1    	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2    	/*                                                                           */
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4    	/*         SCIP --- Solving Constraint Integer Programs                      */
5    	/*                                                                           */
6    	/*  Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB)                      */
7    	/*                                                                           */
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22   	/*                                                                           */
23   	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24   	
25   	/**@file   objbenders.cpp
26   	 * @brief  C++ wrapper for the Benders' decomposition plugins
27   	 * @author Stephen J. Maher
28   	 */
29   	
30   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
31   	
32   	#include <cassert>
33   	
34   	#include "objbenders.h"
35   	
36   	
37   	
38   	
39   	/*
40   	 * Data structures
41   	 */
42   	
43   	/** Benders' decomposition data */
44   	struct SCIP_BendersData
45   	{
46   	   scip::ObjBenders*     objbenders;         /**< the Benders' decomposition object */
47   	   SCIP_Bool             deleteobject;       /**< should the Benders' decomposition object be deleted when benders is freed? */
48   	};
49   	
50   	
51   	
52   	
53   	/*
54   	 * Callback methods of the Benders' decomposition framework
55   	 */
56   	
57   	extern "C"
58   	{
59   	
60   	/** copy method for Benders' decomposition plugins (called when SCIP copies plugins) */
61   	static
62   	SCIP_DECL_BENDERSCOPY(bendersCopyObj)
63   	{  /*lint --e{715}*/
64   	   SCIP_BENDERSDATA* bendersdata;
65   	
66   	   assert(scip != NULL);
67   	
68   	   bendersdata = SCIPbendersGetData(benders);
69   	   assert(bendersdata != NULL);
70   	   assert(bendersdata->objbenders != NULL);
71   	   assert(bendersdata->objbenders->scip_ != scip);
72   	
73   	   if( bendersdata->objbenders->iscloneable() )
74   	   {
75   	      scip::ObjBenders* newobjbenders;
76   	      newobjbenders = dynamic_cast<scip::ObjBenders*> (bendersdata->objbenders->clone(scip));
77   	
78   	      /* call include method of Benders' decomposition object */
79   	      SCIP_CALL( SCIPincludeObjBenders(scip, newobjbenders, TRUE) );
80   	   }
81   	
82   	   return SCIP_OKAY;
83   	}
84   	
85   	/** destructor of Benders' decomposition to free user data (called when SCIP is exiting) */
86   	static
87   	SCIP_DECL_BENDERSFREE(bendersFreeObj)
88   	{  /*lint --e{715}*/
89   	   SCIP_BENDERSDATA* bendersdata;
90   	
91   	   bendersdata = SCIPbendersGetData(benders);
92   	   assert(bendersdata != NULL);
93   	   assert(bendersdata->objbenders != NULL);
94   	   assert(bendersdata->objbenders->scip_ == scip);
95   	
96   	   /* call virtual method of benders object */
97   	   SCIP_CALL( bendersdata->objbenders->scip_free(scip, benders) );
98   	
99   	   /* free benders object */
100  	   if( bendersdata->deleteobject )
101  	      delete bendersdata->objbenders;
102  	
103  	   /* free benders data */
104  	   delete bendersdata;
105  	   SCIPbendersSetData(benders, NULL); /*lint !e64*/
106  	
107  	   return SCIP_OKAY;
108  	}
109  	
110  	
111  	/** initialization method of Benders' decomposition (called after problem was transformed) */
112  	static
113  	SCIP_DECL_BENDERSINIT(bendersInitObj)
114  	{  /*lint --e{715}*/
115  	   SCIP_BENDERSDATA* bendersdata;
116  	
117  	   bendersdata = SCIPbendersGetData(benders);
118  	   assert(bendersdata != NULL);
119  	   assert(bendersdata->objbenders != NULL);
120  	   assert(bendersdata->objbenders->scip_ == scip);
121  	
122  	   /* call virtual method of benders object */
123  	   SCIP_CALL( bendersdata->objbenders->scip_init(scip, benders) );
124  	
125  	   return SCIP_OKAY;
126  	}
127  	
128  	
129  	/** deinitialization method of Benders' decomposition (called before transformed problem is freed) */
130  	static
131  	SCIP_DECL_BENDERSEXIT(bendersExitObj)
132  	{  /*lint --e{715}*/
133  	   SCIP_BENDERSDATA* bendersdata;
134  	
135  	   bendersdata = SCIPbendersGetData(benders);
136  	   assert(bendersdata != NULL);
137  	   assert(bendersdata->objbenders != NULL);
138  	
139  	   /* call virtual method of benders object */
140  	   SCIP_CALL( bendersdata->objbenders->scip_exit(scip, benders) );
141  	
142  	   return SCIP_OKAY;
143  	}
144  	
145  	
146  	/** presolving initialization method of Benders' decomposition (called when presolving is about to begin) */
147  	static
148  	SCIP_DECL_BENDERSINITPRE(bendersInitpreObj)
149  	{  /*lint --e{715}*/
150  	   SCIP_BENDERSDATA* bendersdata;
151  	
152  	   bendersdata = SCIPbendersGetData(benders);
153  	   assert(bendersdata != NULL);
154  	   assert(bendersdata->objbenders != NULL);
155  	
156  	   /* call virtual method of benders object */
157  	   SCIP_CALL( bendersdata->objbenders->scip_initpre(scip, benders) );
158  	
159  	   return SCIP_OKAY;
160  	}
161  	
162  	
163  	/** presolving deinitialization method of Benders' decomposition (called after presolving has been finished) */
164  	static
165  	SCIP_DECL_BENDERSEXITPRE(bendersExitpreObj)
166  	{  /*lint --e{715}*/
167  	   SCIP_BENDERSDATA* bendersdata;
168  	
169  	   bendersdata = SCIPbendersGetData(benders);
170  	   assert(bendersdata != NULL);
171  	   assert(bendersdata->objbenders != NULL);
172  	
173  	   /* call virtual method of benders object */
174  	   SCIP_CALL( bendersdata->objbenders->scip_exitpre(scip, benders) );
175  	
176  	   return SCIP_OKAY;
177  	}
178  	
179  	
180  	/** solving process initialization method of Benders' decomposition (called when branch and bound process is about to begin) */
181  	static
182  	SCIP_DECL_BENDERSINITSOL(bendersInitsolObj)
183  	{  /*lint --e{715}*/
184  	   SCIP_BENDERSDATA* bendersdata;
185  	
186  	   bendersdata = SCIPbendersGetData(benders);
187  	   assert(bendersdata != NULL);
188  	   assert(bendersdata->objbenders != NULL);
189  	
190  	   /* call virtual method of benders object */
191  	   SCIP_CALL( bendersdata->objbenders->scip_initsol(scip, benders) );
192  	
193  	   return SCIP_OKAY;
194  	}
195  	
196  	
197  	/** solving process deinitialization method of Benders' decomposition (called before branch and bound process data is freed) */
198  	static
199  	SCIP_DECL_BENDERSEXITSOL(bendersExitsolObj)
200  	{  /*lint --e{715}*/
201  	   SCIP_BENDERSDATA* bendersdata;
202  	
203  	   bendersdata = SCIPbendersGetData(benders);
204  	   assert(bendersdata != NULL);
205  	   assert(bendersdata->objbenders != NULL);
206  	
207  	   /* call virtual method of benders object */
208  	   SCIP_CALL( bendersdata->objbenders->scip_exitsol(scip, benders) );
209  	
210  	   return SCIP_OKAY;
211  	}
212  	
213  	
214  	/** method that is called to create the subproblem and register it with the Benders' decomposition structure. */
215  	static
216  	SCIP_DECL_BENDERSCREATESUB(bendersCreatesubObj)
217  	{  /*lint --e{715}*/
218  	   SCIP_BENDERSDATA* bendersdata;
219  	
220  	   bendersdata = SCIPbendersGetData(benders);
221  	   assert(bendersdata != NULL);
222  	   assert(bendersdata->objbenders != NULL);
223  	
224  	   /* call virtual method of benders object */
225  	   SCIP_CALL( bendersdata->objbenders->scip_createsub(scip, benders, probnumber) );
226  	
227  	   return SCIP_OKAY;
228  	}
229  	
230  	
231  	/** methods called prior to solving the subproblems */
232  	static
233  	SCIP_DECL_BENDERSPRESUBSOLVE(bendersPresubsolveObj)
234  	{  /*lint --e{715}*/
235  	   SCIP_BENDERSDATA* bendersdata;
236  	
237  	   bendersdata = SCIPbendersGetData(benders);
238  	   assert(bendersdata != NULL);
239  	   assert(bendersdata->objbenders != NULL);
240  	
241  	   /* call virtual method of benders object */
242  	   SCIP_CALL( bendersdata->objbenders->scip_presubsolve(scip, benders, sol, type, checkint, infeasible, auxviol,
243  	         skipsolve, result) );
244  	
245  	   return SCIP_OKAY;
246  	}
247  	
248  	
249  	/** method called to solve the convex relaxation of an individual subproblem of the Benders' decomposition */
250  	static
251  	SCIP_DECL_BENDERSSOLVESUBCONVEX(bendersSolvesubconvexObj)
252  	{  /*lint --e{715}*/
253  	   SCIP_BENDERSDATA* bendersdata;
254  	
255  	   bendersdata = SCIPbendersGetData(benders);
256  	   assert(bendersdata != NULL);
257  	   assert(bendersdata->objbenders != NULL);
258  	
259  	   /* call virtual method of benders object */
260  	   SCIP_CALL( bendersdata->objbenders->scip_solvesubconvex(scip, benders, sol, probnumber, onlyconvexcheck, objective,
261  	      result) );
262  	
263  	   return SCIP_OKAY;
264  	}
265  	
266  	
267  	/** method called to solve an individual subproblem of the Benders' decomposition */
268  	static
269  	SCIP_DECL_BENDERSSOLVESUB(bendersSolvesubObj)
270  	{  /*lint --e{715}*/
271  	   SCIP_BENDERSDATA* bendersdata;
272  	
273  	   bendersdata = SCIPbendersGetData(benders);
274  	   assert(bendersdata != NULL);
275  	   assert(bendersdata->objbenders != NULL);
276  	
277  	   /* call virtual method of benders object */
278  	   SCIP_CALL( bendersdata->objbenders->scip_solvesub(scip, benders, sol, probnumber, objective, result) );
279  	
280  	   return SCIP_OKAY;
281  	}
282  	
283  	
284  	/** method called after the subproblems are solved in the Benders' decomposition algorithm */
285  	static
286  	SCIP_DECL_BENDERSPOSTSOLVE(bendersPostsolveObj)
287  	{  /*lint --e{715}*/
288  	   SCIP_BENDERSDATA* bendersdata;
289  	
290  	   bendersdata = SCIPbendersGetData(benders);
291  	   assert(bendersdata != NULL);
292  	   assert(bendersdata->objbenders != NULL);
293  	
294  	   /* call virtual method of benders object */
295  	   SCIP_CALL( bendersdata->objbenders->scip_postsolve(scip, benders, sol, type, mergecands, npriomergecands,
296  	      nmergecands, checkint, infeasible, merged) );
297  	
298  	   return SCIP_OKAY;
299  	}
300  	
301  	
302  	/** frees an individual subproblem. Called in each iteration of the Benders' decomposition algorithm */
303  	static
304  	SCIP_DECL_BENDERSFREESUB(bendersFreesubObj)
305  	{  /*lint --e{715}*/
306  	   SCIP_BENDERSDATA* bendersdata;
307  	
308  	   bendersdata = SCIPbendersGetData(benders);
309  	   assert(bendersdata != NULL);
310  	   assert(bendersdata->objbenders != NULL);
311  	
312  	   /* call virtual method of benders object */
313  	   SCIP_CALL( bendersdata->objbenders->scip_freesub(scip, benders, probnumber) );
314  	
315  	   return SCIP_OKAY;
316  	}
317  	
318  	
319  	/** callback method to retrieve the master (subproblem) variable corresponding to the input subproblem (master) variable */
320  	static
321  	SCIP_DECL_BENDERSGETVAR(bendersGetvarObj)
322  	{  /*lint --e{715}*/
323  	   SCIP_BENDERSDATA* bendersdata;
324  	
325  	   bendersdata = SCIPbendersGetData(benders);
326  	   assert(bendersdata != NULL);
327  	   assert(bendersdata->objbenders != NULL);
328  	
329  	   /* call virtual method of benders object */
330  	   SCIP_CALL( bendersdata->objbenders->scip_getvar(scip, benders, var, mappedvar, probnumber) );
331  	
332  	   return SCIP_OKAY;
333  	}
334  	
335  	
336  	}
337  	
338  	
339  	/*
340  	 * Benders' decomposition specific interface methods
341  	 */
342  	
343  	/** creates the Benders' decomposition for the given Benders' decomposition object and includes it in SCIP */
344  	SCIP_RETCODE SCIPincludeObjBenders(
345  	   SCIP*                 scip,               /**< SCIP data structure */
346  	   scip::ObjBenders*     objbenders,         /**< Benders' decomposition object */
347  	   SCIP_Bool             deleteobject        /**< should the Benders' decomposition object be deleted when benders is freed? */
348  	   )
349  	{
350  	   SCIP_BENDERSDATA* bendersdata;
351  	
352  	   assert(scip != NULL);
353  	   assert(objbenders != NULL);
354  	   assert(objbenders->scip_ == scip);
355  	
356  	   /* create obj Benders' decomposition data */
357  	   bendersdata = new SCIP_BENDERSDATA;
358  	   bendersdata->objbenders = objbenders;
359  	   bendersdata->deleteobject = deleteobject;
360  	
361  	   /* include Benders' decomposition */
362  	   SCIP_CALL( SCIPincludeBenders(scip, objbenders->scip_name_, objbenders->scip_desc_,
363  	      objbenders->scip_priority_, objbenders->scip_cutlp_, objbenders->scip_cutpseudo_,
364  	      objbenders->scip_cutrelax_, objbenders->scip_shareauxvars_, bendersCopyObj, bendersFreeObj, bendersInitObj,
365  	      bendersExitObj, bendersInitpreObj, bendersExitpreObj, bendersInitsolObj, bendersExitsolObj, bendersGetvarObj,
366  	      bendersCreatesubObj, bendersPresubsolveObj, bendersSolvesubconvexObj, bendersSolvesubObj, bendersPostsolveObj,
367  	      bendersFreesubObj, bendersdata) ); /*lint !e429*/
368  	
369  	   return SCIP_OKAY; /*lint !e429*/
370  	}
371  	
372  	/** returns the benders object of the given name, or 0 if not existing */
373  	scip::ObjBenders* SCIPfindObjBenders(
374  	   SCIP*                 scip,               /**< SCIP data structure */
375  	   const char*           name                /**< name of Benders' decomposition */
376  	   )
377  	{
378  	   SCIP_BENDERS* benders;
379  	   SCIP_BENDERSDATA* bendersdata;
380  	
381  	   benders = SCIPfindBenders(scip, name);
382  	   if( benders == NULL )
383  	      return 0;
384  	
385  	   bendersdata = SCIPbendersGetData(benders);
386  	   assert(bendersdata != NULL);
387  	
388  	   return bendersdata->objbenders;
389  	}
390  	
391  	/** returns the benders object for the given Benders' decomposition */
392  	scip::ObjBenders* SCIPgetObjBenders(
393  	   SCIP*                 scip,               /**< SCIP data structure */
394  	   SCIP_BENDERS*         benders             /**< Benders' decomposition */
395  	   )
396  	{
397  	   SCIP_BENDERSDATA* bendersdata;
398  	
399  	   assert(scip != NULL);
400  	   bendersdata = SCIPbendersGetData(benders);
401  	   assert(bendersdata != NULL);
402  	
403  	   return bendersdata->objbenders;
404  	}
405