Scippy

SCIP

Solving Constraint Integer Programs

cons_lop.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 */
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17 /* See the License for the specific language governing permissions and */
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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 cons_lop.h
26  * @brief constraint handler for linear ordering constraints
27  * @author Marc Pfetsch
28  *
29  * This constraint ensures that a given square matrix of binary variables corresponds to a
30  * tournament, i.e., it is an acyclic orientation of the complete graph. This encodes a linear order
31  * as follows. The rows and columns correspond to the elements of the set to be ordered. A variable
32  * x[i][j] is 1 if and only if element i appears before j in the order.
33  *
34  * In this constraint handler we only add the symmetry equations and separate the triangle
35  * inequalities yielding a correct IP model.
36  *
37  * The variables on the diagonal are ignored.
38  */
39 
40 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
41 
42 #ifndef __LOP_CONS_LOP_H__
43 #define __LOP_CONS_LOP_H__
44 
45 
46 #include <scip/scip.h>
47 
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51 
52 /** creates the handler for linear ordering constraints and includes it in SCIP */
54  SCIP* scip /**< SCIP data structure */
55  );
56 
57 /** creates and captures a linear ordering constraint */
59  SCIP* scip, /**< SCIP data structure */
60  SCIP_CONS** cons, /**< pointer to hold the created constraint */
61  const char* name, /**< name of constraint */
62  int n, /**< number of elements */
63  SCIP_VAR*** vars, /**< n x n matrix of binary variables */
64  SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP? */
65  SCIP_Bool separate, /**< should the constraint be separated during LP processing? */
66  SCIP_Bool enforce, /**< should the constraint be enforced during node processing? */
67  SCIP_Bool check, /**< should the constraint be checked for feasibility? */
68  SCIP_Bool propagate, /**< should the constraint be propagated during node processing? */
69  SCIP_Bool local, /**< is constraint only valid locally? */
70  SCIP_Bool modifiable, /**< is constraint modifiable (subject to column generation)? */
71  SCIP_Bool dynamic, /**< is constraint subject to aging? */
72  SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup? */
73  SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
74  * if it may be moved to a more global node? */
75  );
76 
77 #ifdef __cplusplus
78 }
79 #endif
80 
81 #endif
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
#define SCIP_Bool
Definition: def.h:93
SCIP_RETCODE SCIPincludeConshdlrLOP(SCIP *scip)
Definition: cons_lop.c:1177
SCIP callable library.
SCIP_RETCODE SCIPcreateConsLOP(SCIP *scip, SCIP_CONS **cons, const char *name, int n, 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)
Definition: cons_lop.c:1205