# SCIP

Solving Constraint Integer Programs

heur_actconsdiving.h
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
7 /* fuer Informationstechnik Berlin */
8 /* */
10 /* */
12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15
16 /**@file heur_actconsdiving.h
17  * @ingroup PRIMALHEURISTICS
18  * @brief LP diving heuristic that chooses fixings w.r.t. the active constraints the variable appear in
19  * @author Tobias Achterberg
20  *
21  * Diving heuristic: Iteratively fixes some fractional variable and resolves the LP-relaxation, thereby simulating a
22  * depth-first-search in the tree. Active Constraint Diving chooses a variable based on the active LP rows (equations
23  * are counted twice here). The variable score is calculated as a convex combination of the number of constraints the
24  * variable appears in, the sum of all positive coefficients and the absolute sum of all negative coefficients. The
25  * chosen variable is then rounded to the closest integer. One-level backtracking is applied: If the LP gets infeasible,
26  * the last fixings is undone, and the opposite fixing is tried. If this is infeasible, too, the procedure aborts.
27  */
28
29 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
30
31 #ifndef __SCIP_HEUR_ACTCONSDIVING_H__
32 #define __SCIP_HEUR_ACTCONSDIVING_H__
33
34 #include "scip/def.h"
35 #include "scip/type_retcode.h"
36 #include "scip/type_scip.h"
37
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41
42 /** creates the actconsdiving heuristic and includes it in SCIP
43  *
44  * @ingroup PrimalHeuristicIncludes
45  */
48  SCIP* scip /**< SCIP data structure */
49  );
50
51 #ifdef __cplusplus
52 }
53 #endif
54
55 #endif
SCIP_EXPORT SCIP_RETCODE SCIPincludeHeurActconsdiving(SCIP *scip)
#define SCIP_EXPORT
Definition: def.h:100
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:54
type definitions for return codes for SCIP methods
type definitions for SCIP&#39;s main datastructure
common defines and data types used in all packages of SCIP