Scippy

GCG

Branch-and-Price & Column Generation for Everyone

heur_mastervecldiving.h
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program */
4 /* GCG --- Generic Column Generation */
5 /* a Dantzig-Wolfe decomposition based extension */
6 /* of the branch-cut-and-price framework */
7 /* SCIP --- Solving Constraint Integer Programs */
8 /* */
9 /* Copyright (C) 2010-2021 Operations Research, RWTH Aachen University */
10 /* Zuse Institute Berlin (ZIB) */
11 /* */
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13 /* modify it under the terms of the GNU Lesser General Public License */
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20 /* GNU Lesser General Public License for more details. */
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27 
28 /**@file heur_mastervecldiving.h
29  * @ingroup DIVINGHEURISTICS
30  * @brief master LP diving heuristic that rounds variables with long column vectors
31  * @author Tobias Achterberg
32  *
33  * Diving heuristic: Iteratively fixes some fractional variable and resolves the LP-relaxation, thereby simulating a
34  * depth-first-search in the tree. Vectorlength Diving chooses the variable with the smallest ratio of potential
35  * objective change and number of affected constraints and fixes it. One-level backtracking is applied: If the LP gets
36  * infeasible, the last fixings is undone, and the opposite fixing is tried. If this is infeasible, too, the procedure
37  * aborts.
38  */
39 
40 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
41 
42 #ifndef __SCIP_HEUR_MASTERVECLDIVING_H__
43 #define __SCIP_HEUR_MASTERVECLDIVING_H__
44 
45 
46 #include "scip/scip.h"
47 
48 #ifdef __cplusplus
49 extern "C" {
50 #endif
51 
52 /** creates the mastervecldiving heuristic and includes it in GCG */
53 SCIP_EXPORT
55  SCIP* scip /**< SCIP data structure */
56  );
57 
58 #ifdef __cplusplus
59 }
60 #endif
61 
62 #endif
SCIP_EXPORT SCIP_RETCODE GCGincludeHeurMastervecldiving(SCIP *scip)