cons_and.h

Go to the documentation of this file.

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
/*                                                                           */
/*    Copyright (C) 2002-2019 Konrad-Zuse-Zentrum                            */
/*                            fuer Informationstechnik Berlin                */
/*                                                                           */
/*  SCIP is distributed under the terms of the ZIB Academic License.         */
/*                                                                           */
/*  You should have received a copy of the ZIB Academic License              */
/*  along with SCIP; see the file COPYING. If not visit scip.zib.de.         */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file   cons_and.h
 * @ingroup CONSHDLRS
 * @brief  Constraint handler for AND constraints,  \f$r = x_1 \wedge x_2 \wedge \dots  \wedge x_n\f$
 * @author Tobias Achterberg
 * @author Stefan Heinz
 * @author Michael Winkler
 *
 */

/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/

#ifndef __SCIP_CONS_AND_H__
#define __SCIP_CONS_AND_H__


#include "scip/def.h"
#include "scip/type_cons.h"
#include "scip/type_retcode.h"
#include "scip/type_scip.h"
#include "scip/type_var.h"

#ifdef __cplusplus
extern "C" {
#endif

/** creates the handler for and constraints and includes it in SCIP
 *
 * @ingroup ConshdlrIncludes
 * */
extern
SCIP_RETCODE SCIPincludeConshdlrAnd(
   SCIP*                 scip                /**< SCIP data structure */
   );

/**@addtogroup CONSHDLRS
 *
 * @{
 *
 * @name AND Constraints
 *
 * @{
 *
 * This constraint handler deals with AND-constraints. These are constraint of the form:
 *
 * \f[
 *    r = x_1 \wedge x_2 \wedge \dots  \wedge x_n
 * \f]
 *
 * where \f$x_i\f$ is a binary variable for all \f$i\f$. Hence, \f$r\f$ is also of binary type. The variable \f$r\f$ is
 * called resultant and the \f$x\f$'s operators.
 */

/** creates and captures an and constraint
 *
 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
 */
extern
SCIP_RETCODE SCIPcreateConsAnd(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
   const char*           name,               /**< name of constraint */
   SCIP_VAR*             resvar,             /**< resultant variable of the operation */
   int                   nvars,              /**< number of operator variables in the constraint */
   SCIP_VAR**            vars,               /**< array with operator variables of constraint */
   SCIP_Bool             initial,            /**< should the LP relaxation of constraint be in the initial LP?
                                              *   Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
   SCIP_Bool             separate,           /**< should the constraint be separated during LP processing?
                                              *   Usually set to TRUE. */
   SCIP_Bool             enforce,            /**< should the constraint be enforced during node processing?
                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
   SCIP_Bool             check,              /**< should the constraint be checked for feasibility?
                                              *   TRUE for model constraints, FALSE for additional, redundant constraints. */
   SCIP_Bool             propagate,          /**< should the constraint be propagated during node processing?
                                              *   Usually set to TRUE. */
   SCIP_Bool             local,              /**< is constraint only valid locally?
                                              *   Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
   SCIP_Bool             modifiable,         /**< is constraint modifiable (subject to column generation)?
                                              *   Usually set to FALSE. In column generation applications, set to TRUE if pricing
                                              *   adds coefficients to this constraint. */
   SCIP_Bool             dynamic,            /**< is constraint subject to aging?
                                              *   Usually set to FALSE. Set to TRUE for own cuts which
                                              *   are separated as constraints. */
   SCIP_Bool             removable,          /**< should the relaxation be removed from the LP due to aging or cleanup?
                                              *   Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
   SCIP_Bool             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?
                                              *   Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
   );

/** creates and captures an and constraint
 *  in its most basic version, i. e., all constraint flags are set to their basic value as explained for the
 *  method SCIPcreateConsAnd(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h
 *
 *  @see SCIPcreateConsAnd() for information about the basic constraint flag configuration
 *
 *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
 */
extern
SCIP_RETCODE SCIPcreateConsBasicAnd(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
   const char*           name,               /**< name of constraint */
   SCIP_VAR*             resvar,             /**< resultant variable of the operation */
   int                   nvars,              /**< number of operator variables in the constraint */
   SCIP_VAR**            vars                /**< array with operator variables of constraint */
   );

/** gets number of variables in and constraint */
extern
int SCIPgetNVarsAnd(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons                /**< constraint data */
   );

/** gets array of variables in and constraint */
extern
SCIP_VAR** SCIPgetVarsAnd(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons                /**< constraint data */
   );

/** gets the resultant variable in and constraint */
extern
SCIP_VAR* SCIPgetResultantAnd(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons                /**< constraint data */
   );

/** return if the variables of the AND-constraint are sorted with respect to their indices */
extern
SCIP_Bool SCIPisAndConsSorted(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons                /**< constraint data */
   );

/** sort the variables of the AND-constraint with respect to their indices */
extern
SCIP_RETCODE SCIPsortAndCons(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons                /**< constraint data */
   );

/** when 'upgrading' the given AND-constraint, should the check flag for the upgraded constraint be set to TRUE, even if
 *  the check flag of this AND-constraint is set to FALSE?
 */
extern
SCIP_RETCODE SCIPchgAndConsCheckFlagWhenUpgr(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons,               /**< constraint data */
   SCIP_Bool             flag                /**< should an arising constraint from the given AND-constraint be checked,
                                              *   even if the check flag of the AND-constraint is set to FALSE
                                              */
   );

/** when 'upgrading' the given AND-constraint, should the removable flag for the upgraded constraint be set to FALSE,
 *  even if the removable flag of this AND-constraint is set to TRUE?
 */
extern
SCIP_RETCODE SCIPchgAndConsRemovableFlagWhenUpgr(
   SCIP*                 scip,               /**< SCIP data structure */
   SCIP_CONS*            cons,               /**< constraint data */
   SCIP_Bool             flag                /**< should an arising constraint from the given AND-constraint be not
                                              *   removable, even if the removable flag of the AND-constraint is set to
                                              *   TRUE
                                              */
   );

/* @} */

/* @} */

#ifdef __cplusplus
}
#endif

#endif