Scippy

SCIP

Solving Constraint Integer Programs

heur_twoopt.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) 2002-2016 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SCIP is distributed under the terms of the ZIB Academic License. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SCIP; see the file COPYING. If not email to scip@zib.de. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file heur_twoopt.h
17  * @ingroup PRIMALHEURISTICS
18  * @brief Primal heuristic to improve incumbent solution by flipping pairs of variables
19  * @author Timo Berthold
20  * @author Gregor Hendel
21  *
22  * The Twoopt heuristic attempts to improve a feasible MIP solution by altering the solution values of pairs of
23  * variables. Only variables which share a pre-defined ratio of LP rows are considered as pairs. Each step of the
24  * heuristic consists of improving the objective value by shifting one variable, and then compensating the resulting
25  * infeasibilities by shifting a second variable, without completely losing the objective improvement. Similarly to
26  * Oneopt (see @ref heur_oneopt.h), pairs are processed in non-decreasing order of their impact on the objective.
27  */
28 
29 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
30 
31 #ifndef __SCIP_HEUR_TWOOPT_H__
32 #define __SCIP_HEUR_TWOOPT_H__
33 
34 
35 #include "scip/scip.h"
36 
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40 
41 /** creates the twoopt primal heuristic and includes it in SCIP */
42 extern
44  SCIP* scip /**< SCIP data structure */
45  );
46 
47 #ifdef __cplusplus
48 }
49 #endif
50 
51 #endif
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:53
SCIP_RETCODE SCIPincludeHeurTwoopt(SCIP *scip)
struct Scip SCIP
Definition: type_scip.h:30
SCIP callable library.