Scippy

SCIP

Solving Constraint Integer Programs

sepa_mcf.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. */
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21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22 /* */
23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24 
25 /**@file sepa_mcf.h
26  * @ingroup SEPARATORS
27  * @brief multi-commodity-flow network cut separator
28  * @author Tobias Achterberg
29  * @author Christian Raack
30  *
31  * We try to identify a multi-commodity flow structure in the LP relaxation of the
32  * following type:
33  *
34  * (1) sum_{a in delta^+(v)} f_a^k - sum_{a in delta^-(v)} f_a^k <= -d_v^k for all v in V and k in K
35  * (2) sum_{k in K} f_a^k - c_a x_a <= 0 for all a in A
36  *
37  * Constraints (1) are flow conservation constraints, which say that for each commodity k and node v the
38  * outflow (delta^+(v)) minus the inflow (delta^-(v)) of a node v must not exceed the negative of the demand of
39  * node v in commodity k. To say it the other way around, inflow minus outflow must be at least equal to the demand.
40  * Constraints (2) are the arc capacity constraints, which say that the sum of all flow over an arc a must not
41  * exceed its capacity c_a x_a, with x being a binary or integer variable.
42  * c_a x_a does not need to be a single product of a capacity and an integer variable; we also accept general scalar
43  * products.
44  */
45 
46 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
47 
48 #ifndef __SCIP_SEPA_MCF_H__
49 #define __SCIP_SEPA_MCF_H__
50 
51 #include "scip/def.h"
52 #include "scip/type_retcode.h"
53 #include "scip/type_scip.h"
54 #ifdef __cplusplus
55 extern "C" {
56 #endif
57 
58 /** creates the mcf separator and includes it in SCIP
59  *
60  * @ingroup SeparatorIncludes
61  */
62 SCIP_EXPORT
64  SCIP* scip /**< SCIP data structure */
65  );
66 
67 #ifdef __cplusplus
68 }
69 #endif
70 
71 #endif
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
type definitions for return codes for SCIP methods
type definitions for SCIP&#39;s main datastructure
SCIP_RETCODE SCIPincludeSepaMcf(SCIP *scip)
Definition: sepa_mcf.c:6917
common defines and data types used in all packages of SCIP