Scippy

SCIP

Solving Constraint Integer Programs

cons_logicor.h
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
6 /* Copyright (C) 2002-2021 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SCIP is distributed under the terms of the ZIB Academic License. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file cons_logicor.h
17  * @ingroup CONSHDLRS
18  * @brief Constraint handler for logicor constraints \f$1^T x \ge 1\f$ (equivalent to set covering, but algorithms are suited for depth first search).
19  * @author Tobias Achterberg
20  * @author Michael Winkler
21  *
22  */
23 
24 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
25 
26 #ifndef __SCIP_CONS_LOGICOR_H__
27 #define __SCIP_CONS_LOGICOR_H__
28 
29 
30 #include "scip/def.h"
31 #include "scip/type_cons.h"
32 #include "scip/type_lp.h"
33 #include "scip/type_retcode.h"
34 #include "scip/type_scip.h"
35 #include "scip/type_var.h"
36 
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40 
41 /** creates the handler for logic or constraints and includes it in SCIP
42  *
43  * @ingroup ConshdlrIncludes
44  * */
47  SCIP* scip /**< SCIP data structure */
48  );
49 
50 /**@addtogroup CONSHDLRS
51  *
52  * @{
53  *
54  * @name Logicor Constraints
55  *
56  * @{
57  *
58  * This constraint handler handles a special type of linear constraints, namely
59  * logic or constraints. These are equivalent to set covering constraints, but
60  * are handled by special algorithms which are better suited for depth first search.
61  * For a set of binary variables \f$x_i, i=1,\dots,n\f$, a logic or constraint has the form
62  * \f[
63  * \sum_{i=1}^n x_i \ge 1.
64  * \f]
65  */
66 
67 /** creates and captures a logic or constraint
68  *
69  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
70  */
73  SCIP* scip, /**< SCIP data structure */
74  SCIP_CONS** cons, /**< pointer to hold the created constraint */
75  const char* name, /**< name of constraint */
76  int nvars, /**< number of variables in the constraint */
77  SCIP_VAR** vars, /**< array with variables of constraint entries */
78  SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP?
79  * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
80  SCIP_Bool separate, /**< should the constraint be separated during LP processing?
81  * Usually set to TRUE. */
82  SCIP_Bool enforce, /**< should the constraint be enforced during node processing?
83  * TRUE for model constraints, FALSE for additional, redundant constraints. */
84  SCIP_Bool check, /**< should the constraint be checked for feasibility?
85  * TRUE for model constraints, FALSE for additional, redundant constraints. */
86  SCIP_Bool propagate, /**< should the constraint be propagated during node processing?
87  * Usually set to TRUE. */
88  SCIP_Bool local, /**< is constraint only valid locally?
89  * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
90  SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)?
91  * Usually set to FALSE. In column generation applications, set to TRUE if pricing
92  * adds coefficients to this constraint. */
93  SCIP_Bool dynamic, /**< is constraint subject to aging?
94  * Usually set to FALSE. Set to TRUE for own cuts which
95  * are separated as constraints. */
96  SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup?
97  * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
98  SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
99  * if it may be moved to a more global node?
100  * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
101  );
102 
103 /** creates and captures a logicor constraint
104  * in its most basic version, i. e., all constraint flags are set to their basic value as explained for the
105  * method SCIPcreateConsLogicor(); all flags can be set via SCIPsetConsFLAGNAME-methods in scip.h
106  *
107  * @see SCIPcreateConsLogicor() for information about the basic constraint flag configuration
108  *
109  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
110  */
113  SCIP* scip, /**< SCIP data structure */
114  SCIP_CONS** cons, /**< pointer to hold the created constraint */
115  const char* name, /**< name of constraint */
116  int nvars, /**< number of variables in the constraint */
117  SCIP_VAR** vars /**< array with variables of constraint entries */
118  );
119 
120 /** adds coefficient in logic or constraint */
123  SCIP* scip, /**< SCIP data structure */
124  SCIP_CONS* cons, /**< logicor constraint */
125  SCIP_VAR* var /**< variable to add to the constraint */
126  );
127 
128 /** gets number of variables in logic or constraint */
131  SCIP* scip, /**< SCIP data structure */
132  SCIP_CONS* cons /**< constraint data */
133  );
134 
135 /** gets array of variables in logic or constraint */
138  SCIP* scip, /**< SCIP data structure */
139  SCIP_CONS* cons /**< constraint data */
140  );
141 
142 /** gets the dual solution of the logic or constraint in the current LP */
145  SCIP* scip, /**< SCIP data structure */
146  SCIP_CONS* cons /**< constraint data */
147  );
148 
149 /** gets the dual Farkas value of the logic or constraint in the current infeasible LP */
152  SCIP* scip, /**< SCIP data structure */
153  SCIP_CONS* cons /**< constraint data */
154  );
155 
156 /** returns the linear relaxation of the given logic or constraint; may return NULL if no LP row was yet created;
157  * the user must not modify the row!
158  */
161  SCIP* scip, /**< SCIP data structure */
162  SCIP_CONS* cons /**< constraint data */
163  );
164 
165 /** cleans up (multi-)aggregations and fixings from logicor constraints */
168  SCIP* scip, /**< SCIP data structure */
169  SCIP_Bool onlychecked, /**< should only checked constraints be cleaned up? */
170  int* naddconss, /**< pointer to count number of added (linear) constraints */
171  int* ndelconss, /**< pointer to count number of deleted (logicor) constraints */
172  int* nchgcoefs /**< pointer to count number of changed coefficients */
173  );
174 
175 /** @} */
176 
177 /** @} */
178 
179 #ifdef __cplusplus
180 }
181 #endif
182 
183 #endif
SCIP_EXPORT SCIP_RETCODE SCIPcreateConsLogicor(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, 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)
#define SCIP_EXPORT
Definition: def.h:100
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:54
type definitions for return codes for SCIP methods
SCIP_EXPORT SCIP_Real SCIPgetDualsolLogicor(SCIP *scip, SCIP_CONS *cons)
type definitions for LP management
SCIP_EXPORT SCIP_RETCODE SCIPaddCoefLogicor(SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var)
type definitions for SCIP&#39;s main datastructure
type definitions for problem variables
SCIP_EXPORT SCIP_VAR ** SCIPgetVarsLogicor(SCIP *scip, SCIP_CONS *cons)
#define SCIP_Bool
Definition: def.h:70
SCIP_EXPORT SCIP_Real SCIPgetDualfarkasLogicor(SCIP *scip, SCIP_CONS *cons)
SCIP_EXPORT SCIP_RETCODE SCIPcleanupConssLogicor(SCIP *scip, SCIP_Bool onlychecked, int *naddconss, int *ndelconss, int *nchgcoefs)
SCIP_EXPORT SCIP_RETCODE SCIPincludeConshdlrLogicor(SCIP *scip)
SCIP_EXPORT int SCIPgetNVarsLogicor(SCIP *scip, SCIP_CONS *cons)
#define SCIP_Real
Definition: def.h:163
SCIP_EXPORT SCIP_RETCODE SCIPcreateConsBasicLogicor(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars)
SCIP_EXPORT SCIP_ROW * SCIPgetRowLogicor(SCIP *scip, SCIP_CONS *cons)
common defines and data types used in all packages of SCIP
type definitions for constraints and constraint handlers