text: /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
  /*                                                                           */
  /*                  This file is part of the program and library             */
  /*         SCIP --- Solving Constraint Integer Programs                      */
  /*                                                                           */
  /*    Copyright (C) 2002-2018 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 email to scip@zib.de.      */
  /*                                                                           */
  /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
  
  /**@file   cons_sos1.h
   * @ingroup CONSHDLRS
   * @brief  constraint handler for SOS type 1 constraints
   * @author Tobias Fischer
   * @author Marc Pfetsch
   *
   */
  
  /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
  
  #ifndef __SCIP_CONS_SOS1_H__
  #define __SCIP_CONS_SOS1_H__
  
  
  #include "scip/scip.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /** creates the handler for SOS1 constraints and includes it in SCIP
   *
   * @ingroup ConshdlrIncludes
   * */
  EXTERN
  SCIP_RETCODE SCIPincludeConshdlrSOS1(
     SCIP*                 scip                /**< SCIP data structure */
     );
  
  /**@addtogroup CONSHDLRS
   *
   * @{
   *
   * @name Specially Ordered Set (SOS) Type 1 Constraints
   *
   * @{
   *
   * A specially ordered set of type 1 (SOS1) is a sequence of variables such that at most one
   * variable is nonzero. The special case of two variables arises, for instance, from equilibrium or
   * complementary conditions like \f$x \cdot y = 0\f$. Note that it is in principle allowed that a
   * variable appears twice, but it then can be fixed to 0.
   */
  
  /** creates and captures an SOS1 constraint
   *
   *  We set the constraint to not be modifable. If the weights are non
   *  NULL, the variables are ordered according to these weights (in
   *  ascending order).
   *
   *  @note The constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons().
   */
  EXTERN
  SCIP_RETCODE SCIPcreateConsSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
     const char*           name,               /**< name of constraint */
     int                   nvars,              /**< number of variables in the constraint */
     SCIP_VAR**            vars,               /**< array with variables of constraint entries */
     SCIP_Real*            weights,            /**< weights determining the variable order, or NULL if natural order should be used */
     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             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 SOS1 constraint
   *  in its most basic variant, i. e., with all constraint flags set to their default values, which can be set
   *  afterwards using SCIPsetConsFLAGNAME() in scip.h
   *
   *  @see SCIPcreateConsSOS1() for the default constraint flag configuration
   *
   *  @warning Do NOT set the constraint to be modifiable manually, because this might lead
   *  to wrong results as the variable array will not be resorted
   *
   *  @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
   */
  EXTERN
  SCIP_RETCODE SCIPcreateConsBasicSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS**           cons,               /**< pointer to hold the created constraint */
     const char*           name,               /**< name of constraint */
     int                   nvars,              /**< number of variables in the constraint */
     SCIP_VAR**            vars,               /**< array with variables of constraint entries */
     SCIP_Real*            weights             /**< weights determining the variable order, or NULL if natural order should be used */
     );
  
  /** adds variable to SOS1 constraint, the position is determined by the given weight */
  EXTERN
  SCIP_RETCODE SCIPaddVarSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS*            cons,               /**< constraint */
     SCIP_VAR*             var,                /**< variable to add to the constraint */
     SCIP_Real             weight              /**< weight determining position of variable */
     );
  
  /** appends variable to SOS1 constraint */
  EXTERN
  SCIP_RETCODE SCIPappendVarSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS*            cons,               /**< constraint */
     SCIP_VAR*             var                 /**< variable to add to the constraint */
     );
  
  /** gets number of variables in SOS1 constraint */
  EXTERN
  int SCIPgetNVarsSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS*            cons                /**< constraint */
     );
  
  /** gets array of variables in SOS1 constraint */
  EXTERN
  SCIP_VAR** SCIPgetVarsSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS*            cons                /**< constraint data */
     );
  
  /** gets array of weights in SOS1 constraint (or NULL if not existent) */
  EXTERN
  SCIP_Real* SCIPgetWeightsSOS1(
     SCIP*                 scip,               /**< SCIP data structure */
     SCIP_CONS*            cons                /**< constraint data */
     );
  
  /** gets conflict graph of SOS1 constraints (or NULL if not existent)
   *
   *  @note The conflict graph is globally valid; local changes are not taken into account.
   */
  EXTERN
  SCIP_DIGRAPH* SCIPgetConflictgraphSOS1(
     SCIP_CONSHDLR*        conshdlr            /**< SOS1 constraint handler */
     );
  
  /** gets number of problem variables that are part of the SOS1 conflict graph */
  EXTERN
  int SCIPgetNSOS1Vars(
     SCIP_CONSHDLR*        conshdlr            /**< SOS1 constraint handler */
     );
  
  /** returns whether variable is part of the SOS1 conflict graph */
  EXTERN
  SCIP_Bool SCIPvarIsSOS1(
     SCIP_CONSHDLR*        conshdlr,           /**< SOS1 constraint handler */
     SCIP_VAR*             var                 /**< variable */
     );
  
  /** returns node of variable in the conflict graph or -1 if variable is not part of the SOS1 conflict graph */
  EXTERN
  int SCIPvarGetNodeSOS1(
     SCIP_CONSHDLR*        conshdlr,           /**< SOS1 constraint handler */
     SCIP_VAR*             var                 /**< variable */
     );
  
  /** returns variable that belongs to a given node from the conflict graph */
  EXTERN
  SCIP_VAR* SCIPnodeGetVarSOS1(
     SCIP_DIGRAPH*         conflictgraph,      /**< conflict graph */
     int                   node                /**< node from the conflict graph */
     );
  
  /** based on solution values of the variables, fixes variables to zero to turn all SOS1 constraints feasible  */
  EXTERN
  SCIP_RETCODE SCIPmakeSOS1sFeasible(
     SCIP*                 scip,               /**< SCIP pointer */
     SCIP_CONSHDLR*        conshdlr,           /**< SOS1 constraint handler */
     SCIP_SOL*             sol,                /**< solution */
     SCIP_Bool*            changed,            /**< pointer to store whether the solution has been changed */
     SCIP_Bool*            success             /**< pointer to store whether SOS1 constraints have been turned feasible and
                                                *   solution was good enough */
     );
  
  /* @} */
  
  /* @} */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  