Scippy

SCIP

Solving Constraint Integer Programs

type_conflict.h
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4 /* SCIP --- Solving Constraint Integer Programs */
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24 
25 /**@file type_conflict.h
26  * @ingroup TYPEDEFINITIONS
27  * @brief type definitions for conflict analysis
28  * @author Tobias Achterberg
29  *
30  * This file defines the interface for conflict handler implemented in C.
31  *
32  */
33 
34 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
35 
36 #ifndef __SCIP_TYPE_CONFLICT_H__
37 #define __SCIP_TYPE_CONFLICT_H__
38 
39 #include "scip/def.h"
40 #include "scip/type_retcode.h"
41 #include "scip/type_result.h"
42 #include "scip/type_var.h"
43 
44 #ifdef __cplusplus
45 extern "C" {
46 #endif
47 
48 typedef struct SCIP_Conflicthdlr SCIP_CONFLICTHDLR; /**< conflict handler to process conflict sets */
49 typedef struct SCIP_ConflicthdlrData SCIP_CONFLICTHDLRDATA; /**< conflict handler data */
50 typedef struct SCIP_ConflictSet SCIP_CONFLICTSET; /**< set of conflicting bound changes */
51 typedef struct SCIP_ProofSet SCIP_PROOFSET; /**< set of variables and coefficients describing a proof-constraint of type a^Tx <= rhs */
52 typedef struct SCIP_LPBdChgs SCIP_LPBDCHGS; /**< set of LP bound changes */
53 typedef struct SCIP_Conflict SCIP_CONFLICT; /**< conflict analysis data structure */
54 
55 /** types of conflicts */
57 {
58  SCIP_CONFTYPE_UNKNOWN = 0, /**< unknown type */
59  SCIP_CONFTYPE_PROPAGATION = 1, /**< conflict results from propagation */
60  SCIP_CONFTYPE_INFEASLP = 2, /**< conflict results from an infeasible LP relaxation */
61  SCIP_CONFTYPE_BNDEXCEEDING = 3, /**< conflict results from a boundexceeding LP relaxation */
62  SCIP_CONFTYPE_ALTINFPROOF = 4, /**< alternative proof of an infeasible LP relaxation */
63  SCIP_CONFTYPE_ALTBNDPROOF = 5 /**< alternative proof of a boundexceeding LP relaxation */
64 };
66 
67 /** dualray presolving strategy */
69 {
70  SCIP_CONFPRES_DISABLED = 0, /**< no presolving */
71  SCIP_CONFPRES_ONLYLOCAL = 1, /**< keep variables contributing with its local bound */
72  SCIP_CONFPRES_ONLYGLOBAL = 2, /**< keep variables contributing with its global bound */
73  SCIP_CONFPRES_BOTH = 3 /**< keep variables contributing with its global bound and add a few
74  * variables contributing with its local bound such that the
75  * constraint is not globally redundant
76  */
77 };
79 
80 /** copy method for conflict handler plugins (called when SCIP copies plugins)
81  *
82  * input:
83  * - scip : SCIP main data structure
84  * - conflicthdlr : the conflict handler itself
85  */
86 #define SCIP_DECL_CONFLICTCOPY(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
87 
88 /** destructor of conflict handler to free conflict handler data (called when SCIP is exiting)
89  *
90  * input:
91  * - scip : SCIP main data structure
92  * - conflicthdlr : the conflict handler itself
93  */
94 #define SCIP_DECL_CONFLICTFREE(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
95 
96 /** initialization method of conflict handler (called after problem was transformed)
97  *
98  * input:
99  * - scip : SCIP main data structure
100  * - conflicthdlr : the conflict handler itself
101  */
102 #define SCIP_DECL_CONFLICTINIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
103 
104 /** deinitialization method of conflict handler (called before transformed problem is freed)
105  *
106  * input:
107  * - scip : SCIP main data structure
108  * - conflicthdlr : the conflict handler itself
109  */
110 #define SCIP_DECL_CONFLICTEXIT(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
111 
112 /** solving process initialization method of conflict handler (called when branch and bound process is about to begin)
113  *
114  * This method is called when the presolving was finished and the branch and bound process is about to begin.
115  * The conflict handler may use this call to initialize its branch and bound specific data.
116  *
117  * input:
118  * - scip : SCIP main data structure
119  * - conflicthdlr : the conflict handler itself
120  */
121 #define SCIP_DECL_CONFLICTINITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
122 
123 /** solving process deinitialization method of conflict handler (called before branch and bound process data is freed)
124  *
125  * This method is called before the branch and bound process is freed.
126  * The conflict handler should use this call to clean up its branch and bound data.
127  *
128  * input:
129  * - scip : SCIP main data structure
130  * - conflicthdlr : the conflict handler itself
131  */
132 #define SCIP_DECL_CONFLICTEXITSOL(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr)
133 
134 /** conflict processing method of conflict handler (called when conflict was found)
135  *
136  * This method is called, when the conflict analysis found a conflict on variable bounds.
137  * The conflict handler may update its data accordingly and create a constraint out of the conflict set.
138  * If the parameter "resolved" is set, the conflict handler should not create a constraint, because
139  * a different conflict handler with higher priority already created a constraint.
140  * The bounds in the conflict set lead to a conflict (i.e. an infeasibility) when all enforced at the same time.
141  * Thus, a feasible conflict constraint must demand that at least one of the variables in the conflict
142  * set violates its corresponding bound, i.e., fulfills the negation of the bound change in the conflict set.
143  * For continuous variables, the negation has to be defined in a relaxed way: if, e.g., the bound in the conflict
144  * set is "x <= u", the negation to be used has to be "x >= u", and not "x > u".
145  * The given "bdchginfos" array representing the conflict set is only a reference to an internal
146  * buffer, that may be modified at any time by SCIP. The user must copy the needed information from the
147  * "bdchginfos" array to own data structures, if (s)he wants to use the information later.
148  * (S)he should not keep a pointer to the array or pointers to the single bdchginfos in the array, because these
149  * may get invalid afterwards.
150  *
151  * input:
152  * - scip : SCIP main data structure
153  * - conflicthdlr : the conflict handler itself
154  * - node : node to add resulting conflict constraint to (with SCIPaddConsNode())
155  * - validnode : node at which the conflict constraint is valid (should be passed to SCIPaddConsNode())
156  * - bdchginfos : array with bound changes that lead to a conflict
157  * - relaxedbds : array with relaxed bounds which are efficient to create a valid conflict
158  * - nbdchginfos : number of bound changes in the conflict set
159  * -.primalbound : the current primal bound, or -infininity if the conflict arises from an infeasible LP
160  * - separate : should the conflict constraint be separated?
161  * - local : is the conflict set only valid locally, i.e., should the constraint be created as local constraint?
162  * - dynamic : should the conflict constraint be made subject to aging?
163  * - removable : should the conflict's relaxation be made subject to LP aging and cleanup?
164  * - resolved : is the conflict set already used to create a constraint?
165  * - result : pointer to store the result of the conflict processing call
166  *
167  * possible return values for *result:
168  * - SCIP_CONSADDED : the conflict handler created a constraint out of the conflict set
169  * - SCIP_DIDNOTFIND : the conflict handler could not create a constraint out of the conflict set
170  * - SCIP_DIDNOTRUN : the conflict handler was skipped
171  */
172 #define SCIP_DECL_CONFLICTEXEC(x) SCIP_RETCODE x (SCIP* scip, SCIP_CONFLICTHDLR* conflicthdlr, SCIP_NODE* node, \
173  SCIP_NODE* validnode, SCIP_BDCHGINFO** bdchginfos, SCIP_Real* relaxedbds, int nbdchginfos, SCIP_CONFTYPE conftype, \
174  SCIP_Bool cutoffinvolved, SCIP_Bool separate, SCIP_Bool local, SCIP_Bool dynamic, SCIP_Bool removable, \
175  SCIP_Bool resolved, SCIP_RESULT* result)
176 
177 #ifdef __cplusplus
178 }
179 #endif
180 
181 #endif
type definitions for return codes for SCIP methods
SCIP_ConflictPresolStrat
Definition: type_conflict.h:68
SCIP_ConflictType
Definition: type_conflict.h:56
struct SCIP_ConflicthdlrData SCIP_CONFLICTHDLRDATA
Definition: type_conflict.h:49
type definitions for problem variables
enum SCIP_ConflictPresolStrat SCIP_CONFPRES
Definition: type_conflict.h:78
result codes for SCIP callback methods
enum SCIP_ConflictType SCIP_CONFTYPE
Definition: type_conflict.h:65
common defines and data types used in all packages of SCIP