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   scip_randnumgen.c
26   	 * @ingroup OTHER_CFILES
27   	 * @brief  public methods for random numbers
28   	 * @author Tobias Achterberg
29   	 * @author Timo Berthold
30   	 * @author Gerald Gamrath
31   	 * @author Leona Gottwald
32   	 * @author Stefan Heinz
33   	 * @author Gregor Hendel
34   	 * @author Thorsten Koch
35   	 * @author Alexander Martin
36   	 * @author Marc Pfetsch
37   	 * @author Michael Winkler
38   	 * @author Kati Wolter
39   	 *
40   	 * @todo check all SCIP_STAGE_* switches, and include the new stages TRANSFORMED and INITSOLVE
41   	 */
42   	
43   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
44   	
45   	#include "scip/misc.h"
46   	#include "scip/pub_message.h"
47   	#include "scip/scip_mem.h"
48   	#include "scip/scip_randnumgen.h"
49   	#include "scip/set.h"
50   	#include "scip/struct_scip.h"
51   	
52   	/** creates and initializes a random number generator
53   	 *
54   	 *  @note The initial seed is changed using SCIPinitializeRandomSeed()
55   	 */
56   	SCIP_RETCODE SCIPcreateRandom(
57   	   SCIP*                 scip,               /**< SCIP data structure */
58   	   SCIP_RANDNUMGEN**     randnumgen,         /**< random number generator */
59   	   unsigned int          initialseed,        /**< initial random seed */
60   	   SCIP_Bool             useglobalseed       /**< should the supplied seed be initialized by SCIP's global seed shift? */
61   	   )
62   	{
63   	   unsigned int modifiedseed;
64   	
65   	   assert(scip != NULL);
66   	   assert(randnumgen != NULL);
67   	
68   	   if( useglobalseed )
69   	      modifiedseed = SCIPinitializeRandomSeed(scip, initialseed);
70   	   else
71   	      modifiedseed = initialseed;
72   	
73   	   SCIP_CALL( SCIPrandomCreate(randnumgen, SCIPblkmem(scip), modifiedseed) );
74   	
75   	   return SCIP_OKAY;
76   	}
77   	
78   	/** frees a random number generator */
79   	void SCIPfreeRandom(
80   	   SCIP*                 scip,               /**< SCIP data structure */
81   	   SCIP_RANDNUMGEN**     randnumgen          /**< random number generator */
82   	   )
83   	{
84   	   assert(scip != NULL);
85   	   assert(randnumgen != NULL);
86   	
87   	   SCIPrandomFree(randnumgen, SCIPblkmem(scip));
88   	}
89   	
90   	/** initializes a random number generator with a given start seed
91   	 *
92   	 *  @note The seed is changed using SCIPinitializeRandomSeed()
93   	 */
94   	void SCIPsetRandomSeed(
95   	   SCIP*                 scip,               /**< SCIP data structure */
96   	   SCIP_RANDNUMGEN*      randnumgen,         /**< random number generator */
97   	   unsigned int          seed                /**< new random seed */
98   	   )
99   	{
100  	   unsigned int modifiedseed;
101  	
102  	   assert(scip != NULL);
103  	   assert(randnumgen != NULL);
104  	
105  	   modifiedseed = SCIPinitializeRandomSeed(scip, seed);
106  	
107  	   SCIPrandomSetSeed(randnumgen, modifiedseed);
108  	}
109  	
110  	/** modifies an initial seed value with the global shift of random seeds */
111  	unsigned int SCIPinitializeRandomSeed(
112  	   SCIP*                 scip,               /**< SCIP data structure */
113  	   unsigned int          initialseedvalue    /**< initial seed value to be modified */
114  	   )
115  	{
116  	   assert(scip != NULL);
117  	
118  	   return SCIPsetInitializeRandomSeed(scip->set, initialseedvalue);
119  	}
120