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