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2    	/*                                                                           */
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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");          */
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13   	/*                                                                           */
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19   	/*                                                                           */
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21   	/*  along with SCIP; see the file LICENSE. If not visit scipopt.org.         */
22   	/*                                                                           */
23   	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24   	
25   	/**@file   heur_rens.h
26   	 * @ingroup PRIMALHEURISTICS
27   	 * @brief  LNS heuristic that finds the optimal rounding to a given point
28   	 * @author Timo Berthold
29   	 *
30   	 * RENS is a large neighborhood search start heuristic, i.e., unlike other LNS heuristics, it does not need a known
31   	 * feasible solution. It solves a sub-SCIP that is created by fixing variables which take an integral value in a given
32   	 * LP or NLP solution. For the remaining integer variables, the bounds get tightened to the two nearest integral values.
33   	 */
34   	
35   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
36   	
37   	#ifndef __SCIP_HEUR_RENS_H__
38   	#define __SCIP_HEUR_RENS_H__
39   	
40   	#include "scip/def.h"
41   	#include "scip/type_heur.h"
42   	#include "scip/type_result.h"
43   	#include "scip/type_retcode.h"
44   	#include "scip/type_scip.h"
45   	
46   	#ifdef __cplusplus
47   	extern "C" {
48   	#endif
49   	
50   	/** creates RENS primal heuristic and includes it in SCIP
51   	 *
52   	 *  @ingroup PrimalHeuristicIncludes
53   	 */
54   	SCIP_EXPORT
55   	SCIP_RETCODE SCIPincludeHeurRens(
56   	   SCIP*                 scip                /**< SCIP data structure */
57   	   );
58   	
59   	/**@addtogroup PRIMALHEURISTICS
60   	 *
61   	 * @{
62   	 */
63   	
64   	/** main procedure of the RNS heuristic, creates and solves a sub-SCIP */
65   	SCIP_EXPORT
66   	SCIP_RETCODE SCIPapplyRens(
67   	   SCIP*                 scip,               /**< original SCIP data structure                                        */
68   	   SCIP_HEUR*            heur,               /**< heuristic data structure                                            */
69   	   SCIP_RESULT*          result,             /**< result data structure                                               */
70   	   SCIP_Real             minfixingrate,      /**< minimum percentage of integer variables that have to be fixed       */
71   	   SCIP_Real             minimprove,         /**< factor by which RENS should at least improve the incumbent          */
72   	   SCIP_Longint          maxnodes,           /**< maximum number of  nodes for the subproblem                         */
73   	   SCIP_Longint          nstallnodes,        /**< number of stalling nodes for the subproblem                         */
74   	   char                  startsol,           /**< solution used for fixing values ('l'p relaxation, 'n'lp relaxation) */
75   	   SCIP_Bool             binarybounds,       /**< should general integers get binary bounds [floor(.),ceil(.)]?       */
76   	   SCIP_Bool             uselprows           /**< should subproblem be created out of the rows in the LP rows?        */
77   	   );
78   	
79   	/** @} */
80   	
81   	#ifdef __cplusplus
82   	}
83   	#endif
84   	
85   	#endif
86