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.         */
10   	/*  You may obtain a copy of the License at                                  */
11   	/*                                                                           */
12   	/*      http://www.apache.org/licenses/LICENSE-2.0                           */
13   	/*                                                                           */
14   	/*  Unless required by applicable law or agreed to in writing, software      */
15   	/*  distributed under the License is distributed on an "AS IS" BASIS,        */
16   	/*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17   	/*  See the License for the specific language governing permissions and      */
18   	/*  limitations under the License.                                           */
19   	/*                                                                           */
20   	/*  You should have received a copy of the Apache-2.0 license                */
21   	/*  along with SCIP; see the file LICENSE. If not visit scipopt.org.         */
22   	/*                                                                           */
23   	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24   	
25   	/**@file   heur_dualval.h
26   	 * @ingroup PRIMALHEURISTICS
27   	 * @brief  primal heuristic that uses dualvalues for successive switching variable values
28   	 * @author Tobias Buchwald
29   	 *
30   	 * This heuristic tries to find solutions by taking the LP or NLP, rounding solution values, fixing the variables to the
31   	 * rounded values and then changing some of the values.To determine which variable is changed we give each variable a
32   	 * ranking dependent on its dualvalue.  We work with a transformed problem that is always feasible and has objective = 0
33   	 * iff the original problem is also feasible. Thus we cannot expect to find really good solutions.
34   	 */
35   	
36   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
37   	
38   	#ifndef __SCIP_HEUR_DUALVAL_H__
39   	#define __SCIP_HEUR_DUALVAL_H__
40   	
41   	#include "scip/def.h"
42   	#include "scip/type_heur.h"
43   	#include "scip/type_result.h"
44   	#include "scip/type_retcode.h"
45   	#include "scip/type_scip.h"
46   	#include "scip/type_sol.h"
47   	
48   	#ifdef __cplusplus
49   	extern "C" {
50   	#endif
51   	
52   	/** creates the dualVal primal heuristic and includes it in SCIP
53   	 *
54   	 *  @ingroup PrimalHeuristicIncludes
55   	 */
56   	SCIP_EXPORT
57   	SCIP_RETCODE SCIPincludeHeurDualval(
58   	   SCIP*                 scip                /**< SCIP data structure */
59   	   );
60   	
61   	/**@addtogroup PRIMALHEURISTICS
62   	 *
63   	 * @{
64   	 */
65   	
66   	/** main procedure of the dualval heuristic */
67   	SCIP_EXPORT
68   	SCIP_RETCODE SCIPapplyHeurDualval(
69   	   SCIP*                 scip,               /**< original SCIP data structure */
70   	   SCIP_HEUR*            heur,               /**< heuristic data structure */
71   	   SCIP_RESULT*          result,             /**< pointer to store result of: did not run, solution found, no solution
72   	                                              *   found, or fixing is infeasible (cutoff) */
73   	   SCIP_SOL*             refpoint            /**< point to take fixation of discrete variables from; if NULL, then LP
74   	                                              *   solution is used */
75   	   );
76   	
77   	/** @} */
78   	
79   	#ifdef __cplusplus
80   	}
81   	#endif
82   	
83   	#endif
84