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type_conflict.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) 2002-2023 Zuse Institute Berlin (ZIB) */
7/* */
8/* Licensed under the Apache License, Version 2.0 (the "License"); */
9/* you may not use this file except in compliance with the License. */
10/* You may obtain a copy of the License at */
11/* */
12/* http://www.apache.org/licenses/LICENSE-2.0 */
13/* */
14/* Unless required by applicable law or agreed to in writing, software */
15/* distributed under the License is distributed on an "AS IS" BASIS, */
16/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17/* See the License for the specific language governing permissions and */
18/* limitations under the License. */
19/* */
20/* You should have received a copy of the Apache-2.0 license */
21/* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22/* */
23/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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
45extern "C" {
46#endif
47
48typedef struct SCIP_Conflicthdlr SCIP_CONFLICTHDLR; /**< conflict handler to process conflict sets */
49typedef struct SCIP_ConflicthdlrData SCIP_CONFLICTHDLRDATA; /**< conflict handler data */
50typedef struct SCIP_ConflictSet SCIP_CONFLICTSET; /**< set of conflicting bound changes */
51typedef struct SCIP_ProofSet SCIP_PROOFSET; /**< set of variables and coefficients describing a proof-constraint of type a^Tx <= rhs */
52typedef struct SCIP_LPBdChgs SCIP_LPBDCHGS; /**< set of LP bound changes */
53typedef 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
common defines and data types used in all packages of SCIP
enum SCIP_ConflictPresolStrat SCIP_CONFPRES
SCIP_ConflictType
@ SCIP_CONFTYPE_ALTINFPROOF
@ SCIP_CONFTYPE_BNDEXCEEDING
@ SCIP_CONFTYPE_PROPAGATION
@ SCIP_CONFTYPE_ALTBNDPROOF
@ SCIP_CONFTYPE_INFEASLP
@ SCIP_CONFTYPE_UNKNOWN
enum SCIP_ConflictType SCIP_CONFTYPE
SCIP_ConflictPresolStrat
@ SCIP_CONFPRES_ONLYLOCAL
@ SCIP_CONFPRES_ONLYGLOBAL
@ SCIP_CONFPRES_DISABLED
@ SCIP_CONFPRES_BOTH
struct SCIP_ConflicthdlrData SCIP_CONFLICTHDLRDATA
result codes for SCIP callback methods
type definitions for return codes for SCIP methods
type definitions for problem variables