflictRelaxedUb(), SCIPaddConflictRelaxedBd(), and/or SCIPaddConflictBinvar() in the propagation conflict * resolving method. * * For example, the logicor constraint c = "x or y or z" fixes variable z to TRUE (i.e. changes the lower bound of z * to 1.0), if both, x and y, are assigned to FALSE (i.e. if the upper bounds of these variables are 0.0). It uses * SCIPinferVarLbCons(scip, z, 1.0, c, 0) to apply this assignment (an inference information tag is not needed by the * constraint handler and is set to 0). * In the conflict analysis, the constraint handler may be asked to resolve the lower bound change on z with * constraint c, that was applied at a time given by a bound change index "bdchgidx". * With a call to SCIPgetVarLbAtIndex(scip, z, bdchgidx, TRUE), the handler can find out, that the lower bound of * variable z was set to 1.0 at the given point of time, and should call SCIPaddConflictUb(scip, x, bdchgidx) and * SCIPaddConflictUb(scip, y, bdchgidx) to tell SCIP, that the upper bounds of x and y at this point of time were * the reason for the deduction of the lower bound of z. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that deduced the bound change of the conflict variable * - infervar : the conflict variable whose bound change has to be resolved * - inferinfo : the user information passed to the corresponding SCIPinferVarLbCons() or SCIPinferVarUbCons() call * - boundtype : the type of the changed bound (lower or upper bound) * - bdchgidx : the index of the bound change, representing the point of time where the change took place * - relaxedbd : the relaxed bound which is sufficient to be explained * * output: * - result : pointer to store the result of the propagation conflict resolving call * * possible return values for *result: * - SCIP_SUCCESS : the conflicting bound change has been successfully resolved by adding all reason bounds * - SCIP_DIDNOTFIND : the conflicting bound change could not be resolved and has to be put into the conflict set * * @note it is sufficient to explain/resolve the relaxed bound */ #define SCIP_DECL_CONSRESPROP(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, \ SCIP_VAR* infervar, int inferinfo, SCIP_BOUNDTYPE boundtype, SCIP_BDCHGIDX* bdchgidx, SCIP_Real relaxedbd, \ SCIP_RESULT* result) /** variable rounding lock method of constraint handler * * This method is called, after a constraint is added or removed from the transformed problem. * It should update the rounding locks of the given type of all associated variables with calls to * SCIPaddVarLocksType(), depending on the way, the variable is involved in the constraint: * - If the constraint may get violated by decreasing the value of a variable, it should call * SCIPaddVarLocksType(scip, var, locktype, nlockspos, nlocksneg), saying that rounding down is * potentially rendering the (positive) constraint infeasible and rounding up is potentially rendering the * negation of the constraint infeasible. * - If the constraint may get violated by increasing the value of a variable, it should call * SCIPaddVarLocksType(scip, var, locktype, nlocksneg, nlockspos), saying that rounding up is * potentially rendering the constraint's negation infeasible and rounding up is potentially rendering the * constraint itself infeasible. * - If the constraint may get violated by changing the variable in any direction, it should call * SCIPaddVarLocksType(scip, var, locktype, nlockspos + nlocksneg, nlockspos + nlocksneg). * * Consider the linear constraint "3x -5y +2z <= 7" as an example. The variable rounding lock method of the * linear constraint handler should call SCIPaddVarLocksType(scip, x, locktype, nlocksneg, nlockspos), * SCIPaddVarLocksType(scip, y, locktype, nlockspos, nlocksneg) and * SCIPaddVarLocksType(scip, z, type, nlocksneg, nlockspos) to tell SCIP, that rounding up of x and z and rounding * down of y can destroy the feasibility of the constraint, while rounding down of x and z and rounding up of y can * destroy the feasibility of the constraint's negation "3x -5y +2z > 7". * A linear constraint "2 <= 3x -5y +2z <= 7" should call * SCIPaddVarLocksType(scip, ..., nlockspos + nlocksneg, nlockspos + nlocksneg) on all variables, since rounding in both * directions of each variable can destroy both the feasibility of the constraint and it's negation * "3x -5y +2z < 2 or 3x -5y +2z > 7". * * If the constraint itself contains other constraints as sub constraints (e.g. the "or" constraint concatenation * "c(x) or d(x)"), the rounding lock methods of these constraints should be called in a proper way. * - If the constraint may get violated by the violation of the sub constraint c, it should call * SCIPaddConsLocksType(scip, c, locktype, nlockspos, nlocksneg), saying that infeasibility of c may lead to * infeasibility of the (positive) constraint, and infeasibility of c's negation (i.e. feasibility of c) may lead * to infeasibility of the constraint's negation (i.e. feasibility of the constraint). * - If the constraint may get violated by the feasibility of the sub constraint c, it should call * SCIPaddConsLocksType(scip, c, locktype, nlocksneg, nlockspos), saying that infeasibility of c may lead to * infeasibility of the constraint's negation (i.e. feasibility of the constraint), and infeasibility of c's negation * (i.e. feasibility of c) may lead to infeasibility of the (positive) constraint. * - If the constraint may get violated by any change in the feasibility of the sub constraint c, it should call * SCIPaddConsLocksType(scip, c, locktype, nlockspos + nlocksneg, nlockspos + nlocksneg). * * Consider the or concatenation "c(x) or d(x)". The variable rounding lock method of the or constraint handler * should call SCIPaddConsLocksType(scip, c, locktype, nlockspos, nlocksneg) and * SCIPaddConsLocksType(scip, d, locktype, nlockspos, nlocksneg) to tell SCIP, that infeasibility of c and d can lead * to infeasibility of "c(x) or d(x)". * * As a second example, consider the equivalence constraint "y <-> c(x)" with variable y and constraint c. The * constraint demands, that y == 1 if and only if c(x) is satisfied. The variable lock method of the corresponding * constraint handler should call SCIPaddVarLocksType(scip, y, locktype, nlockspos + nlocksneg, nlockspos + nlocksneg) and * SCIPaddConsLocksType(scip, c, locktype, nlockspos + nlocksneg, nlockspos + nlocksneg), because any modification to the * value of y or to the feasibility of c can alter the feasibility of the equivalence constraint. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that should lock rounding of its variables, or NULL if the constraint handler * does not need constraints * - locktype : type of rounding locks, i.e., SCIP_LOCKTYPE_MODEL or SCIP_LOCKTYPE_CONFLICT * - nlockspos : number of times, the roundings should be locked for the constraint (may be negative) * - nlocksneg : number of times, the roundings should be locked for the constraint's negation (may be negative) */ #define SCIP_DECL_CONSLOCK(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, SCIP_LOCKTYPE locktype, int nlockspos, int nlocksneg) /** constraint activation notification method of constraint handler * * WARNING! There may exist unprocessed events. For example, a variable's bound may have been already changed, but * the corresponding bound change event was not yet processed. * * This method is always called after a constraint of the constraint handler was activated. The constraint * handler may use this call to update his own (statistical) data. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that has been activated */ #define SCIP_DECL_CONSACTIVE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons) /** constraint deactivation notification method of constraint handler * * WARNING! There may exist unprocessed events. For example, a variable's bound may have been already changed, but * the corresponding bound change event was not yet processed. * * This method is always called before a constraint of the constraint handler is deactivated. The constraint * handler may use this call to update his own (statistical) data. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that will be deactivated */ #define SCIP_DECL_CONSDEACTIVE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons) /** constraint enabling notification method of constraint handler * * WARNING! There may exist unprocessed events. For example, a variable's bound may have been already changed, but * the corresponding bound change event was not yet processed. * * This method is always called after a constraint of the constraint handler was enabled. The constraint * handler may use this call to update his own (statistical) data. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that has been enabled */ #define SCIP_DECL_CONSENABLE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons) /** constraint disabling notification method of constraint handler * * WARNING! There may exist unprocessed events. For example, a variable's bound may have been already changed, but * the corresponding bound change event was not yet processed. * * This method is always called before a constraint of the constraint handler is disabled. The constraint * handler may use this call to update his own (statistical) data. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that will be disabled */ #define SCIP_DECL_CONSDISABLE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons) /** variable deletion method of constraint handler * * This method is optinal and only of interest if you are using SCIP as a branch-and-price framework. That means, you * are generating new variables during the search. If you are not doing that just define the function pointer to be * NULL. * * If this method gets implemented you should iterate over all constraints of the constraint handler and delete all * variables that were marked for deletion by SCIPdelVar(). * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - conss : array of constraints in transformed problem * - nconss : number of constraints in transformed problem */ #define SCIP_DECL_CONSDELVARS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** conss, int nconss) /** constraint display method of constraint handler * * The constraint handler can store a representation of the constraint into the given text file. Use the method * SCIPinfoMessage() to push a string into the file stream. * * @note There are several methods which help to display variables. These are SCIPwriteVarName(), SCIPwriteVarsList(), * SCIPwriteVarsLinearsum(), and SCIPwriteVarsPolynomial(). * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that should be displayed * - file : the text file to store the information into */ #define SCIP_DECL_CONSPRINT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, FILE* file) /** constraint copying method of constraint handler * * The constraint handler can provide a copy method which copies a constraint from one SCIP data structure into an other * SCIP data structure. If a copy of a constraint is created, the constraint has to be captured. (The capture is usually * already done due to the creation of the constraint). * * If the copy process was one to one, the valid pointer can be set to TRUE. Otherwise, you have to set this pointer to * FALSE. In case all problem defining objects (constraint handlers and variable pricers) return a TRUE valid for all * their copying calls, SCIP assumes that it is a overall one to one copy of the original instance. In this case any * reductions made in the copied SCIP instance can be transfered to the original SCIP instance. If the valid pointer is * set to TRUE and it was not a one to one copy, it might happen that optimal solutions are cut off. * * To get a copy of a variable in the target SCIP you should use the function SCIPgetVarCopy(). * * input: * - scip : target SCIP data structure * - cons : pointer to store the created target constraint * - name : name of constraint, or NULL if the name of the source constraint should be used * - sourcescip : source SCIP data structure * - sourceconshdlr : source constraint handler of the source SCIP * - sourcecons : source constraint of the source SCIP * - varmap : a SCIP_HASHMAP mapping variables of the source SCIP to corresponding variables of the target SCIP * - consmap : a SCIP_HASHMAP mapping constraints of the source SCIP to corresponding constraints of the target SCIP * - initial : should the LP relaxation of constraint be in the initial LP? * - separate : should the constraint be separated during LP processing? * - enforce : should the constraint be enforced during node processing? * - check : should the constraint be checked for feasibility? * - propagate : should the constraint be propagated during node processing? * - local : is constraint only valid locally? * - modifiable : is constraint modifiable (subject to column generation)? * - dynamic : is constraint subject to aging? * - removable : should the relaxation be removed from the LP due to aging or cleanup? * - stickingatnode : should the constraint always be kept at the node where it was added, even * if it may be moved to a more global node? * - global : should a global or a local copy be created? * * output: * - valid : pointer to store whether the copying was valid or not */ #define SCIP_DECL_CONSCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONS** cons, const char* name, \ SCIP* sourcescip, SCIP_CONSHDLR* sourceconshdlr, SCIP_CONS* sourcecons, SCIP_HASHMAP* varmap, SCIP_HASHMAP* consmap, \ SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, \ SCIP_Bool local, SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode, \ SCIP_Bool global, SCIP_Bool* valid) /** constraint parsing method of constraint handler * * The constraint handler can provide a callback to parse the output created by the display method * (\ref SCIP_DECL_CONSPRINT) and to create a constraint out of it. * * @note For parsing there are several methods which are handy. Have a look at: SCIPparseVarName(), * SCIPparseVarsList(), SCIPparseVarsLinearsum(), SCIPparseVarsPolynomial(), SCIPstrToRealValue(), and * SCIPstrCopySection(). * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : pointer to store the created constraint * - name : name of the constraint * - str : string to parse * - initial : should the LP relaxation of constraint be in the initial LP? * - separate : should the constraint be separated during LP processing? * - enforce : should the constraint be enforced during node processing? * - check : should the constraint be checked for feasibility? * - propagate : should the constraint be propagated during node processing? * - local : is constraint only valid locally? * - modifiable : is constraint modifiable (subject to column generation)? * - dynamic : is constraint subject to aging? * - removable : should the relaxation be removed from the LP due to aging or cleanup? * - stickingatnode : should the constraint always be kept at the node where it was added, even * if it may be moved to a more global node? * output: * - success : pointer to store whether the parsing was successful or not */ #define SCIP_DECL_CONSPARSE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS** cons, \ const char* name, const char* str, \ SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, \ SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode, SCIP_Bool* success) /** constraint method of constraint handler which returns the variables (if possible) * * The constraint handler can (this callback is optional) provide this callback to return the variables which are * involved in that particular constraint. If this is possible, the variables should be copyied into the variables * array and the success pointers has to be set to TRUE. Otherwise the success has to be set FALSE or the callback * should not be implemented. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : the constraint that should return its variable data * - varssize : available slots in vars array which is needed to check if the array is large enough * * output: * - vars : array to store/copy the involved variables of the constraint * - success : pointer to store whether the variables are successfully copied */ #define SCIP_DECL_CONSGETVARS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, \ SCIP_VAR** vars, int varssize, SCIP_Bool* success) /** constraint method of constraint handler which returns the number of variables (if possible) * * The constraint handler can (this callback is optional) provide this callback to return the number variable which are * involved in that particular constraint. If this is not possible, the success pointers has to be set to FALSE or the * callback should not be implemented. * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - cons : constraint for which the number of variables is wanted * * output: * - nvars : pointer to store the number of variables * - success : pointer to store whether the constraint successfully returned the number of variables */ #define SCIP_DECL_CONSGETNVARS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_CONS* cons, \ int* nvars, SCIP_Bool* success) /** constraint handler method to suggest dive bound changes during the generic diving algorithm * * This callback is used inside the various diving heuristics of SCIP and does not affect the normal branching of the * actual search. The constraint handler can provide this callback to render the current solution (even more) * infeasible by suggesting one or several variable bound changes. In fact, since diving heuristics do not necessarily * solve LP relaxations at every probing depth, some of the variable local bounds might already be conflicting with the * solution values. The solution is rendered infeasible by determining bound changes that should be applied to the * next explored search node via SCIPaddDiveBoundChange(). An alternative in case that the preferred bound change(s) * were detected infeasible must be provided. * * The constraint handler must take care to only add bound changes that further shrink the variable domain. * * The success pointer must be used to indicate whether the constraint handler succeeded in selecting diving bound * changes. The infeasible pointer should be set to TRUE if the constraint handler found a local infeasibility. If the * constraint handler needs to select between several candidates, it may use the scoring mechanism of the diveset * argument to control its choice. * * This callback is optional. * * @note: @p sol is usually the LP relaxation solution unless the caller of the method, usually a diving heuristic, * does not solve LP relaxations at every depth * * input: * - scip : SCIP main data structure * - conshdlr : the constraint handler itself * - diveset : diving settings for scoring * - sol : current diving solution, usually the LP relaxation solution * * output: * - success : pointer to store whether the constraint handler succeeded to determine dive bound changes * - infeasible : pointer to store whether the constraint handler detected an infeasibility in the local node */ #define SCIP_DECL_CONSGETDIVEBDCHGS(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONSHDLR* conshdlr, SCIP_DIVESET* diveset, \ SCIP_SOL* sol, SCIP_Bool* success, SCIP_Bool* infeasible) #ifdef __cplusplus } #endif #endif