Scippy

SCIP

Solving Constraint Integer Programs

cons_components.c
Go to the documentation of this file.
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 cons_components.c
26  * @ingroup DEFPLUGINS_CONS
27  * @brief constraint handler for handling independent components
28  * @author Gerald Gamrath
29  *
30  * This constraint handler looks for independent components.
31  */
32 /*#define DETAILED_OUTPUT*/
33 /*#define SCIP_DEBUG*/
34 /*#define SCIP_MORE_DEBUG*/
35 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
36 
37 #include "blockmemshell/memory.h"
38 #include "scip/cons_components.h"
39 #include "scip/debug.h"
40 #include "scip/pub_cons.h"
41 #include "scip/pub_heur.h"
42 #include "scip/pub_message.h"
43 #include "scip/pub_misc.h"
44 #include "scip/pub_misc_sort.h"
45 #include "scip/pub_sol.h"
46 #include "scip/pub_tree.h"
47 #include "scip/pub_var.h"
48 #include "scip/scip_cons.h"
49 #include "scip/scip_copy.h"
51 #include "scip/scip_general.h"
52 #include "scip/scip_heur.h"
53 #include "scip/scip_mem.h"
54 #include "scip/scip_message.h"
55 #include "scip/scip_numerics.h"
56 #include "scip/scip_param.h"
57 #include "scip/scip_pricer.h"
58 #include "scip/scip_prob.h"
59 #include "scip/scip_probing.h"
60 #include "scip/scip_sol.h"
61 #include "scip/scip_solve.h"
62 #include "scip/scip_solvingstats.h"
63 #include "scip/scip_timing.h"
64 #include "scip/scip_tree.h"
65 #include "scip/scip_var.h"
66 #include <string.h>
67 
68 #define CONSHDLR_NAME "components"
69 #define CONSHDLR_DESC "independent components constraint handler"
70 #define CONSHDLR_ENFOPRIORITY 0 /**< priority of the constraint handler for constraint enforcing */
71 #define CONSHDLR_CHECKPRIORITY -9999999 /**< priority of the constraint handler for checking feasibility */
72 #define CONSHDLR_EAGERFREQ -1 /**< frequency for using all instead of only the useful constraints in separation,
73  * propagation and enforcement, -1 for no eager evaluations, 0 for first only */
74 #define CONSHDLR_NEEDSCONS FALSE /**< should the constraint handler be skipped, if no constraints are available? */
75 
76 #define CONSHDLR_PROPFREQ 1 /**< frequency for propagating domains; zero means only preprocessing propagation */
77 #define CONSHDLR_MAXPREROUNDS -1 /**< maximal number of presolving rounds the constraint handler participates in (-1: no limit) */
78 #define CONSHDLR_DELAYPROP TRUE /**< should propagation method be delayed, if other propagators found reductions? */
79 
80 #define CONSHDLR_PRESOLTIMING SCIP_PRESOLTIMING_FINAL /**< presolving timing of the constraint handler (fast, medium, or exhaustive) */
81 #define CONSHDLR_PROP_TIMING SCIP_PROPTIMING_BEFORELP /**< propagation timing mask of the constraint handler*/
82 
83 #define DEFAULT_MAXDEPTH -1 /**< maximum depth of a node to run components detection (-1: disable component detection during solving) */
84 #define DEFAULT_MAXINTVARS 500 /**< maximum number of integer (or binary) variables to solve a subproblem directly in presolving (-1: no solving) */
85 #define DEFAULT_MINSIZE 50 /**< minimum absolute size (in terms of variables) to solve a component individually during branch-and-bound */
86 #define DEFAULT_MINRELSIZE 0.1 /**< minimum relative size (in terms of variables) to solve a component individually during branch-and-bound */
87 #define DEFAULT_NODELIMIT 10000LL /**< maximum number of nodes to be solved in subproblems during presolving */
88 #define DEFAULT_INTFACTOR 1.0 /**< the weight of an integer variable compared to binary variables */
89 #define DEFAULT_FEASTOLFACTOR 1.0 /**< default value for parameter to increase the feasibility tolerance in all sub-SCIPs */
90 
91 /*
92  * Data structures
93  */
94 
95 /** data related to one problem (see below) */
96 typedef struct Problem PROBLEM;
97 
98 /** data related to one component */
99 typedef struct Component
100 {
101  PROBLEM* problem; /**< the problem this component belongs to */
102  SCIP* subscip; /**< sub-SCIP representing the component */
103  SCIP_SOL* workingsol; /**< working solution for transferring solutions into the sub-SCIP */
104  SCIP_VAR** vars; /**< variables belonging to this component (in complete problem) */
105  SCIP_VAR** subvars; /**< variables belonging to this component (in subscip) */
106  SCIP_VAR** fixedvars; /**< variables in the original SCIP which were copied while copying the component's
107  * constraints, but do not count to the subvars, because they were locally fixed */
108  SCIP_VAR** fixedsubvars; /**< variables in the sub-SCIP which were copied while copying the component's
109  * constraints, but do not count to the subvars, because they were locally fixed */
110  SCIP_Real fixedvarsobjsum; /**< objective contribution of all locally fixed variables */
111  SCIP_Real lastdualbound; /**< dual bound after last optimization call for this component */
112  SCIP_Real lastprimalbound; /**< primal bound after last optimization call for this component */
113  SCIP_STATUS laststatus; /**< solution status of last optimization call for the sub-SCIP of this component */
114  SCIP_Bool solved; /**< was this component solved already? */
115  int ncalls; /**< number of optimization calls for this component */
116  int lastsolindex; /**< index of best solution after last optimization call for this component */
117  int lastbestsolindex; /**< index of last best solution transferred to this component from the main problem */
118  int nvars; /**< number of variables belonging to this component */
119  int nfixedvars; /**< number of fixed variables copied during constraint copying */
120  int fixedvarssize; /**< size of fixedvars and fixedsubvars arrays */
121  int number; /**< component number */
123 
124 /** data related to one problem
125  * (corresponding to one node in the branch-and-bound tree and consisting of multiple components)
126  */
127 struct Problem
128 {
129  SCIP* scip; /**< the SCIP instance this problem belongs to */
130  COMPONENT* components; /**< independent components into which the problem can be divided */
131  SCIP_PQUEUE* compqueue; /**< priority queue for components */
132  SCIP_SOL* bestsol; /**< best solution found so far for the problem */
133  char* name; /**< name of the problem */
134  SCIP_Real fixedvarsobjsum; /**< objective contribution of all locally fixed variables */
135  SCIP_Real lowerbound; /**< lower bound of the problem */
136  int ncomponents; /**< number of independent components into which the problem can be divided */
137  int componentssize; /**< size of components array */
138  int nfeascomps; /**< number of components for which a feasible solution was found */
139  int nsolvedcomps; /**< number of components solved to optimality */
140  int nlowerboundinf; /**< number of components with lower bound equal to -infinity */
141 };
142 
143 
144 /** constraint handler data */
145 struct SCIP_ConshdlrData
146 {
147  SCIP_Longint nodelimit; /**< maximum number of nodes to be solved in subproblems */
148  SCIP_Real intfactor; /**< the weight of an integer variable compared to binary variables */
149  SCIP_Real feastolfactor; /**< parameter to increase the feasibility tolerance in all sub-SCIPs */
150  int maxintvars; /**< maximum number of integer (or binary) variables to solve a subproblem
151  * directly (-1: no solving) */
152  int maxdepth; /**< maximum depth of a node to run components detection (-1: disable
153  * component detection during solving) */
154  int minsize; /**< minimum absolute size (in terms of variables) to solve a component
155  * individually during branch-and-bound */
156  SCIP_Real minrelsize; /**< minimum relative size (in terms of variables) to solve a component
157  * individually during branch-and-bound */
158  int subscipdepth; /**< depth offset of the current (sub-)problem compared to the original
159  * problem */
160 };
161 
162 
163 /** comparison method for sorting components */
164 static
165 SCIP_DECL_SORTPTRCOMP(componentSort)
166 {
167  SCIP* scip;
168  COMPONENT* comp1;
169  COMPONENT* comp2;
170  SCIP_Real gap1;
171  SCIP_Real gap2;
172 
173  assert(elem1 != NULL);
174  assert(elem2 != NULL);
175 
176  comp1 = (COMPONENT*)elem1;
177  comp2 = (COMPONENT*)elem2;
178 
179  if( comp1->ncalls == 0 )
180  if( comp2->ncalls == 0 )
181  return comp1->number - comp2->number;
182  else
183  return -1;
184  else if( comp2->ncalls == 0 )
185  return 1;
186 
187  /* the main sorting criterion is the absolute gap; however, we devide it by the number of solving calls for this
188  * component to diversify the search if one component does not improve
189  * @todo investigate other sorting criteria
190  */
191  gap1 = SQR(comp1->lastprimalbound - comp1->lastdualbound) / comp1->ncalls;
192  gap2 = SQR(comp2->lastprimalbound - comp2->lastdualbound) / comp2->ncalls;
193 
194  assert(comp1->problem != NULL);
195  assert(comp1->problem == comp2->problem);
196  assert(comp1->problem->scip == comp2->problem->scip);
197 
198  scip = comp1->problem->scip;
199  assert(scip != NULL);
200 
201  if( SCIPisFeasGT(scip, gap1, gap2) )
202  return -1;
203  else if( SCIPisFeasLT(scip, gap1, gap2) )
204  return +1;
205  else
206  return comp1->number - comp2->number;
207 }
208 
209 /** returns minimum size of components to be solved individually during the branch-and-bound search */
210 static
211 int getMinsize(
212  SCIP* scip, /**< main SCIP data structure */
213  SCIP_CONSHDLRDATA* conshdlrdata /**< constraint handler data */
214  )
215 {
216  int minsize;
217 
218  assert(conshdlrdata != NULL);
219 
220  minsize = (int)(conshdlrdata->minrelsize * SCIPgetNVars(scip));
221  minsize = MAX(minsize, conshdlrdata->minsize);
222 
223  return minsize;
224 }
225 
226 /** initialize component structure */
227 static
229  PROBLEM* problem /**< subproblem structure */
230  )
231 {
232  COMPONENT* component;
233  SCIP* scip;
234 
235  assert(problem != NULL);
236  assert(problem->ncomponents < problem->componentssize);
237 
238  scip = problem->scip;
239  assert(scip != NULL);
240 
241  component = &problem->components[problem->ncomponents];
242 
243  component->problem = problem;
244  component->subscip = NULL;
245  component->workingsol = NULL;
246  component->vars = NULL;
247  component->subvars = NULL;
248  component->fixedvars = NULL;
249  component->fixedsubvars = NULL;
250  component->fixedvarsobjsum = 0.0;
251  component->lastdualbound = -SCIPinfinity(scip);
252  component->lastprimalbound = SCIPinfinity(scip);
253  component->laststatus = SCIP_STATUS_UNKNOWN;
254  component->solved = FALSE;
255  component->ncalls = 0;
256  component->lastsolindex = -1;
257  component->lastbestsolindex = -1;
258  component->nvars = 0;
259  component->nfixedvars = 0;
260  component->fixedvarssize = 0;
261  component->number = problem->ncomponents;
262 
263  ++problem->ncomponents;
264 
265  return SCIP_OKAY;
266 }
267 
268 /** free component structure */
269 static
271  COMPONENT* component /**< pointer to component structure */
272  )
273 {
274  PROBLEM* problem;
275  SCIP* scip;
276 
277  assert(component != NULL);
278 
279  problem = component->problem;
280  assert(problem != NULL);
281 
282  scip = problem->scip;
283  assert(scip != NULL);
284 
285  SCIPdebugMsg(scip, "freeing component %d of problem <%s>\n", component->number, component->problem->name);
286 
287  assert((component->vars != NULL) == (component->subvars != NULL));
288  if( component->vars != NULL )
289  {
290  SCIPfreeBlockMemoryArray(scip, &component->vars, component->nvars);
291  SCIPfreeBlockMemoryArray(scip, &component->subvars, component->nvars);
292  }
293 
294  assert((component->fixedvars != NULL) == (component->fixedsubvars != NULL));
295  if( component->fixedvars != NULL )
296  {
297  SCIPfreeBlockMemoryArray(scip, &component->fixedsubvars, component->fixedvarssize);
298  SCIPfreeBlockMemoryArray(scip, &component->fixedvars, component->fixedvarssize);
299  }
300 
301  /* free sub-SCIP belonging to this component and the working solution */
302  if( component->subscip != NULL )
303  {
304  if( component->workingsol != NULL )
305  {
306  SCIP_CALL( SCIPfreeSol(component->subscip, &component->workingsol) );
307  }
308 
309  SCIP_CALL( SCIPfree(&component->subscip) );
310  }
311 
312  return SCIP_OKAY;
313 }
314 
315 
316 /** create the working solution for a given component, store fixed variables and the corresponding objective offset */
317 static
319  COMPONENT* component, /**< component structure */
320  SCIP_HASHMAP* varmap /**< variable hashmap */
321  )
322 {
323  SCIP* subscip;
324 
325  assert(component != NULL);
326 
327  subscip = component->subscip;
328  assert(subscip != NULL);
329  assert(SCIPgetStage(subscip) == SCIP_STAGE_PROBLEM);
330 
331  /* the solution should live in the primal, not the origprimal, of the sub-SCIP, so we need to transform it first */
332  SCIP_CALL( SCIPtransformProb(subscip) );
333  SCIP_CALL( SCIPcreateOrigSol(subscip, &(component->workingsol), NULL) );
334 
335  /* the number of variables was increased by copying the constraints */
336  if( SCIPgetNOrigVars(subscip) > component->nvars )
337  {
338  PROBLEM* problem;
339  SCIP* scip;
340  SCIP_VAR** sourcevars;
341  SCIP_VAR* subvar;
342  int nsourcevars;
343  int nnewvars;
344  int idx = 0;
345  int nvars;
346  int v;
347 
348  problem = component->problem;
349  assert(problem != NULL);
350 
351  scip = problem->scip;
352  assert(scip != NULL);
353 
354  sourcevars = SCIPgetVars(scip);
355  nsourcevars = SCIPgetNVars(scip);
356  nnewvars = SCIPgetNOrigVars(subscip);
357  nvars = component->nvars;
358 
359  component->fixedvarssize = nnewvars - nvars;
360  SCIP_CALL( SCIPallocBlockMemoryArray(scip, &component->fixedvars, component->fixedvarssize) );
361  SCIP_CALL( SCIPallocBlockMemoryArray(scip, &component->fixedsubvars, component->fixedvarssize) );
362 
363  for( v = 0; v < nsourcevars; ++v )
364  {
365  subvar = (SCIP_VAR*)SCIPhashmapGetImage(varmap, sourcevars[v]);
366  if( subvar != NULL && SCIPvarGetIndex(subvar) >= nvars )
367  {
368  /* the variable is either locally fixed or could be an inactive variable present in a constraint
369  * for which an aggregation constraint linking it to the active variable was created in the subscip
370  */
371  assert(SCIPisZero(subscip, SCIPvarGetObj(subvar)) ||
372  SCIPisEQ(subscip, SCIPvarGetLbGlobal(subvar), SCIPvarGetUbGlobal(subvar)));
373 
374  /* variable is gloablly fixed in sub-SCIP, so it was locally fixed in the main-SCIP */
375  if( SCIPisEQ(subscip, SCIPvarGetLbGlobal(subvar), SCIPvarGetUbGlobal(subvar)) )
376  {
377  assert(SCIPisEQ(scip, SCIPvarGetLbLocal(sourcevars[v]), SCIPvarGetUbLocal(sourcevars[v])));
378 
379  component->fixedvarsobjsum += SCIPvarGetLbGlobal(subvar) * SCIPvarGetObj(subvar);
380  component->fixedvars[idx] = sourcevars[v];
381  component->fixedsubvars[idx] = subvar;
382  ++idx;
383 
384  SCIP_CALL( SCIPsetSolVal(subscip, component->workingsol, subvar, SCIPvarGetLbGlobal(subvar)) );
385  }
386  /* inactive variable */
387  else
388  {
389  assert(SCIPisZero(subscip, SCIPvarGetObj(subvar)));
390  }
391  }
392  else
393  {
394  assert(subvar == NULL || SCIPisLT(scip, SCIPvarGetLbGlobal(sourcevars[v]), SCIPvarGetUbGlobal(sourcevars[v])));
395  assert(subvar == NULL || SCIPisLT(subscip, SCIPvarGetLbGlobal(subvar), SCIPvarGetUbGlobal(subvar)));
396  }
397  }
398  component->nfixedvars = idx;
399  assert(component->nfixedvars <= component->fixedvarssize);
400  SCIPdebugMsg(scip, "%d locally fixed variables have been copied, objective contribution: %g\n",
401  component->nfixedvars, component->fixedvarsobjsum);
402  }
403 
404  /* set up debug solution */
405 #ifdef WITH_DEBUG_SOLUTION
406  if( SCIPdebugSolIsEnabled(component->problem->scip) )
407  {
408  PROBLEM* problem;
409  SCIP* scip;
410  SCIP_Bool isvalid = FALSE;
411 
412  problem = component->problem;
413  assert(problem != NULL);
414 
415  scip = problem->scip;
416  assert(scip != NULL);
417 
418  SCIP_CALL( SCIPdebugSolIsValidInSubtree(scip, &isvalid) );
419 
420  if( isvalid )
421  {
422  SCIP_Real val;
423  int i;
424 
425  SCIPdebugSolEnable(component->subscip);
426 
427  for( i = 0; i < component->nvars; ++i )
428  {
429  if( component->subvars[i] != NULL )
430  {
431  SCIP_CALL( SCIPdebugGetSolVal(scip, component->vars[i], &val) );
432  SCIP_CALL( SCIPdebugAddSolVal(component->subscip, component->subvars[i], val) );
433  }
434  }
435  for( i = 0; i < component->nfixedvars; ++i )
436  {
437  if( component->fixedsubvars[i] != NULL )
438  {
439  SCIP_CALL( SCIPdebugGetSolVal(scip, component->fixedvars[i], &val) );
440  SCIP_CALL( SCIPdebugAddSolVal(component->subscip, component->fixedsubvars[i], val) );
441  }
442  }
443  }
444  }
445 #endif
446 
447  return SCIP_OKAY;
448 }
449 
450 /** create a sub-SCIP for the given variables and constraints */
451 static
453  SCIP* scip, /**< main SCIP data structure */
454  SCIP_CONSHDLRDATA* conshdlrdata, /**< constraint handler data */
455  SCIP** subscip /**< pointer to store created sub-SCIP */
456  )
457 {
458  SCIP_Bool success;
459 
460  assert(conshdlrdata != NULL);
461 
462  /* create a new SCIP instance */
463  SCIP_CALL( SCIPcreate(subscip) );
464 
465  /* copy plugins, we omit pricers (because we do not run if there are active pricers) and dialogs */
466 #ifdef SCIP_MORE_DEBUG /* we print statistics later, so we need to copy statistics tables */
467  SCIP_CALL( SCIPcopyPlugins(scip, *subscip, TRUE, FALSE, TRUE, TRUE, TRUE, TRUE, TRUE,
468  TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, TRUE, TRUE, TRUE, TRUE, &success) );
469 #else
470  SCIP_CALL( SCIPcopyPlugins(scip, *subscip, TRUE, FALSE, TRUE, TRUE, TRUE, TRUE, TRUE,
471  TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, TRUE, TRUE, TRUE, &success) );
472 #endif
473 
474  /* the plugins were successfully copied */
475  if( success )
476  {
477  SCIP_CONSHDLR* newconshdlr;
478  SCIP_CONSHDLRDATA* newconshdlrdata;
479 #ifdef WITH_DEBUG_SOLUTION
480  SCIP_Bool isvalid = FALSE;
481 #endif
482 
483  /* copy parameter settings */
484  SCIP_CALL( SCIPcopyParamSettings(scip, *subscip) );
485 
486  /* some general settings should not be fixed */
487  assert(!SCIPisParamFixed(*subscip, "limits/solutions"));
488  assert(!SCIPisParamFixed(*subscip, "limits/bestsol"));
489  assert(!SCIPisParamFixed(*subscip, "misc/usevartable"));
490  assert(!SCIPisParamFixed(*subscip, "misc/useconstable"));
491  assert(!SCIPisParamFixed(*subscip, "numerics/feastol"));
492  assert(!SCIPisParamFixed(*subscip, "misc/usesmalltables"));
493 
494  /* disable solution limits */
495  SCIP_CALL( SCIPsetIntParam(*subscip, "limits/solutions", -1) );
496  SCIP_CALL( SCIPsetIntParam(*subscip, "limits/bestsol", -1) );
497 
498  /* reduce the effort spent for hash tables; however, if the debug solution is enabled and valid in this subtree,
499  * hash tables are needed for installing the debug solution
500  */
501 #ifdef WITH_DEBUG_SOLUTION
502  SCIP_CALL( SCIPdebugSolIsValidInSubtree(scip, &isvalid) );
503  if( !isvalid && SCIPgetStage(scip) > SCIP_STAGE_PRESOLVING )
504 #endif
505  {
506  SCIP_CALL( SCIPsetBoolParam(*subscip, "misc/usevartable", FALSE) );
507  SCIP_CALL( SCIPsetBoolParam(*subscip, "misc/useconstable", FALSE) );
508  }
509 
510  /* disable presolving */
512 
513  /* disable component presolving and fix the parameter */
514  SCIP_CALL( SCIPsetIntParam(*subscip, "constraints/" CONSHDLR_NAME "/maxprerounds", 0) );
515  SCIP_CALL( SCIPfixParam(*subscip, "constraints/" CONSHDLR_NAME "/maxprerounds") );
516 
517  /* find the components constraint handler in the sub-SCIP and inform it about the actual depth in the tree */
518  newconshdlr = SCIPfindConshdlr(*subscip, CONSHDLR_NAME);
519  assert(newconshdlr != NULL);
520 
521  newconshdlrdata = SCIPconshdlrGetData(newconshdlr);
522  assert(newconshdlrdata != NULL);
523  newconshdlrdata->subscipdepth = conshdlrdata->subscipdepth + SCIPgetDepth(scip);
524 
525  /* disable output, unless in extended debug mode */
526 #ifndef SCIP_MORE_DEBUG
527  SCIP_CALL( SCIPsetIntParam(*subscip, "display/verblevel", 0) );
528 #endif
529  }
530  else
531  {
532  SCIP_CALL( SCIPfree(subscip) );
533  *subscip = NULL;
534  }
535 
536  return SCIP_OKAY;
537 }
538 
539 /** copies the given variables and constraints to the given sub-SCIP */
540 static
542  SCIP* scip, /**< source SCIP */
543  SCIP* subscip, /**< target SCIP */
544  const char* name, /**< name for copied problem */
545  SCIP_VAR** vars, /**< array of variables to copy */
546  SCIP_VAR** subvars, /**< array to fill with copied vars */
547  SCIP_CONS** conss, /**< constraint to copy */
548  SCIP_HASHMAP* varmap, /**< hashmap used for the copy process of variables */
549  SCIP_HASHMAP* consmap, /**< hashmap used for the copy process of constraints */
550  int nvars, /**< number of variables to copy */
551  int nconss, /**< number of constraints to copy */
552  SCIP_Bool* success /**< pointer to store whether copying was successful */
553  )
554 {
555  SCIP_CONS* newcons;
556  int i;
557 
558  assert(scip != NULL);
559  assert(subscip != NULL);
560  assert(vars != NULL);
561  assert(subvars != NULL);
562  assert(conss != NULL);
563  assert(varmap != NULL);
564  assert(consmap != NULL);
565  assert(success != NULL);
566 
567  *success = TRUE;
568 
569  /* create problem in sub-SCIP */
570  SCIP_CALL( SCIPcopyProb(scip, subscip, varmap, consmap, FALSE, name) );
571 
572  /* copy variables */
573  for( i = 0; i < nvars; ++i )
574  {
575  SCIP_CALL( SCIPgetVarCopy(scip, subscip, vars[i], &subvars[i], varmap, consmap, FALSE, success) );
576 
577  /* abort if variable was not successfully copied */
578  if( !(*success) )
579  return SCIP_OKAY;
580  }
581 
582  /* copy constraints */
583  for( i = 0; i < nconss; ++i )
584  {
585  assert(!SCIPconsIsModifiable(conss[i]));
586 
587  /* copy the constraint */
588  SCIP_CALL( SCIPgetConsCopy(scip, subscip, conss[i], &newcons, SCIPconsGetHdlr(conss[i]), varmap, consmap, NULL,
589  SCIPconsIsInitial(conss[i]), SCIPconsIsSeparated(conss[i]), SCIPconsIsEnforced(conss[i]),
590  SCIPconsIsChecked(conss[i]), SCIPconsIsPropagated(conss[i]), FALSE, FALSE,
591  SCIPconsIsDynamic(conss[i]), SCIPconsIsRemovable(conss[i]), FALSE, FALSE, success) );
592 
593  /* abort if constraint was not successfully copied */
594  if( !(*success) )
595  return SCIP_OKAY;
596 
597  SCIP_CALL( SCIPaddCons(subscip, newcons) );
598  SCIP_CALL( SCIPreleaseCons(subscip, &newcons) );
599  }
600 
601  return SCIP_OKAY;
602 }
603 
604 /** create the sub-SCIP for a given component */
605 static
607  COMPONENT* component, /**< component structure */
608  SCIP_CONSHDLRDATA* conshdlrdata, /**< constraint handler data */
609  SCIP_HASHMAP* varmap, /**< variable hashmap used to improve performance */
610  SCIP_HASHMAP* consmap, /**< constraint hashmap used to improve performance */
611  SCIP_CONS** conss, /**< constraints contained in this component */
612  int nconss, /**< number of constraints contained in this component */
613  SCIP_Bool* success /**< pointer to store whether the copying process was successful */
614  )
615 {
616  char name[SCIP_MAXSTRLEN];
617  PROBLEM* problem;
618  SCIP* scip;
619  int minsize;
620 
621  assert(component != NULL);
622  assert(consmap != NULL);
623  assert(conss != NULL);
624  assert(success != NULL);
625  assert(component->nvars > 0);
626 
627  problem = component->problem;
628  assert(problem != NULL);
629 
630  scip = problem->scip;
631  assert(scip != NULL);
632 
633  (*success) = TRUE;
634 
635  SCIP_CALL( createSubscip(scip, conshdlrdata, &component->subscip) );
636 
637  if( component->subscip != NULL )
638  {
639  /* get minimum size of components to solve individually and set the parameter in the sub-SCIP */
640  minsize = getMinsize(scip, conshdlrdata);
641 
642  SCIP_CALL( SCIPsetIntParam(component->subscip, "constraints/" CONSHDLR_NAME "/minsize", minsize) );
643 
644  /* get name of the original problem and add "comp_nr" */
645  (void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "%s_comp_%d", problem->name, component->number);
646 
647  SCIP_CALL( copyToSubscip(scip, component->subscip, name, component->vars, component->subvars,
648  conss, varmap, consmap, component->nvars, nconss, success) );
649 
650  if( !(*success) )
651  {
652  SCIP_CALL( SCIPfree(&component->subscip) );
653  component->subscip = NULL;
654  }
655  }
656  else
657  (*success) = FALSE;
658 
659  return SCIP_OKAY;
660 }
661 
662 /** solve a given sub-SCIP up to the given limits */
663 static
665  SCIP* scip, /**< main SCIP */
666  SCIP* subscip, /**< sub-SCIP to solve */
667  SCIP_Longint nodelimit, /**< node limit */
668  SCIP_Real gaplimit /**< gap limit */
669  )
670 {
671  SCIP_Real timelimit;
672  SCIP_Real memorylimit;
673  SCIP_Bool avoidmemout;
674 
675  assert(scip != NULL);
676  assert(subscip != NULL);
677 
678  /* set time limit */
679  SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
680  if( !SCIPisInfinity(scip, timelimit) )
681  {
682  timelimit -= SCIPgetSolvingTime(scip);
683  timelimit += SCIPgetSolvingTime(subscip);
684  }
685 
686  /* substract the memory already used by the main SCIP and the estimated memory usage of external software */
687  /* @todo count memory of other components */
688  SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
689  if( !SCIPisInfinity(scip, memorylimit) )
690  {
691  memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
692  memorylimit -= SCIPgetMemExternEstim(scip)/1048576.0;
693  }
694 
695  /* check if mem limit needs to be avoided */
696  SCIP_CALL( SCIPgetBoolParam(scip, "misc/avoidmemout", &avoidmemout) );
697 
698  /* abort if no time is left or not enough memory (we don't abort in this case if misc_avoidmemout == TRUE)
699  * to create a copy of SCIP, including external memory usage */
700  if( avoidmemout && memorylimit <= 0.0 )
701  {
702  SCIPdebugMessage("--> not solved (not enough memory left)\n");
703  return SCIP_OKAY;
704  }
705  else if( timelimit <= 0.0 )
706  {
707  SCIPdebugMessage("--> not solved (not enough time left)\n");
708  return SCIP_OKAY;
709  }
710 
711  /* SCIP copy limits will set wrong time limits since it does not take into account time spent already in the
712  * sub-SCIP; nevertheless, we call it to set the memory limit and unset all other limits, if set in the main SCIP
713  */
714  SCIP_CALL( SCIPcopyLimits(scip, subscip) );
715 
716  /* set time and memory limit for the subproblem */
717  SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
718 
719  /* only set soft time limit if it exists */
720  if( SCIPgetParam(scip, "limits/softtime") != NULL )
721  {
722  SCIP_Real softtimelimit;
723 
724  /* set soft time limit, if specified in main SCIP and if it exists */
725  SCIP_CALL( SCIPgetRealParam(scip, "limits/softtime", &softtimelimit) );
726  if( softtimelimit > -0.5 )
727  {
728  softtimelimit -= SCIPgetSolvingTime(scip);
729  softtimelimit += SCIPgetSolvingTime(subscip);
730  softtimelimit = MAX(softtimelimit, 0.0);
731  }
732 
733  SCIP_CALL( SCIPsetRealParam(subscip, "limits/softtime", softtimelimit) );
734  }
735 
736  /* set gap limit */
737  SCIP_CALL( SCIPsetRealParam(subscip, "limits/gap", gaplimit) );
738 
739  /* set node limit */
740  SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit) );
741 
742  /* solve the subproblem */
743  SCIP_CALL( SCIPsolve(subscip) );
744 
745 #ifdef SCIP_MORE_DEBUG
746  SCIP_CALL( SCIPprintBestSol(subscip, NULL, FALSE) );
747  SCIP_CALL( SCIPprintStatistics(subscip, NULL) );
748 #endif
749 
750  return SCIP_OKAY;
751 }
752 
753 /** solve a connected component during presolving and evaluate the result */
754 static
756  SCIP* scip, /**< SCIP main data structure */
757  SCIP_CONSHDLRDATA* conshdlrdata, /**< the components constraint handler data */
758  SCIP* subscip, /**< sub-SCIP to be solved */
759  SCIP_VAR** vars, /**< array of variables copied to this component */
760  SCIP_VAR** subvars, /**< array of sub-SCIP variables corresponding to the vars array */
761  SCIP_CONS** conss, /**< array of constraints copied to this component */
762  int nvars, /**< number of variables copied to this component */
763  int nconss, /**< number of constraints copied to this component */
764  int* ndeletedconss, /**< pointer to store the number of deleted constraints */
765  int* nfixedvars, /**< pointer to store the number of fixed variables */
766  int* ntightenedbounds, /**< pointer to store the number of bound tightenings */
767  SCIP_RESULT* result, /**< pointer to store the result of the component solving */
768  SCIP_Bool* solved /**< pointer to store if the problem was solved to optimality */
769  )
770 {
771  int i;
772 
773  assert(scip != NULL);
774  assert(conshdlrdata != NULL);
775  assert(subscip != NULL);
776  assert(vars != NULL);
777  assert(conss != NULL);
778  assert(ndeletedconss != NULL);
779  assert(nfixedvars != NULL);
780  assert(ntightenedbounds != NULL);
781  assert(result != NULL);
782 
783  *solved = FALSE;
784 
785  SCIP_CALL( solveSubscip(scip, subscip, conshdlrdata->nodelimit, 0.0) );
786 
787  if( SCIPgetStatus(subscip) == SCIP_STATUS_OPTIMAL )
788  {
789  SCIP_SOL* sol;
790  SCIP_VAR* var;
791  SCIP_VAR* subvar;
792  SCIP_Real* fixvals;
793  SCIP_Bool feasible;
794  SCIP_Bool infeasible;
795  SCIP_Bool fixed;
796 
797  sol = SCIPgetBestSol(subscip);
798 
799 #ifdef SCIP_DEBUG
800  SCIP_CALL( SCIPcheckSolOrig(subscip, sol, &feasible, TRUE, TRUE) );
801 #else
802  SCIP_CALL( SCIPcheckSolOrig(subscip, sol, &feasible, FALSE, FALSE) );
803 #endif
804 
805  SCIPdebugMessage("--> solved to optimality: time=%.2f, solution is%s feasible\n", SCIPgetSolvingTime(subscip), feasible ? "" : " not");
806 
807  SCIP_CALL( SCIPallocBufferArray(scip, &fixvals, nvars) );
808 
809  if( feasible )
810  {
811  SCIP_Real glb;
812  SCIP_Real gub;
813 
814  /* get values of variables in the optimal solution */
815  for( i = 0; i < nvars; ++i )
816  {
817  var = vars[i];
818  subvar = subvars[i];
819 
820  /* get global bounds */
821  glb = SCIPvarGetLbGlobal(var);
822  gub = SCIPvarGetUbGlobal(var);
823 
824  if( subvar != NULL )
825  {
826  /* get solution value from optimal solution of the sub-SCIP */
827  fixvals[i] = SCIPgetSolVal(subscip, sol, subvar);
828 
829  assert(SCIPisFeasLE(scip, fixvals[i], SCIPvarGetUbLocal(var)));
830  assert(SCIPisFeasGE(scip, fixvals[i], SCIPvarGetLbLocal(var)));
831 
832  /* checking a solution is done with a relative tolerance of feasibility epsilon, if we really want to
833  * change the bounds of the variables by fixing them, the old bounds must not be violated by more than
834  * the absolute epsilon; therefore, we change the fixing values, if needed, and mark that the solution
835  * has to be checked again
836  */
837  if( SCIPisGT(scip, fixvals[i], gub) )
838  {
839  SCIPdebugMessage("variable <%s> fixval: %f violates global upperbound: %f\n",
840  SCIPvarGetName(var), fixvals[i], gub);
841  fixvals[i] = gub;
842  feasible = FALSE;
843  }
844  else if( SCIPisLT(scip, fixvals[i], glb) )
845  {
846  SCIPdebugMessage("variable <%s> fixval: %f violates global lowerbound: %f\n",
847  SCIPvarGetName(var), fixvals[i], glb);
848  fixvals[i] = glb;
849  feasible = FALSE;
850  }
851  assert(SCIPisLE(scip, fixvals[i], SCIPvarGetUbLocal(var)));
852  assert(SCIPisGE(scip, fixvals[i], SCIPvarGetLbLocal(var)));
853  }
854  else
855  {
856  /* the variable was not copied, so it was cancelled out of constraints during copying;
857  * thus, the variable is not constrained and we fix it to its best bound
858  */
859  if( SCIPisPositive(scip, SCIPvarGetObj(var)) )
860  fixvals[i] = glb;
861  else if( SCIPisNegative(scip, SCIPvarGetObj(var)) )
862  fixvals[i] = gub;
863  else
864  {
865  fixvals[i] = 0.0;
866  fixvals[i] = MIN(fixvals[i], gub);
867  fixvals[i] = MAX(fixvals[i], glb);
868  }
869  }
870  }
871 
872  /* the solution value of at least one variable is feasible with a relative tolerance of feasibility epsilon,
873  * but infeasible with an absolute tolerance of epsilon; try to set the variables to the bounds and check
874  * solution again in the original space (changing the values might now introduce infeasibilities of constraints)
875  */
876  if( !feasible )
877  {
878  SCIP_Real origobj;
879 
880  SCIPdebugMessage("solution violates bounds by more than epsilon, check the corrected solution...\n");
881 
882  origobj = SCIPgetSolOrigObj(subscip, SCIPgetBestSol(subscip));
883 
884  SCIP_CALL( SCIPfreeTransform(subscip) );
885 
886  SCIP_CALL( SCIPcreateOrigSol(subscip, &sol, NULL) );
887 
888  /* set solution values of variables */
889  for( i = 0; i < nvars; ++i )
890  {
891  if( subvars[i] != NULL )
892  {
893  SCIP_CALL( SCIPsetSolVal(subscip, sol, subvars[i], fixvals[i]) );
894  }
895  }
896 
897  /* check the solution; integrality and bounds should be fulfilled and do not have to be checked */
898  SCIP_CALL( SCIPcheckSol(subscip, sol, FALSE, FALSE, FALSE, FALSE, TRUE, &feasible) );
899 
900 #ifndef NDEBUG
901  /* in debug mode, we additionally check integrality and bounds */
902  if( feasible )
903  {
904  SCIP_CALL( SCIPcheckSol(subscip, sol, FALSE, FALSE, TRUE, TRUE, FALSE, &feasible) );
905  assert(feasible);
906  }
907 #endif
908 
909  SCIPdebugMessage("--> corrected solution is%s feasible\n", feasible ? "" : " not");
910 
911  if( !SCIPisFeasEQ(subscip, SCIPsolGetOrigObj(sol), origobj) )
912  {
913  SCIPdebugMessage("--> corrected solution has a different objective value (old=%16.9g, corrected=%16.9g)\n",
914  origobj, SCIPsolGetOrigObj(sol));
915 
916  feasible = FALSE;
917  }
918 
919  SCIP_CALL( SCIPfreeSol(subscip, &sol) );
920  }
921 
922  /* if the solution is feasible, fix variables and delete constraints of the component */
923  if( feasible )
924  {
925  /* fix variables */
926  for( i = 0; i < nvars; ++i )
927  {
928  assert(SCIPisLE(scip, fixvals[i], SCIPvarGetUbLocal(vars[i])));
929  assert(SCIPisGE(scip, fixvals[i], SCIPvarGetLbLocal(vars[i])));
930  assert(SCIPisLE(scip, fixvals[i], SCIPvarGetUbGlobal(vars[i])));
931  assert(SCIPisGE(scip, fixvals[i], SCIPvarGetLbGlobal(vars[i])));
932 
933  SCIP_CALL( SCIPfixVar(scip, vars[i], fixvals[i], &infeasible, &fixed) );
935  assert(!infeasible);
936  assert(fixed);
937  (*nfixedvars)++;
938  }
939 
940  /* delete constraints */
941  for( i = 0; i < nconss; ++i )
942  {
943  SCIP_CALL( SCIPdelCons(scip, conss[i]) );
944  (*ndeletedconss)++;
945  }
946 
947  *result = SCIP_SUCCESS;
948  *solved = TRUE;
949  }
950  }
951 
952  SCIPfreeBufferArray(scip, &fixvals);
953  }
954  else if( SCIPgetStatus(subscip) == SCIP_STATUS_INFEASIBLE )
955  {
956  *result = SCIP_CUTOFF;
957  }
958  else if( SCIPgetStatus(subscip) == SCIP_STATUS_UNBOUNDED || SCIPgetStatus(subscip) == SCIP_STATUS_INFORUNBD )
959  {
960  /* TODO: store unbounded ray in original SCIP data structure */
961  *result = SCIP_UNBOUNDED;
962  }
963  else
964  {
965  SCIPdebugMessage("--> solving interrupted (status=%d, time=%.2f)\n",
966  SCIPgetStatus(subscip), SCIPgetSolvingTime(subscip));
967 
968  /* transfer global fixings to the original problem; we can only do this, if we did not find a solution in the
969  * subproblem, because otherwise, the primal bound might lead to dual reductions that cannot be transferred to
970  * the original problem without also transferring the possibly suboptimal solution (which is currently not
971  * possible)
972  */
973  if( SCIPgetNSols(subscip) == 0 )
974  {
975  SCIP_Bool infeasible;
976  SCIP_Bool tightened;
977  int ntightened;
978 
979  ntightened = 0;
980 
981  for( i = 0; i < nvars; ++i )
982  {
983  if( subvars[i] == NULL )
984  continue;
985 
986  SCIP_CALL( SCIPtightenVarLb(scip, vars[i], SCIPvarGetLbGlobal(subvars[i]), FALSE,
987  &infeasible, &tightened) );
988  assert(!infeasible);
989  if( tightened )
990  ntightened++;
991 
992  SCIP_CALL( SCIPtightenVarUb(scip, vars[i], SCIPvarGetUbGlobal(subvars[i]), FALSE,
993  &infeasible, &tightened) );
994  assert(!infeasible);
995  if( tightened )
996  ntightened++;
997  }
998 
999  *result = SCIP_SUCCESS;
1000 
1001  *ntightenedbounds += ntightened;
1002 
1003  SCIPdebugMessage("--> tightened %d bounds of variables due to global bounds in the sub-SCIP\n", ntightened);
1004  }
1005  }
1006 
1007  return SCIP_OKAY;
1008 }
1009 
1010 /** (continues) solving a connected component */
1011 static
1013  COMPONENT* component, /**< component structure */
1014  SCIP_Bool lastcomponent, /**< is this the last component to be solved? */
1015  SCIP_RESULT* result /**< pointer to store the result of the solving process */
1016  )
1017 {
1018  PROBLEM* problem;
1019  SCIP* scip;
1020  SCIP* subscip;
1021  SCIP_SOL* bestsol;
1022  SCIP_Longint nodelimit;
1023  SCIP_Longint lastnnodes;
1024  SCIP_Real gaplimit;
1025  SCIP_STATUS status;
1026 
1027  assert(component != NULL);
1028 
1029  problem = component->problem;
1030  assert(problem != NULL);
1031 
1032  scip = problem->scip;
1033  assert(scip != NULL);
1034 
1035  subscip = component->subscip;
1036  assert(subscip != NULL);
1037 
1038  *result = SCIP_DIDNOTRUN;
1039 
1040  SCIPdebugMessage("solve component <%s> (ncalls=%d, absgap=%.9g)\n",
1041  SCIPgetProbName(subscip), component->ncalls, component->lastprimalbound - component->lastdualbound);
1042 
1043  bestsol = SCIPgetBestSol(scip);
1044 
1045  /* update best solution of component */
1046  if( bestsol != NULL && SCIPsolGetIndex(bestsol) != component->lastbestsolindex )
1047  {
1048  SCIP_SOL* compsol = component->workingsol;
1049  SCIP_VAR** vars = component->vars;
1050  SCIP_VAR** subvars = component->subvars;
1051  int nvars = component->nvars;
1052  int v;
1053 
1054  component->lastbestsolindex = SCIPsolGetIndex(bestsol);
1055 
1056  /* set solution values of component variables */
1057  for( v = 0; v < nvars; ++v )
1058  {
1059  if( subvars[v] != NULL )
1060  {
1061  SCIP_CALL( SCIPsetSolVal(subscip, compsol, subvars[v], SCIPgetSolVal(scip, bestsol, vars[v])) );
1062  }
1063  }
1064 #ifndef NDEBUG
1065  for( v = 0; v < component->nfixedvars; ++v )
1066  {
1067  if( component->fixedsubvars[v] != NULL )
1068  assert(SCIPisEQ(scip, SCIPgetSolVal(subscip, compsol, component->fixedsubvars[v]),
1069  SCIPvarGetLbGlobal(component->fixedsubvars[v])));
1070  }
1071 #endif
1072 
1073  if( SCIPgetStage(subscip) == SCIP_STAGE_PROBLEM
1074  || SCIPisLT(subscip, SCIPgetSolOrigObj(subscip, compsol), SCIPgetPrimalbound(subscip)) )
1075  {
1076  SCIP_Bool feasible;
1077 
1078  SCIPdebugMessage("checking new solution in component <%s> inherited from problem <%s>: primal bound %.9g --> %.9g\n",
1079  SCIPgetProbName(subscip), problem->name,
1080  SCIPgetStage(subscip) == SCIP_STAGE_PROBLEM ? SCIPinfinity(subscip) : SCIPgetPrimalbound(subscip),
1081  SCIPgetSolOrigObj(subscip, compsol));
1082 
1083  SCIP_CALL( SCIPcheckSolOrig(subscip, compsol, &feasible, FALSE, FALSE) );
1084  if( feasible )
1085  {
1086  SCIPdebugMessage("... feasible, adding solution.\n");
1087 
1088  SCIP_CALL( SCIPaddSol(subscip, compsol, &feasible) );
1089  }
1090 
1091  /* We cannot take the value of compsol as a cutoff bound if it was not feasible; some of the fixed connecting
1092  * variables are different and might not allow for a better solution in this component, but still for far
1093  * better solutions in other components. Therefore, the only cutoffbound we can apply is the cutoffbound
1094  * of the problem reduced by the dual bounds of the other components
1095  */
1096  if( problem->nlowerboundinf == 0 || (problem->nlowerboundinf == 1
1097  && SCIPisInfinity(scip, -component->lastdualbound)) )
1098  {
1099  SCIP_Real newcutoffbound = SCIPgetSolTransObj(scip, bestsol);
1100 
1101  assert(problem->nlowerboundinf > 0 || SCIPisGE(scip, newcutoffbound, problem->lowerbound));
1102 
1103  newcutoffbound = newcutoffbound - problem->lowerbound + component->fixedvarsobjsum;
1104 
1105  if( problem->nlowerboundinf == 0 )
1106  newcutoffbound += component->lastdualbound;
1107 
1108  if( SCIPisSumLT(subscip, newcutoffbound, SCIPgetCutoffbound(subscip)) )
1109  {
1110  SCIPdebugMessage("update cutoff bound to %16.9g\n", newcutoffbound);
1111 
1112  SCIP_CALL( SCIPupdateCutoffbound(subscip, newcutoffbound) );
1113  }
1114  }
1115  }
1116  }
1117 
1118  assert(component->laststatus != SCIP_STATUS_OPTIMAL);
1119 
1120  SCIPdebugMsg(scip, "solve sub-SCIP for component <%s> (ncalls=%d, absgap=%16.9g)\n",
1121  SCIPgetProbName(component->subscip), component->ncalls, component->lastprimalbound - component->lastdualbound);
1122 
1123  if( component->ncalls == 0 )
1124  {
1125  nodelimit = 1LL;
1126  gaplimit = 0.0;
1127 
1128  lastnnodes = 0;
1129  }
1130  else
1131  {
1132  SCIP_Longint mainnodelimit;
1133 
1134  lastnnodes = SCIPgetNNodes(component->subscip);
1135 
1136  SCIP_CALL( SCIPgetLongintParam(scip, "limits/nodes", &mainnodelimit) );
1137 
1138  nodelimit = 2 * lastnnodes;
1139  nodelimit = MAX(nodelimit, 10LL);
1140 
1141  if( mainnodelimit != -1 )
1142  {
1143  assert(mainnodelimit >= lastnnodes);
1144  nodelimit = MIN(nodelimit, mainnodelimit - lastnnodes);
1145  }
1146 
1147  /* set a gap limit of half the current gap (at most 10%) */
1148  if( SCIPgetGap(component->subscip) < 0.2 )
1149  gaplimit = 0.5 * SCIPgetGap(component->subscip);
1150  else
1151  gaplimit = 0.1;
1152 
1153  if( lastcomponent )
1154  gaplimit = 0.0;
1155  }
1156 
1157  SCIP_CALL( solveSubscip(scip, subscip, nodelimit, gaplimit) );
1158 
1159  SCIPaddNNodes(scip, SCIPgetNNodes(subscip) - lastnnodes);
1160 
1162 
1163  status = SCIPgetStatus(subscip);
1164 
1165  component->laststatus = status;
1166  ++component->ncalls;
1167 
1168  SCIPdebugMsg(scip, "--> (status=%d, nodes=%lld, time=%.2f): gap: %12.5g%% absgap: %16.9g\n",
1169  status, SCIPgetNNodes(subscip), SCIPgetSolvingTime(subscip), 100.0*SCIPgetGap(subscip),
1170  SCIPgetPrimalbound(subscip) - SCIPgetDualbound(subscip));
1171 
1172  *result = SCIP_SUCCESS;
1173 
1174  switch( status )
1175  {
1176  case SCIP_STATUS_OPTIMAL:
1177  component->solved = TRUE;
1178  break;
1180  component->solved = TRUE;
1181 
1182  /* the problem is really infeasible */
1183  if( SCIPisInfinity(subscip, SCIPgetPrimalbound(subscip)) )
1184  {
1185  *result = SCIP_CUTOFF;
1186  }
1187  /* the cutoff bound was reached; no solution better than the cutoff bound exists */
1188  else
1189  {
1190  *result = SCIP_SUCCESS;
1191  component->laststatus = SCIP_STATUS_OPTIMAL;
1192  assert(SCIPisLE(subscip, SCIPgetDualbound(subscip), SCIPgetPrimalbound(subscip)));
1193  }
1194  break;
1195  case SCIP_STATUS_UNBOUNDED:
1196  case SCIP_STATUS_INFORUNBD:
1197  /* TODO: store unbounded ray in original SCIP data structure */
1198  *result = SCIP_UNBOUNDED;
1199  component->solved = TRUE;
1200  break;
1202  SCIP_CALL( SCIPinterruptSolve(scip) );
1203  break;
1204  case SCIP_STATUS_TERMINATE:
1205  case SCIP_STATUS_UNKNOWN:
1206  case SCIP_STATUS_NODELIMIT:
1209  case SCIP_STATUS_TIMELIMIT:
1210  case SCIP_STATUS_MEMLIMIT:
1211  case SCIP_STATUS_GAPLIMIT:
1212  case SCIP_STATUS_SOLLIMIT:
1215  default:
1216  break;
1217  }
1218 
1219  /* evaluate call */
1220  if( *result == SCIP_SUCCESS )
1221  {
1222  SCIP_SOL* sol = SCIPgetBestSol(subscip);
1223  SCIP_VAR* var;
1224  SCIP_VAR* subvar;
1225  SCIP_Real newdualbound;
1226  int v;
1227 
1228  /* get dual bound as the minimum of SCIP dual bound and sub-problems dual bound */
1229  newdualbound = SCIPgetDualbound(subscip) - component->fixedvarsobjsum;
1230 
1231  /* update dual bound of problem */
1232  if( !SCIPisEQ(scip, component->lastdualbound, newdualbound) )
1233  {
1234  assert(!SCIPisInfinity(scip, -newdualbound));
1235 
1236  /* first finite dual bound: decrease inf counter and add dual bound to problem dualbound */
1237  if( SCIPisInfinity(scip, -component->lastdualbound) )
1238  {
1239  --problem->nlowerboundinf;
1240  problem->lowerbound += newdualbound;
1241  }
1242  /* increase problem dual bound by dual bound delta */
1243  else
1244  {
1245  problem->lowerbound += (newdualbound - component->lastdualbound);
1246  }
1247 
1248  /* update problem dual bound if all problem components have a finite dual bound */
1249  if( problem->nlowerboundinf == 0 )
1250  {
1251  SCIPdebugMessage("component <%s>: dual bound increased from %16.9g to %16.9g, new dual bound of problem <%s>: %16.9g (gap: %16.9g, absgap: %16.9g)\n",
1252  SCIPgetProbName(subscip), component->lastdualbound, newdualbound, problem->name,
1253  SCIPretransformObj(scip, problem->lowerbound),
1254  problem->nfeascomps == problem->ncomponents ?
1255  (SCIPgetSolOrigObj(scip, problem->bestsol) - SCIPretransformObj(scip, problem->lowerbound)) /
1256  MAX( ABS( SCIPretransformObj(scip, problem->lowerbound) ), SCIPgetSolOrigObj(scip, problem->bestsol) ) /*lint !e666*/
1257  : SCIPinfinity(scip),
1258  problem->nfeascomps == problem->ncomponents ?
1259  SCIPgetSolOrigObj(scip, problem->bestsol) - SCIPretransformObj(scip, problem->lowerbound) : SCIPinfinity(scip));
1260  SCIP_CALL( SCIPupdateLocalLowerbound(scip, problem->lowerbound) );
1261  }
1262 
1263  /* store dual bound of this call */
1264  component->lastdualbound = newdualbound;
1265  }
1266 
1267  /* update primal solution of problem */
1268  if( sol != NULL && component->lastsolindex != SCIPsolGetIndex(sol) )
1269  {
1270  component->lastsolindex = SCIPsolGetIndex(sol);
1271 
1272  if( SCIPsolGetHeur(sol) != NULL )
1274  else
1275  SCIPsolSetHeur(problem->bestsol, NULL);
1276 
1277  /* increase counter for feasible problems if no solution was known before */
1278  if( SCIPisInfinity(scip, component->lastprimalbound) )
1279  ++(problem->nfeascomps);
1280 
1281  /* update working best solution in problem */
1282  for( v = 0; v < component->nvars; ++v )
1283  {
1284  var = component->vars[v];
1285  subvar = component->subvars[v];
1286  assert(var != NULL);
1287  assert(SCIPvarIsActive(var));
1288 
1289  if( subvar == NULL )
1290  continue;
1291 
1292  SCIP_CALL( SCIPsetSolVal(scip, problem->bestsol, var, SCIPgetSolVal(subscip, sol, subvar)) );
1293  }
1294 
1295  /* if we have a feasible solution for each component, add the working solution to the main problem */
1296  if( problem->nfeascomps == problem->ncomponents )
1297  {
1298  SCIP_Bool feasible;
1299 #ifdef SCIP_MORE_DEBUG
1300  SCIP_CALL( SCIPcheckSol(scip, problem->bestsol, TRUE, FALSE, TRUE, TRUE, TRUE, &feasible) );
1301  assert(feasible);
1302 #endif
1303  SCIP_CALL( SCIPaddSol(scip, problem->bestsol, &feasible) );
1304 
1305  SCIPdebugMessage("component <%s>: primal bound decreased from %16.9g to %16.9g, new primal bound of problem <%s>: %16.9g (gap: %16.9g, absgap: %16.9g)\n",
1306  SCIPgetProbName(subscip), component->lastprimalbound, SCIPgetPrimalbound(subscip), problem->name,
1307  SCIPgetSolOrigObj(scip, problem->bestsol),
1308  problem->nfeascomps == problem->ncomponents ?
1309  (SCIPgetSolOrigObj(scip, problem->bestsol) - SCIPretransformObj(scip, problem->lowerbound)) /
1310  MAX( ABS( SCIPretransformObj(scip, problem->lowerbound) ),SCIPgetSolOrigObj(scip, problem->bestsol) ) /*lint !e666*/
1311  : SCIPinfinity(scip),
1312  problem->nfeascomps == problem->ncomponents ?
1313  SCIPgetSolOrigObj(scip, problem->bestsol) - SCIPretransformObj(scip, problem->lowerbound) : SCIPinfinity(scip));
1314  }
1315 
1316  /* store primal bound of this call */
1317  component->lastprimalbound = SCIPgetPrimalbound(subscip) - component->fixedvarsobjsum;
1318  }
1319 
1320  /* if the component was solved to optimality, we increase the respective counter and free the subscip */
1321  if( component->laststatus == SCIP_STATUS_OPTIMAL || component->laststatus == SCIP_STATUS_INFEASIBLE ||
1322  component->laststatus == SCIP_STATUS_UNBOUNDED || component->laststatus == SCIP_STATUS_INFORUNBD )
1323  {
1324  ++(problem->nsolvedcomps);
1325  component->solved = TRUE;
1326 
1327  /* free working solution and component */
1328  SCIP_CALL( SCIPfreeSol(subscip, &component->workingsol) );
1329 
1330  SCIP_CALL( SCIPfree(&subscip) );
1331  component->subscip = NULL;
1332  }
1333  }
1334 
1335  return SCIP_OKAY;
1336 }
1337 
1338 /** initialize subproblem structure */
1339 static
1341  SCIP* scip, /**< SCIP data structure */
1342  PROBLEM** problem, /**< pointer to subproblem structure */
1343  SCIP_Real fixedvarsobjsum, /**< objective contribution of all locally fixed variables */
1344  int ncomponents /**< number of independent components */
1345  )
1346 {
1347  char name[SCIP_MAXSTRLEN];
1348  SCIP_VAR** vars;
1349  int nvars;
1350  int v;
1351 
1352  assert(scip != NULL);
1353  assert(problem != NULL);
1354 
1355  vars = SCIPgetVars(scip);
1356  nvars = SCIPgetNVars(scip);
1357 
1359  assert(*problem != NULL);
1360 
1361  SCIP_CALL( SCIPallocBlockMemoryArray(scip, &(*problem)->components, ncomponents) );
1362 
1363  /* create a priority queue for the components: we need exactly ncomponents slots in the queue so it should never be
1364  * resized
1365  */
1366  SCIP_CALL( SCIPpqueueCreate(&(*problem)->compqueue, ncomponents, 1.2, componentSort, NULL) );
1367 
1368  (*problem)->scip = scip;
1369  (*problem)->lowerbound = fixedvarsobjsum;
1370  (*problem)->fixedvarsobjsum = fixedvarsobjsum;
1371  (*problem)->ncomponents = 0;
1372  (*problem)->componentssize = ncomponents;
1373  (*problem)->nlowerboundinf = ncomponents;
1374  (*problem)->nfeascomps = 0;
1375  (*problem)->nsolvedcomps = 0;
1376 
1377  if( SCIPgetDepth(scip) == 0 )
1378  (void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "%s", SCIPgetProbName(scip));
1379  else
1380  (void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "%s_node_%" SCIP_LONGINT_FORMAT, SCIPgetProbName(scip), SCIPnodeGetNumber(SCIPgetCurrentNode(scip)));
1381 
1382  SCIP_CALL( SCIPduplicateMemoryArray(scip, &(*problem)->name, name, strlen(name)+1) );
1383 
1384  SCIP_CALL( SCIPcreateSol(scip, &(*problem)->bestsol, NULL) );
1385 
1386  for( v = 0; v < nvars; v++ )
1387  {
1388  if( SCIPisFeasEQ(scip, SCIPvarGetLbLocal(vars[v]), SCIPvarGetUbLocal(vars[v])) )
1389  {
1390  SCIP_CALL( SCIPsetSolVal(scip, (*problem)->bestsol, vars[v],
1391  (SCIPvarGetUbLocal(vars[v]) + SCIPvarGetLbLocal(vars[v]))/2) );
1392  }
1393  }
1394 
1395  SCIPdebugMessage("initialized problem <%s>\n", (*problem)->name);
1396 
1397  return SCIP_OKAY;
1398 }
1399 
1400 /** free subproblem structure */
1401 static
1403  PROBLEM** problem /**< pointer to problem to free */
1404  )
1405 {
1406  SCIP* scip;
1407  int c;
1408 
1409  assert(problem != NULL);
1410  assert(*problem != NULL);
1411 
1412  scip = (*problem)->scip;
1413  assert(scip != NULL);
1414 
1415  /* free best solution */
1416  if( (*problem)->bestsol != NULL )
1417  {
1418  SCIP_CALL( SCIPfreeSol(scip, &(*problem)->bestsol) );
1419  }
1420 
1421  /* free all components */
1422  for( c = (*problem)->ncomponents - 1; c >= 0; --c )
1423  {
1424  SCIP_CALL( freeComponent(&(*problem)->components[c]) );
1425  }
1426  if( (*problem)->components != NULL )
1427  {
1428  SCIPfreeBlockMemoryArray(scip, &(*problem)->components, (*problem)->componentssize);
1429  }
1430 
1431  /* free priority queue */
1432  SCIPpqueueFree(&(*problem)->compqueue);
1433 
1434  /* free problem name */
1435  SCIPfreeMemoryArray(scip, &(*problem)->name);
1436 
1437  /* free PROBLEM struct and set the pointer to NULL */
1439  *problem = NULL;
1440 
1441  return SCIP_OKAY;
1442 }
1443 
1444 /** creates and captures a components constraint */
1445 static
1447  SCIP* scip, /**< SCIP data structure */
1448  SCIP_CONS** cons, /**< pointer to hold the created constraint */
1449  const char* name, /**< name of constraint */
1450  PROBLEM* problem /**< problem to be stored in the constraint */
1451  )
1452 {
1453  SCIP_CONSHDLR* conshdlr;
1454 
1455  /* find the samediff constraint handler */
1456  conshdlr = SCIPfindConshdlr(scip, CONSHDLR_NAME);
1457  if( conshdlr == NULL )
1458  {
1459  SCIPerrorMessage("components constraint handler not found\n");
1460  return SCIP_PLUGINNOTFOUND;
1461  }
1462 
1463  /* create constraint */
1464  SCIP_CALL( SCIPcreateCons(scip, cons, name, conshdlr, (SCIP_CONSDATA*)problem,
1465  FALSE, FALSE, FALSE, FALSE, TRUE,
1466  TRUE, FALSE, FALSE, FALSE, TRUE) );
1467 
1468  return SCIP_OKAY;
1469 }
1470 
1471 
1472 /** sort the components by size and sort vars and conss arrays by component numbers */
1473 static
1475  SCIP* scip, /**< SCIP data structure */
1476  SCIP_CONSHDLRDATA* conshdlrdata, /**< constraint handler data */
1477  SCIP_DIGRAPH* digraph, /**< directed graph */
1478  SCIP_CONS** conss, /**< constraints */
1479  SCIP_VAR** vars, /**< variables */
1480  int* varcomponent, /**< component numbers for the variables */
1481  int* conscomponent, /**< array to store component numbers for the constraints */
1482  int nconss, /**< number of constraints */
1483  int nvars, /**< number of variables */
1484  int* firstvaridxpercons, /**< array with index of first variable in vars array for each constraint */
1485  int* ncompsminsize, /**< pointer to store the number of components not exceeding the minimum size */
1486  int* ncompsmaxsize /**< pointer to store the number of components not exceeding the maximum size */
1487  )
1488 {
1489  SCIP_Real* compsize;
1490  int* permu;
1491  int ncomponents;
1492  int nbinvars;
1493  int nintvars;
1494  int ndiscvars;
1495  int ncontvars;
1496  int minsize;
1497  int v;
1498  int c;
1499 
1500  assert(scip != NULL);
1501  assert(conshdlrdata != NULL);
1502  assert(digraph != NULL);
1503  assert(conss != NULL);
1504  assert(vars != NULL);
1505  assert(firstvaridxpercons != NULL);
1506 
1507  /* compute minimum size of components to solve individually */
1508  minsize = getMinsize(scip, conshdlrdata);
1509 
1510  ncomponents = SCIPdigraphGetNComponents(digraph);
1511  *ncompsminsize = 0;
1512  *ncompsmaxsize = 0;
1513 
1514  /* We want to sort the components in increasing complexity (number of discrete variables,
1515  * integer weighted with factor intfactor, continuous used as tie-breaker).
1516  * Therefore, we now get the variables for each component, count the different variable types
1517  * and compute a size as described above. Then, we rename the components
1518  * such that for i < j, component i has no higher complexity than component j.
1519  */
1520  SCIP_CALL( SCIPallocBufferArray(scip, &compsize, ncomponents) );
1521  SCIP_CALL( SCIPallocBufferArray(scip, &permu, ncomponents) );
1522 
1523  /* get number of variables in the components */
1524  for( c = 0; c < ncomponents; ++c )
1525  {
1526  int* cvars;
1527  int ncvars;
1528 
1529  SCIPdigraphGetComponent(digraph, c, &cvars, &ncvars);
1530  permu[c] = c;
1531  nbinvars = 0;
1532  nintvars = 0;
1533 
1534  for( v = 0; v < ncvars; ++v )
1535  {
1536  /* check whether variable is of binary or integer type */
1537  if( SCIPvarGetType(vars[cvars[v]]) == SCIP_VARTYPE_BINARY )
1538  nbinvars++;
1539  else if( SCIPvarGetType(vars[cvars[v]]) == SCIP_VARTYPE_INTEGER )
1540  nintvars++;
1541  }
1542  ncontvars = ncvars - nintvars - nbinvars;
1543  ndiscvars = (int)(nbinvars + conshdlrdata->intfactor * nintvars);
1544  compsize[c] = ((1000.0 * ndiscvars + (950.0 * ncontvars)/nvars));
1545 
1546  /* component fulfills the maxsize requirement */
1547  if( ndiscvars <= conshdlrdata->maxintvars )
1548  ++(*ncompsmaxsize);
1549 
1550  /* component fulfills the minsize requirement */
1551  if( ncvars >= minsize )
1552  ++(*ncompsminsize);
1553  }
1554 
1555  /* get permutation of component numbers such that the size of the components is increasing */
1556  SCIPsortRealInt(compsize, permu, ncomponents);
1557 
1558  /* now, we need the reverse direction, i.e., for each component number, we store its new number
1559  * such that the components are sorted; for this, we abuse the conscomponent array
1560  */
1561  for( c = 0; c < ncomponents; ++c )
1562  conscomponent[permu[c]] = c;
1563 
1564  /* for each variable, replace the old component number by the new one */
1565  for( c = 0; c < nvars; ++c )
1566  varcomponent[c] = conscomponent[varcomponent[c]];
1567 
1568  SCIPfreeBufferArray(scip, &permu);
1569  SCIPfreeBufferArray(scip, &compsize);
1570 
1571  /* do the mapping from calculated components per variable to corresponding
1572  * constraints and sort the component-arrays for faster finding the
1573  * actual variables and constraints belonging to one component
1574  */
1575  for( c = 0; c < nconss; c++ )
1576  conscomponent[c] = (firstvaridxpercons[c] == -1 ? -1 : varcomponent[firstvaridxpercons[c]]);
1577 
1578  SCIPsortIntPtr(varcomponent, (void**)vars, nvars);
1579  SCIPsortIntPtr(conscomponent, (void**)conss, nconss);
1580 
1581  return SCIP_OKAY;
1582 }
1583 
1584 
1585 
1586 /** create PROBLEM structure for the current node and split it into components */
1587 static
1589  SCIP* scip, /**< SCIP data structure */
1590  SCIP_CONSHDLRDATA* conshdlrdata, /**< constraint handler data */
1591  SCIP_Real fixedvarsobjsum, /**< objective contribution of all locally fixed variables */
1592  SCIP_VAR** sortedvars, /**< array of unfixed variables sorted by components */
1593  SCIP_CONS** sortedconss, /**< array of (checked) constraints sorted by components */
1594  int* compstartsvars, /**< start points of components in sortedvars array */
1595  int* compstartsconss, /**< start points of components in sortedconss array */
1596  int ncomponents, /**< number of components */
1597  PROBLEM** problem /**< pointer to store problem structure */
1598  )
1599 {
1600  COMPONENT* component;
1601  SCIP_HASHMAP* consmap;
1602  SCIP_HASHMAP* varmap;
1603  SCIP_VAR** compvars;
1604  SCIP_CONS** compconss;
1605  SCIP_Bool success = TRUE;
1606  int nfixedvars = SCIPgetNVars(scip) - compstartsvars[ncomponents];
1607  int ncompconss;
1608  int comp;
1609 
1610  /* init subproblem data structure */
1611  SCIP_CALL( initProblem(scip, problem, fixedvarsobjsum, ncomponents) );
1612  assert((*problem)->components != NULL);
1613 
1614  /* hashmap mapping from original constraints to constraints in the sub-SCIPs (for performance reasons) */
1615  SCIP_CALL( SCIPhashmapCreate(&consmap, SCIPblkmem(scip), compstartsconss[ncomponents]) );
1616 
1617  /* loop over all components */
1618  for( comp = 0; comp < ncomponents; comp++ )
1619  {
1621  assert((*problem)->ncomponents == comp+1);
1622 
1623  component = &(*problem)->components[comp];
1624 
1625  /* get component variables and store them in component structure */
1626  compvars = &(sortedvars[compstartsvars[comp]]);
1627  component->nvars = compstartsvars[comp + 1 ] - compstartsvars[comp];
1628  SCIP_CALL( SCIPduplicateBlockMemoryArray(scip, &component->vars, compvars, component->nvars) );
1629  SCIP_CALL( SCIPallocBlockMemoryArray(scip, &component->subvars, component->nvars) );
1630  SCIP_CALL( SCIPhashmapCreate(&varmap, SCIPblkmem(scip), component->nvars + nfixedvars) );
1631 
1632  /* get component constraints */
1633  compconss = &(sortedconss[compstartsconss[comp]]);
1634  ncompconss = compstartsconss[comp + 1] - compstartsconss[comp];
1635 
1636 #ifdef DETAILED_OUTPUT
1637  /* print details about the component including its size */
1638  if( component->nvars > 1 && ncompconss > 1 )
1639  {
1640  int nbinvars = 0;
1641  int nintvars = 0;
1642  int ncontvars = 0;
1643  int i;
1644 
1645  for( i = 0; i < component->nvars; ++i )
1646  {
1647  if( SCIPvarGetType(compvars[i]) == SCIP_VARTYPE_BINARY )
1648  ++nbinvars;
1649  else if( SCIPvarGetType(compvars[i]) == SCIP_VARTYPE_INTEGER )
1650  ++nintvars;
1651  else
1652  ++ncontvars;
1653  }
1654  SCIPdebugMsg(scip, "component %d at node %lld, depth %d (%d): %d vars (%d bin, %d int, %d cont), %d conss\n",
1655  comp, SCIPnodeGetNumber(SCIPgetCurrentNode(scip)), SCIPgetDepth(scip), SCIPgetDepth(scip) + conshdlrdata->subscipdepth,
1656  component->nvars, nbinvars, nintvars, ncontvars, ncompconss);
1657  }
1658 #endif
1659  assert(ncompconss > 0 || component->nvars == 1);
1660 
1661  SCIPdebugMsg(scip, "build sub-SCIP for component %d of problem <%s>: %d vars, %d conss\n",
1662  component->number, (*problem)->name, component->nvars, ncompconss);
1663 
1664 #ifndef NDEBUG
1665  {
1666  int i;
1667  for( i = 0; i < component->nvars; ++i )
1668  assert(SCIPvarIsActive(component->vars[i]));
1669  }
1670 #endif
1671 
1672  /* build subscip for component */
1673  SCIP_CALL( componentCreateSubscip(component, conshdlrdata, varmap, consmap, compconss, ncompconss, &success) );
1674 
1675  if( success )
1676  {
1677  SCIP_CALL( componentSetupWorkingSol(component, varmap) );
1678 
1679  /* add component to the priority queue of the problem structure */
1680  SCIP_CALL( SCIPpqueueInsert((*problem)->compqueue, component) );
1681  }
1682 
1683  SCIPhashmapFree(&varmap);
1684 
1685  if( !success )
1686  break;
1687  }
1688 
1689  SCIPhashmapFree(&consmap);
1690 
1691  if( !success )
1692  {
1693  /* free subproblem data structure since not all component could be copied */
1695  }
1696 
1697  return SCIP_OKAY;
1698 }
1699 
1700 /** continue solving a problem */
1701 static
1703  PROBLEM* problem, /**< problem structure */
1704  SCIP_RESULT* result /**< result pointer for the problem solve */
1705  )
1706 {
1707  COMPONENT* component;
1708  SCIP_RESULT subscipresult;
1709 
1710  assert(problem != NULL);
1711 
1712  *result = SCIP_SUCCESS;
1713 
1714  component = (COMPONENT*)SCIPpqueueRemove(problem->compqueue);
1715 
1716  /* continue solving the component */
1717  SCIP_CALL( solveComponent(component, SCIPpqueueNElems(problem->compqueue) == 0, &subscipresult) );
1718 
1719  /* if infeasibility or unboundedness was detected, return this */
1720  if( subscipresult == SCIP_CUTOFF || subscipresult == SCIP_UNBOUNDED )
1721  {
1722  *result = subscipresult;
1723  }
1724  /* the component was not solved to optimality, so we need to re-insert it in the components queue */
1725  else if( !component->solved )
1726  {
1727  SCIP_CALL( SCIPpqueueInsert(problem->compqueue, component) );
1728  *result = SCIP_DELAYNODE;
1729  }
1730  /* no unsolved components are left, so this problem has be completely evaluated and the node can be pruned */
1731  else if( SCIPpqueueNElems(problem->compqueue) == 0 )
1732  *result = SCIP_CUTOFF;
1733  /* there are some unsolved components left, so we delay this node */
1734  else
1735  *result = SCIP_DELAYNODE;
1736 
1737  return SCIP_OKAY;
1738 }
1739 
1740 /*
1741  * Local methods
1742  */
1743 
1744 /** loop over constraints, get active variables and fill directed graph */
1745 static
1747  SCIP* scip, /**< SCIP data structure */
1748  SCIP_DIGRAPH* digraph, /**< directed graph */
1749  SCIP_CONS** conss, /**< constraints */
1750  int nconss, /**< number of constraints */
1751  int* unfixedvarpos, /**< mapping from variable problem index to unfixed var index */
1752  int nunfixedvars, /**< number of unfixed variables */
1753  int* firstvaridxpercons, /**< array to store for each constraint the index in the local vars array
1754  * of the first variable of the constraint */
1755  SCIP_Bool* success /**< flag indicating successful directed graph filling */
1756  )
1757 {
1758  SCIP_VAR** consvars;
1759  int requiredsize;
1760  int nconsvars;
1761  int nvars;
1762  int idx1;
1763  int idx2;
1764  int c;
1765  int v;
1766 
1767  assert(scip != NULL);
1768  assert(digraph != NULL);
1769  assert(conss != NULL);
1770  assert(firstvaridxpercons != NULL);
1771  assert(success != NULL);
1772 
1773  *success = TRUE;
1774 
1775  nconsvars = 0;
1776  requiredsize = 0;
1777  nvars = SCIPgetNVars(scip);
1778 
1779  /* allocate buffer for storing active variables per constraint; size = nvars ensures that it will be big enough */
1780  SCIP_CALL( SCIPallocBufferArray(scip, &consvars, nvars) );
1781 
1782  for( c = 0; c < nconss; ++c )
1783  {
1784  /* check for reached timelimit */
1785  if( (c % 1000 == 0) && SCIPisStopped(scip) )
1786  {
1787  *success = FALSE;
1788  break;
1789  }
1790 
1791  /* get number of variables for this constraint */
1792  SCIP_CALL( SCIPgetConsNVars(scip, conss[c], &nconsvars, success) );
1793 
1794  if( !(*success) )
1795  break;
1796 
1797  /* reallocate consvars array, if needed */
1798  if( nconsvars > nvars )
1799  {
1800  nvars = nconsvars;
1801  SCIP_CALL( SCIPreallocBufferArray(scip, &consvars, nvars) );
1802  }
1803 
1804 #ifndef NDEBUG
1805  /* clearing variables array to check for consistency */
1806  if( nconsvars == nvars )
1807  {
1808  BMSclearMemoryArray(consvars, nconsvars);
1809  }
1810  else
1811  {
1812  assert(nconsvars < nvars);
1813  BMSclearMemoryArray(consvars, nconsvars + 1);
1814  }
1815 #endif
1816 
1817  /* get variables for this constraint */
1818  SCIP_CALL( SCIPgetConsVars(scip, conss[c], consvars, nvars, success) );
1819 
1820  if( !(*success) )
1821  {
1822 #ifndef NDEBUG
1823  /* it looks strange if returning the number of variables was successful but not returning the variables */
1824  SCIPwarningMessage(scip, "constraint <%s> returned number of variables but returning variables failed\n", SCIPconsGetName(conss[c]));
1825 #endif
1826  break;
1827  }
1828 
1829 #ifndef NDEBUG
1830  /* check if returned variables are consistent with the number of variables that were returned */
1831  for( v = nconsvars - 1; v >= 0; --v )
1832  assert(consvars[v] != NULL);
1833  if( nconsvars < nvars )
1834  assert(consvars[nconsvars] == NULL);
1835 #endif
1836 
1837  /* transform given variables to active variables */
1838  SCIP_CALL( SCIPgetActiveVars(scip, consvars, &nconsvars, nvars, &requiredsize) );
1839  assert(requiredsize <= nvars);
1840 
1841  firstvaridxpercons[c] = -1;
1842 
1843  /* store the index of the first unfixed variable and add edges to the directed graph */
1844  if( nconsvars > 0 )
1845  {
1846  v = 0;
1847  idx1 = -1;
1848 
1849  /* go through variables until the first unfixed one is reached (which has unfixedvarpos >= 0) */
1850  while( idx1 == -1 && v < nconsvars )
1851  {
1852  idx1 = SCIPvarGetProbindex(consvars[v]);
1853  assert(idx1 >= 0);
1854  idx1 = unfixedvarpos[idx1];
1855  assert(idx1 < nunfixedvars);
1856  ++v;
1857  }
1858 
1859  if( idx1 >= 0 )
1860  {
1861  /* save index of the first variable for later component assignment */
1862  firstvaridxpercons[c] = idx1;
1863 
1864  /* create sparse directed graph; sparse means to add only those edges necessary for component calculation,
1865  * i.e., add edges from the first variable to all others
1866  */
1867  for(; v < nconsvars; ++v )
1868  {
1869  idx2 = SCIPvarGetProbindex(consvars[v]);
1870  assert(idx2 >= 0);
1871  idx2 = unfixedvarpos[idx2];
1872  assert(idx2 < nunfixedvars);
1873 
1874  /* variable is fixed */
1875  if( idx2 < 0 )
1876  continue;
1877 
1878  /* we add only one directed edge, because the other direction is automatically added for component computation */
1879  SCIP_CALL( SCIPdigraphAddArc(digraph, idx1, idx2, NULL) );
1880  }
1881  }
1882  }
1883  }
1884 
1885  SCIPfreeBufferArray(scip, &consvars);
1886 
1887  return SCIP_OKAY;
1888 }
1889 
1890 /** search for components in the problem */
1891 static
1893  SCIP* scip, /**< SCIP main data structure */
1894  SCIP_CONSHDLRDATA* conshdlrdata, /**< the components constraint handler data */
1895  SCIP_Real* fixedvarsobjsum, /**< objective contribution of all locally fixed variables, or NULL if
1896  * fixed variables should not be disregarded */
1897  SCIP_VAR** sortedvars, /**< array to store variables sorted by components, should have enough size
1898  * for all variables */
1899  SCIP_CONS** sortedconss, /**< array to store (checked) constraints sorted by components, should have
1900  * enough size for all constraints */
1901  int* compstartsvars, /**< start points of components in sortedvars array */
1902  int* compstartsconss, /**< start points of components in sortedconss array */
1903  int* nsortedvars, /**< pointer to store the number of variables belonging to any component */
1904  int* nsortedconss, /**< pointer to store the number of (checked) constraints in components */
1905  int* ncomponents, /**< pointer to store the number of components */
1906  int* ncompsminsize, /**< pointer to store the number of components not exceeding the minimum size */
1907  int* ncompsmaxsize /**< pointer to store the number of components not exceeding the maximum size */
1908 
1909  )
1910 {
1911  SCIP_CONS** tmpconss;
1912  SCIP_VAR** vars;
1913  SCIP_Bool success;
1914  int ntmpconss;
1915  int nvars;
1916  int c;
1917 
1918  assert(scip != NULL);
1919  assert(conshdlrdata != NULL);
1920  assert(sortedvars != NULL);
1921  assert(sortedconss != NULL);
1922  assert(compstartsvars != NULL);
1923  assert(compstartsconss != NULL);
1924  assert(nsortedvars != NULL);
1925  assert(nsortedconss != NULL);
1926  assert(ncomponents != NULL);
1927  assert(ncompsminsize != NULL);
1928  assert(ncompsmaxsize != NULL);
1929 
1930  vars = SCIPgetVars(scip);
1931  nvars = SCIPgetNVars(scip);
1932 
1933  if( fixedvarsobjsum != NULL )
1934  *fixedvarsobjsum = 0.0;
1935 
1936  *ncomponents = 0;
1937  *ncompsminsize = 0;
1938  *ncompsmaxsize = 0;
1939 
1940  /* collect checked constraints for component detection */
1941  ntmpconss = SCIPgetNConss(scip);
1942  tmpconss = SCIPgetConss(scip);
1943  (*nsortedconss) = 0;
1944  for( c = 0; c < ntmpconss; c++ )
1945  {
1946  sortedconss[(*nsortedconss)] = tmpconss[c];
1947  (*nsortedconss)++;
1948  }
1949 
1950  if( nvars > 1 && *nsortedconss > 1 )
1951  {
1952  int* unfixedvarpos;
1953  int* firstvaridxpercons;
1954  int* varlocks;
1955  int nunfixedvars = 0;
1956  int v;
1957 
1958  /* arrays for storing the first variable in each constraint (for later component assignment), the number of
1959  * variable locks, and the positions in the sortedvars array for all unfixed variables
1960  */
1961  SCIP_CALL( SCIPallocBufferArray(scip, &firstvaridxpercons, *nsortedconss) );
1962  SCIP_CALL( SCIPallocBufferArray(scip, &varlocks, nvars) );
1963  SCIP_CALL( SCIPallocBufferArray(scip, &unfixedvarpos, nvars) );
1964 
1965  /* count number of varlocks for each variable (up + down locks) and multiply it by 2;
1966  * that value is used as an estimate of the number of arcs incident to the variable's node in the digraph
1967  * to be safe, we double this value
1968  */
1969  for( v = 0; v < nvars; ++v )
1970  {
1971  /* variable is not fixed or we do not want to disregard fixed variables */
1972  if( (fixedvarsobjsum == NULL) || SCIPisLT(scip, SCIPvarGetLbLocal(vars[v]), SCIPvarGetUbLocal(vars[v])) )
1973  {
1974  assert(nunfixedvars <= v);
1975  sortedvars[nunfixedvars] = vars[v];
1976  varlocks[nunfixedvars] = 4 * (SCIPvarGetNLocksDownType(vars[v], SCIP_LOCKTYPE_MODEL)
1978  unfixedvarpos[v] = nunfixedvars;
1979  ++nunfixedvars;
1980  }
1981  /* variable is fixed; update the objective sum of all fixed variables */
1982  else
1983  {
1984  unfixedvarpos[v] = -1;
1985  (*fixedvarsobjsum) += SCIPvarGetObj(vars[v]) * SCIPvarGetLbLocal(vars[v]);
1986  }
1987  }
1988  *nsortedvars = nunfixedvars;
1989 
1990  if( nunfixedvars > 0 )
1991  {
1992  SCIP_DIGRAPH* digraph;
1993 
1994  /* create and fill directed graph */
1995  SCIP_CALL( SCIPcreateDigraph(scip, &digraph, nunfixedvars) );
1996  SCIP_CALL( SCIPdigraphSetSizes(digraph, varlocks) );
1997  SCIP_CALL( fillDigraph(scip, digraph, sortedconss, *nsortedconss, unfixedvarpos, nunfixedvars, firstvaridxpercons, &success) );
1998 
1999  if( success )
2000  {
2001  int* varcomponent;
2002  int* conscomponent;
2003 
2004  SCIP_CALL( SCIPallocBufferArray(scip, &varcomponent, nunfixedvars) );
2005  SCIP_CALL( SCIPallocBufferArray(scip, &conscomponent, MAX(nunfixedvars,*nsortedconss)) );
2006 
2007  /* compute independent components */
2008  SCIP_CALL( SCIPdigraphComputeUndirectedComponents(digraph, 1, varcomponent, ncomponents) );
2009 
2010  if( *ncomponents > 1 )
2011  {
2012  int nconss = *nsortedconss;
2013  int i;
2014 
2015  nvars = *nsortedvars;
2016 
2018  "cons components found %d undirected components at node %lld, depth %d (%d)\n",
2019  *ncomponents, SCIPnodeGetNumber(SCIPgetCurrentNode(scip)), SCIPgetDepth(scip), SCIPgetDepth(scip) + conshdlrdata->subscipdepth);
2020 
2021  /* sort components by size and sort variables and constraints by component number */
2022  SCIP_CALL( sortComponents(scip, conshdlrdata, digraph, sortedconss, sortedvars, varcomponent, conscomponent, nconss, *nsortedvars,
2023  firstvaridxpercons, ncompsminsize, ncompsmaxsize) );
2024 
2025  /* determine start indices of components in sortedvars and sortedconss array */
2026  i = 0;
2027 
2028  while( i < nconss && conscomponent[i] == -1 )
2029  ++i;
2030 
2031  for( c = 0; c < *ncomponents + 1; ++c )
2032  {
2033  assert(i == nconss || conscomponent[i] >= c);
2034 
2035  compstartsconss[c] = i;
2036 
2037  while( i < nconss && conscomponent[i] == c )
2038  ++i;
2039  }
2040 
2041  for( c = 0, i = 0; c < *ncomponents + 1; ++c )
2042  {
2043  assert(i == nvars || varcomponent[i] >= c);
2044 
2045  compstartsvars[c] = i;
2046 
2047  while( i < nvars && varcomponent[i] == c )
2048  ++i;
2049  }
2050 
2051 #ifndef NDEBUG
2052  for( c = 0; c < *ncomponents; ++c )
2053  {
2054  for( i = compstartsconss[c]; i < compstartsconss[c+1]; ++i )
2055  assert(conscomponent[i] == c);
2056  for( i = compstartsvars[c]; i < compstartsvars[c+1]; ++i )
2057  assert(varcomponent[i] == c);
2058  }
2059 #endif
2060  }
2061 
2062  SCIPfreeBufferArray(scip, &conscomponent);
2063  SCIPfreeBufferArray(scip, &varcomponent);
2064  }
2065 
2066  SCIPdigraphFree(&digraph);
2067  }
2068 
2069  SCIPfreeBufferArray(scip, &unfixedvarpos);
2070  SCIPfreeBufferArray(scip, &varlocks);
2071  SCIPfreeBufferArray(scip, &firstvaridxpercons);
2072  }
2073 
2074  return SCIP_OKAY;
2075 }
2076 
2077 
2078 /*
2079  * Callback methods of constraint handler
2080  */
2081 
2082 /** copy method for constraint handler plugins (called when SCIP copies plugins) */
2083 static
2084 SCIP_DECL_CONSHDLRCOPY(conshdlrCopyComponents)
2085 { /*lint --e{715}*/
2086  assert(scip != NULL);
2087  assert(conshdlr != NULL);
2088  assert(strcmp(SCIPconshdlrGetName(conshdlr), CONSHDLR_NAME) == 0);
2089 
2090  /* call inclusion method of constraint handler */
2092 
2093  *valid = TRUE;
2094 
2095  return SCIP_OKAY;
2096 }
2097 
2098 /** destructor of constraint handler to free user data (called when SCIP is exiting) */
2099 static
2100 SCIP_DECL_CONSFREE(conshdlrFreeComponents)
2101 { /*lint --e{715}*/
2102  SCIP_CONSHDLRDATA* conshdlrdata;
2103 
2104  /* free constraint handler data */
2105  conshdlrdata = SCIPconshdlrGetData(conshdlr);
2106  assert(conshdlrdata != NULL);
2107 
2108  SCIPfreeBlockMemory(scip, &conshdlrdata);
2109  SCIPconshdlrSetData(conshdlr, NULL);
2110 
2111  return SCIP_OKAY;
2112 }
2113 
2114 /** domain propagation method of constraint handler */
2115 static
2116 SCIP_DECL_CONSPROP(consPropComponents)
2117 { /*lint --e{715}*/
2118  PROBLEM* problem;
2119  SCIP_CONSHDLRDATA* conshdlrdata;
2120  SCIP_Longint nodelimit;
2121 
2122  assert(conshdlr != NULL);
2123  assert(strcmp(SCIPconshdlrGetName(conshdlr), CONSHDLR_NAME) == 0);
2124  assert(result != NULL);
2125  assert(SCIPconshdlrGetNActiveConss(conshdlr) >= 0);
2126  assert(SCIPconshdlrGetNActiveConss(conshdlr) <= 1);
2127 
2128  conshdlrdata = SCIPconshdlrGetData(conshdlr);
2129  assert(conshdlrdata != NULL);
2130 
2131  *result = SCIP_DIDNOTRUN;
2132 
2133  /* do not try to detect independent components if the depth is too high */
2134  if( SCIPgetDepth(scip) + conshdlrdata->subscipdepth > conshdlrdata->maxdepth
2135  && SCIPconshdlrGetNActiveConss(conshdlr) == 0 )
2136  return SCIP_OKAY;
2137 
2138  /* don't run in probing or in repropagation */
2139  if( SCIPinProbing(scip) || SCIPinRepropagation(scip) )
2140  return SCIP_OKAY;
2141 
2142  /* do not run, if not all variables are explicitly known */
2143  if( SCIPgetNActivePricers(scip) > 0 )
2144  return SCIP_OKAY;
2145 
2146  /* we do not want to run, if there are no variables left */
2147  if( SCIPgetNVars(scip) == 0 )
2148  return SCIP_OKAY;
2149 
2150  /* check for a reached timelimit */
2151  if( SCIPisStopped(scip) )
2152  return SCIP_OKAY;
2153 
2154  /* the components constraint handler does kind of dual reductions */
2155  if( !SCIPallowStrongDualReds(scip) || !SCIPallowWeakDualReds(scip) )
2156  return SCIP_OKAY;
2157 
2158  problem = NULL;
2159  *result = SCIP_DIDNOTFIND;
2160 
2161  /* the current node already has a components constraint storing a problem split into individual components */
2162  if( SCIPconshdlrGetNActiveConss(conshdlr) >= 1 )
2163  {
2164  assert(SCIPconshdlrGetNActiveConss(conshdlr) == 1);
2165 
2166  problem = (PROBLEM*)SCIPconsGetData(SCIPconshdlrGetConss(conshdlr)[0]);
2167  }
2168  /* no components constraint at the current node, search for components */
2169  else
2170  {
2172  SCIP_VAR** sortedvars;
2173  SCIP_CONS** sortedconss;
2174  int* compstartsvars;
2175  int* compstartsconss;
2176  int nsortedvars;
2177  int nsortedconss;
2178  int ncomponents;
2179  int ncompsminsize;
2180  int ncompsmaxsize;
2181 
2182  assert(SCIPconshdlrGetNActiveConss(conshdlr) == 0);
2183 
2184  /* allocate memory for sorted components */
2185  SCIP_CALL( SCIPallocBufferArray(scip, &sortedvars, SCIPgetNVars(scip)) );
2186  SCIP_CALL( SCIPallocBufferArray(scip, &sortedconss, SCIPgetNConss(scip)) );
2187  SCIP_CALL( SCIPallocBufferArray(scip, &compstartsvars, SCIPgetNVars(scip) + 1) );
2188  SCIP_CALL( SCIPallocBufferArray(scip, &compstartsconss, SCIPgetNVars(scip) + 1) );
2189 
2190  /* search for components */
2191  SCIP_CALL( findComponents(scip, conshdlrdata, &fixedvarsobjsum, sortedvars, sortedconss, compstartsvars,
2192  compstartsconss, &nsortedvars, &nsortedconss, &ncomponents, &ncompsminsize, &ncompsmaxsize) );
2193 
2194  if( ncompsminsize > 1 )
2195  {
2196  SCIP_CONS* cons;
2197 
2198  SCIPdebugMsg(scip, "found %d components (%d fulfulling the minsize requirement) at node %lld at depth %d (%d)\n",
2199  ncomponents, ncompsminsize, SCIPnodeGetNumber(SCIPgetCurrentNode(scip)), SCIPgetDepth(scip),
2200  SCIPgetDepth(scip) + conshdlrdata->subscipdepth);
2201 
2202  /* if there are components with size smaller than the limit, we merge them with the smallest component */
2203  if( ncomponents > ncompsminsize )
2204  {
2205  int minsize;
2206  int size;
2207  int c;
2208  int m = 0;
2209 
2210  /* compute minimum size of components to solve individually */
2211  minsize = getMinsize(scip, conshdlrdata);
2212 
2213  for( c = 0; c < ncomponents; ++c )
2214  {
2215  size = compstartsvars[c+1] - compstartsvars[c];
2216 
2217  if( size >= minsize )
2218  {
2219  ++m;
2220  compstartsvars[m] = compstartsvars[c+1];
2221  compstartsconss[m] = compstartsconss[c+1];
2222  }
2223  /* the last component is too small */
2224  else if( c == ncomponents - 1 )
2225  {
2226  assert(m == ncompsminsize);
2227  compstartsvars[m] = compstartsvars[c+1];
2228  compstartsconss[m] = compstartsconss[c+1];
2229  }
2230  }
2231  assert(m == ncompsminsize);
2232  assert(compstartsvars[m] == nsortedvars);
2233  assert(compstartsconss[m] == nsortedconss);
2234 
2235  ncomponents = m;
2236  }
2237 
2238  SCIP_CALL( createAndSplitProblem(scip, conshdlrdata, fixedvarsobjsum, sortedvars, sortedconss, compstartsvars,
2239  compstartsconss, ncomponents, &problem) );
2240 
2241  /* if the problem is not NULL, copying worked fine */
2242  if( problem != NULL )
2243  {
2244  SCIP_CALL( createConsComponents(scip, &cons, problem->name, problem) );
2245  SCIP_CALL( SCIPaddConsNode(scip, SCIPgetCurrentNode(scip), cons, NULL) );
2246  SCIP_CALL( SCIPreleaseCons(scip, &cons) );
2247  }
2248  }
2249 
2250  SCIPfreeBufferArray(scip, &compstartsconss);
2251  SCIPfreeBufferArray(scip, &compstartsvars);
2252  SCIPfreeBufferArray(scip, &sortedconss);
2253  SCIPfreeBufferArray(scip, &sortedvars);
2254  }
2255 
2256  /* (continue to) solve the problem
2257  *
2258  * If the problem was not solved to optimality yet, the result code is set to SCIP_DELAYNODE, so that after the
2259  * propagation is finished, the node is put back into the queue of open nodes and solving the components of the
2260  * problem will be continued when the node is focused and propagated the next time.
2261  * However, if we are at the root node, we continue solving the problem until it is solved or some limit is reached
2262  * since there are no other nodes to process and we want to avoid calling other propagation methods or heuristics
2263  * again and again
2264  */
2265  SCIP_CALL( SCIPgetLongintParam(scip, "limits/nodes", &nodelimit) );
2266  if( nodelimit == -1 )
2267  nodelimit = SCIP_LONGINT_MAX;
2268 
2269  do
2270  {
2271  if( problem != NULL )
2272  {
2273  SCIP_CALL( solveProblem(problem, result) );
2274  }
2275  } while( *result == SCIP_DELAYNODE && SCIPgetDepth(scip) == 0 && !SCIPisStopped(scip) && SCIPgetNNodes(scip) < nodelimit);
2276 
2277  return SCIP_OKAY;
2278 }
2279 
2280 /** presolving method of constraint handler */
2281 static
2282 SCIP_DECL_CONSPRESOL(consPresolComponents)
2283 { /*lint --e{715}*/
2284  SCIP_CONSHDLRDATA* conshdlrdata;
2285  SCIP_VAR** sortedvars;
2286  SCIP_CONS** sortedconss;
2287  int* compstartsvars;
2288  int* compstartsconss;
2289  int nsortedvars;
2290  int nsortedconss;
2291  int ncomponents;
2292  int ncompsminsize;
2293  int ncompsmaxsize;
2294  int nvars;
2295 
2296  assert(conshdlr != NULL);
2297  assert(strcmp(SCIPconshdlrGetName(conshdlr), CONSHDLR_NAME) == 0);
2298  assert(result != NULL);
2299  assert(SCIPconshdlrGetNActiveConss(conshdlr) >= 0);
2300  assert(SCIPconshdlrGetNActiveConss(conshdlr) <= 1);
2301 
2302  conshdlrdata = SCIPconshdlrGetData(conshdlr);
2303  assert(conshdlrdata != NULL);
2304 
2305  *result = SCIP_DIDNOTRUN;
2306 
2307  if( SCIPgetStage(scip) != SCIP_STAGE_PRESOLVING || SCIPinProbing(scip) )
2308  return SCIP_OKAY;
2309 
2310  /* do not run, if not all variables are explicitly known */
2311  if( SCIPgetNActivePricers(scip) > 0 )
2312  return SCIP_OKAY;
2313 
2314  nvars = SCIPgetNVars(scip);
2315 
2316  /* we do not want to run, if there are no variables left */
2317  if( nvars == 0 )
2318  return SCIP_OKAY;
2319 
2320  /* only call the components presolving, if presolving would be stopped otherwise */
2321  if( !SCIPisPresolveFinished(scip) )
2322  return SCIP_OKAY;
2323 
2324  /* the components constraint handler does kind of dual reductions */
2325  if( !SCIPallowStrongDualReds(scip) || !SCIPallowWeakDualReds(scip) )
2326  return SCIP_OKAY;
2327 
2328  /* check for a reached timelimit */
2329  if( SCIPisStopped(scip) )
2330  return SCIP_OKAY;
2331 
2332  *result = SCIP_DIDNOTFIND;
2333 
2334  assert(SCIPconshdlrGetNActiveConss(conshdlr) == 0);
2335 
2336  /* allocate memory for sorted components */
2337  SCIP_CALL( SCIPallocBufferArray(scip, &sortedvars, SCIPgetNVars(scip)) );
2338  SCIP_CALL( SCIPallocBufferArray(scip, &sortedconss, SCIPgetNConss(scip)) );
2339  SCIP_CALL( SCIPallocBufferArray(scip, &compstartsvars, SCIPgetNVars(scip) + 1) );
2340  SCIP_CALL( SCIPallocBufferArray(scip, &compstartsconss, SCIPgetNVars(scip) + 1) );
2341 
2342  /* search for components */
2343  SCIP_CALL( findComponents(scip, conshdlrdata, NULL, sortedvars, sortedconss, compstartsvars,
2344  compstartsconss, &nsortedvars, &nsortedconss, &ncomponents, &ncompsminsize, &ncompsmaxsize) );
2345 
2346  if( ncompsmaxsize > 0 )
2347  {
2348  char name[SCIP_MAXSTRLEN];
2349  SCIP* subscip;
2350  SCIP_HASHMAP* consmap;
2351  SCIP_HASHMAP* varmap;
2352  SCIP_VAR** compvars;
2353  SCIP_VAR** subvars;
2354  SCIP_CONS** compconss;
2355  SCIP_Bool success;
2356  SCIP_Bool solved;
2357  int nsolved = 0;
2358  int ncompvars;
2359  int ncompconss;
2360  int comp;
2361 
2362  SCIPdebugMsg(scip, "found %d components (%d with small size) during presolving; overall problem size: %d vars (%d int, %d bin, %d cont), %d conss\n",
2363  ncomponents, ncompsmaxsize, SCIPgetNVars(scip), SCIPgetNBinVars(scip), SCIPgetNIntVars(scip), SCIPgetNContVars(scip) + SCIPgetNImplVars(scip), SCIPgetNConss(scip));
2364 
2365  /* build subscip */
2366  SCIP_CALL( createSubscip(scip, conshdlrdata, &subscip) );
2367 
2368  if( subscip == NULL )
2369  goto TERMINATE;
2370 
2371  SCIP_CALL( SCIPsetBoolParam(subscip, "misc/usesmalltables", TRUE) );
2372  SCIP_CALL( SCIPsetIntParam(subscip, "constraints/" CONSHDLR_NAME "/propfreq", -1) );
2373 
2374  /* hashmap mapping from original constraints to constraints in the sub-SCIPs (for performance reasons) */
2375  SCIP_CALL( SCIPhashmapCreate(&consmap, SCIPblkmem(scip), nsortedconss) );
2376 
2377  SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nsortedvars) );
2378 
2379  /* loop over all components */
2380  for( comp = 0; comp < ncompsmaxsize && !SCIPisStopped(scip); comp++ )
2381  {
2382 #ifdef WITH_DEBUG_SOLUTION
2383  if( SCIPgetStage(subscip) > SCIP_STAGE_INIT )
2384  {
2385  SCIP_CALL( SCIPfree(&subscip) );
2386  SCIP_CALL( createSubscip(scip, conshdlrdata, &subscip) );
2387  }
2388 #endif
2389  /* get component variables */
2390  compvars = &(sortedvars[compstartsvars[comp]]);
2391  ncompvars = compstartsvars[comp + 1 ] - compstartsvars[comp];
2392 
2393  /* get component constraints */
2394  compconss = &(sortedconss[compstartsconss[comp]]);
2395  ncompconss = compstartsconss[comp + 1] - compstartsconss[comp];
2396 
2397  /* if we have an unlocked variable, let duality fixing do the job! */
2398  if( ncompconss == 0 )
2399  {
2400  assert(ncompvars == 1);
2401  continue;
2402  }
2403 
2404  SCIP_CALL( SCIPhashmapCreate(&varmap, SCIPblkmem(scip), ncompvars) );
2405 #ifdef DETAILED_OUTPUT
2406  {
2407  int nbinvars = 0;
2408  int nintvars = 0;
2409  int ncontvars = 0;
2410  int i;
2411 
2412  for( i = 0; i < ncompvars; ++i )
2413  {
2414  if( SCIPvarGetType(compvars[i]) == SCIP_VARTYPE_BINARY )
2415  ++nbinvars;
2416  else if( SCIPvarGetType(compvars[i]) == SCIP_VARTYPE_INTEGER )
2417  ++nintvars;
2418  else
2419  ++ncontvars;
2420  }
2421  SCIPdebugMsg(scip, "solve component %d: %d vars (%d bin, %d int, %d cont), %d conss\n",
2422  comp, ncompvars, nbinvars, nintvars, ncontvars, ncompconss);
2423  }
2424 #endif
2425 #ifndef NDEBUG
2426  {
2427  int i;
2428  for( i = 0; i < ncompvars; ++i )
2429  assert(SCIPvarIsActive(compvars[i]));
2430  }
2431 #endif
2432 
2433  /* get name of the original problem and add "comp_nr" */
2434  (void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "%s_comp_%d", SCIPgetProbName(scip), comp);
2435 
2436  SCIP_CALL( copyToSubscip(scip, subscip, name, compvars, subvars,
2437  compconss, varmap, consmap, ncompvars, ncompconss, &success) );
2438 
2439  if( !success )
2440  {
2441  SCIPhashmapFree(&varmap);
2442  continue;
2443  }
2444 
2445  /* set up debug solution */
2446 #ifdef WITH_DEBUG_SOLUTION
2447  if( SCIPdebugSolIsEnabled(scip) )
2448  {
2449  SCIP_SOL* debugsol;
2450  SCIP_Real val;
2451  int i;
2452 
2453  SCIP_CALL( SCIPdebugGetSol(scip, &debugsol) );
2454 
2455  /* set solution values in the debug solution if it is available */
2456  if( debugsol != NULL )
2457  {
2458  SCIPdebugSolEnable(subscip);
2459 
2460  for( i = 0; i < ncompvars; ++i )
2461  {
2462  if( subvars[i] != NULL )
2463  {
2464  SCIP_CALL( SCIPdebugGetSolVal(scip, compvars[i], &val) );
2465  SCIP_CALL( SCIPdebugAddSolVal(subscip, subvars[i], val) );
2466  }
2467  }
2468  }
2469  }
2470 #endif
2471 
2472  /* solve the subproblem and evaluate the result, i.e. apply fixings of variables and remove constraints */
2473  SCIP_CALL( solveAndEvalSubscip(scip, conshdlrdata, subscip, compvars, subvars, compconss,
2474  ncompvars, ncompconss, ndelconss, nfixedvars, nchgbds, result, &solved) );
2475 
2476  /* free variable hash map */
2477  SCIPhashmapFree(&varmap);
2478 
2479  if( solved )
2480  ++nsolved;
2481 
2482  /* if the component is unbounded or infeasible, this holds for the complete problem as well */
2483  if( *result == SCIP_UNBOUNDED || *result == SCIP_CUTOFF )
2484  break;
2485  /* if there is only one component left, let's solve this in the main SCIP */
2486  else if( nsolved == ncomponents - 1 )
2487  break;
2488  }
2489 
2490  SCIPfreeBufferArray(scip, &subvars);
2491  SCIPhashmapFree(&consmap);
2492 
2493  SCIP_CALL( SCIPfree(&subscip) );
2494  }
2495 
2496  TERMINATE:
2497  SCIPfreeBufferArray(scip, &compstartsconss);
2498  SCIPfreeBufferArray(scip, &compstartsvars);
2499  SCIPfreeBufferArray(scip, &sortedconss);
2500  SCIPfreeBufferArray(scip, &sortedvars);
2501 
2502  return SCIP_OKAY;
2503 }
2504 
2505 /** frees specific constraint data */
2506 static
2507 SCIP_DECL_CONSDELETE(consDeleteComponents)
2508 { /*lint --e{715}*/
2509  assert(conshdlr != NULL);
2510  assert(strcmp(SCIPconshdlrGetName(conshdlr), CONSHDLR_NAME) == 0);
2511  assert(consdata != NULL);
2512  assert(*consdata != NULL);
2513 
2514  SCIP_CALL( freeProblem((PROBLEM**) consdata) );
2515 
2516  return SCIP_OKAY;
2517 }
2518 
2519 /** constraint enforcing method of constraint handler for relaxation solutions */
2520 static
2521 SCIP_DECL_CONSENFORELAX(consEnforelaxComponents)
2522 { /*lint --e{715}*/
2523  assert(result != NULL );
2524 
2525  /* no enforcement is performed, but the callback is needed for all constraint handlers with needscons = FALSE */
2526  *result = SCIP_FEASIBLE;
2527 
2528  return SCIP_OKAY;
2529 }
2530 
2531 /** variable rounding lock method of constraint handler */
2532 static
2533 SCIP_DECL_CONSLOCK(consLockComponents)
2534 { /*lint --e{715}*/
2535  return SCIP_OKAY;
2536 }
2537 
2538 #ifndef NDEBUG
2539 /** solving process initialization method of constraint handler (called when branch and bound process is about to begin) */
2540 static
2541 SCIP_DECL_CONSINITSOL(consInitsolComponents)
2542 { /*lint --e{715}*/
2543  assert(nconss == 0);
2544 
2545  return SCIP_OKAY;
2546 }
2547 #endif
2548 
2549 #define consEnfolpComponents NULL
2550 #define consEnfopsComponents NULL
2551 #define consCheckComponents NULL
2553 /** creates the components constraint handler and includes it in SCIP */
2555  SCIP* scip /**< SCIP data structure */
2556  )
2557 {
2558  SCIP_CONSHDLRDATA* conshdlrdata;
2559  SCIP_CONSHDLR* conshdlr;
2560 
2561  /* create components propagator data */
2562  SCIP_CALL( SCIPallocBlockMemory(scip, &conshdlrdata) );
2563  conshdlrdata->subscipdepth = 0;
2564 
2565  /* include constraint handler */
2569  conshdlrdata) );
2570  assert(conshdlr != NULL);
2571 
2572  SCIP_CALL( SCIPsetConshdlrProp(scip, conshdlr, consPropComponents,
2574  SCIP_CALL( SCIPsetConshdlrPresol(scip, conshdlr, consPresolComponents,
2576 
2577  SCIP_CALL( SCIPsetConshdlrFree(scip, conshdlr, conshdlrFreeComponents) );
2578  SCIP_CALL( SCIPsetConshdlrEnforelax(scip, conshdlr, consEnforelaxComponents) );
2579 #ifndef NDEBUG
2580  SCIP_CALL( SCIPsetConshdlrInitsol(scip, conshdlr, consInitsolComponents) );
2581 #endif
2582  SCIP_CALL( SCIPsetConshdlrCopy(scip, conshdlr, conshdlrCopyComponents, NULL) );
2583  SCIP_CALL( SCIPsetConshdlrDelete(scip, conshdlr, consDeleteComponents) );
2584 
2585  SCIP_CALL( SCIPaddIntParam(scip,
2586  "constraints/" CONSHDLR_NAME "/maxdepth",
2587  "maximum depth of a node to run components detection (-1: disable component detection during solving)",
2588  &conshdlrdata->maxdepth, FALSE, DEFAULT_MAXDEPTH, -1, INT_MAX, NULL, NULL) );
2589  SCIP_CALL( SCIPaddIntParam(scip,
2590  "constraints/" CONSHDLR_NAME "/maxintvars",
2591  "maximum number of integer (or binary) variables to solve a subproblem during presolving (-1: unlimited)",
2592  &conshdlrdata->maxintvars, TRUE, DEFAULT_MAXINTVARS, -1, INT_MAX, NULL, NULL) );
2593  SCIP_CALL( SCIPaddIntParam(scip,
2594  "constraints/" CONSHDLR_NAME "/minsize",
2595  "minimum absolute size (in terms of variables) to solve a component individually during branch-and-bound",
2596  &conshdlrdata->minsize, TRUE, DEFAULT_MINSIZE, 0, INT_MAX, NULL, NULL) );
2598  "constraints/" CONSHDLR_NAME "/minrelsize",
2599  "minimum relative size (in terms of variables) to solve a component individually during branch-and-bound",
2600  &conshdlrdata->minrelsize, TRUE, DEFAULT_MINRELSIZE, 0.0, 1.0, NULL, NULL) );
2602  "constraints/" CONSHDLR_NAME "/nodelimit",
2603  "maximum number of nodes to be solved in subproblems during presolving",
2604  &conshdlrdata->nodelimit, FALSE, DEFAULT_NODELIMIT, -1LL, SCIP_LONGINT_MAX, NULL, NULL) );
2606  "constraints/" CONSHDLR_NAME "/intfactor",
2607  "the weight of an integer variable compared to binary variables",
2608  &conshdlrdata->intfactor, FALSE, DEFAULT_INTFACTOR, 0.0, SCIP_REAL_MAX, NULL, NULL) );
2610  "constraints/" CONSHDLR_NAME "/feastolfactor",
2611  "factor to increase the feasibility tolerance of the main SCIP in all sub-SCIPs, default value 1.0",
2612  &conshdlrdata->feastolfactor, TRUE, DEFAULT_FEASTOLFACTOR, 0.0, 1000000.0, NULL, NULL) );
2613 
2614  return SCIP_OKAY;
2615 }
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
void SCIPsortRealInt(SCIP_Real *realarray, int *intarray, int len)
SCIP_RETCODE SCIPprintBestSol(SCIP *scip, FILE *file, SCIP_Bool printzeros)
Definition: scip_sol.c:2379
#define SCIPfreeBlockMemoryArray(scip, ptr, num)
Definition: scip_mem.h:110
int SCIPgetNIntVars(SCIP *scip)
Definition: scip_prob.c:2090
void SCIPconshdlrSetData(SCIP_CONSHDLR *conshdlr, SCIP_CONSHDLRDATA *conshdlrdata)
Definition: cons.c:4212
#define CONSHDLR_ENFOPRIORITY
int SCIPpqueueNElems(SCIP_PQUEUE *pqueue)
Definition: misc.c:1477
SCIP_RETCODE SCIPsetConshdlrDelete(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSDELETE((*consdelete)))
Definition: scip_cons.c:572
SCIP_Bool SCIPinRepropagation(SCIP *scip)
Definition: scip_tree.c:146
SCIP_Real SCIPgetSolvingTime(SCIP *scip)
Definition: scip_timing.c:378
#define DEFAULT_MAXINTVARS
#define SCIPallocBlockMemoryArray(scip, ptr, num)
Definition: scip_mem.h:93
SCIP_RETCODE SCIPtightenVarLb(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:5203
SCIP_Bool SCIPisFeasEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public methods for SCIP parameter handling
int SCIPvarGetNLocksDownType(SCIP_VAR *var, SCIP_LOCKTYPE locktype)
Definition: var.c:3299
SCIP_NODE * SCIPgetCurrentNode(SCIP *scip)
Definition: scip_tree.c:91
SCIP_STAGE SCIPgetStage(SCIP *scip)
Definition: scip_general.c:365
SCIP_Bool SCIPconsIsDynamic(SCIP_CONS *cons)
Definition: cons.c:8349
public methods for branch and bound tree
#define SCIPduplicateMemoryArray(scip, ptr, source, num)
Definition: scip_mem.h:76
SCIP_Bool SCIPisFeasLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
static SCIP_RETCODE freeProblem(PROBLEM **problem)
public methods for memory management
SCIP_CONSHDLR * SCIPfindConshdlr(SCIP *scip, const char *name)
Definition: scip_cons.c:886
SCIP_Real SCIPgetCutoffbound(SCIP *scip)
SCIP_Real SCIPgetPrimalbound(SCIP *scip)
#define SCIPfreeMemoryArray(scip, ptr)
Definition: scip_mem.h:80
SCIP_Real SCIPvarGetLbGlobal(SCIP_VAR *var)
Definition: var.c:17923
static SCIP_DECL_CONSENFORELAX(consEnforelaxComponents)
SCIP_RETCODE SCIPgetRealParam(SCIP *scip, const char *name, SCIP_Real *value)
Definition: scip_param.c:307
SCIP_RETCODE SCIPupdateCutoffbound(SCIP *scip, SCIP_Real cutoffbound)
#define SCIP_MAXSTRLEN
Definition: def.h:302
int SCIPvarGetNLocksUpType(SCIP_VAR *var, SCIP_LOCKTYPE locktype)
Definition: var.c:3357
SCIP_RETCODE SCIPsetConshdlrEnforelax(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSENFORELAX((*consenforelax)))
Definition: scip_cons.c:317
SCIP_RETCODE SCIPdigraphComputeUndirectedComponents(SCIP_DIGRAPH *digraph, int minsize, int *components, int *ncomponents)
Definition: misc.c:8001
SCIP_RETCODE SCIPdelCons(SCIP *scip, SCIP_CONS *cons)
Definition: scip_prob.c:2851
SCIP_Bool SCIPisPositive(SCIP *scip, SCIP_Real val)
int SCIPgetNOrigVars(SCIP *scip)
Definition: scip_prob.c:2440
SCIP_Real SCIPvarGetLbLocal(SCIP_VAR *var)
Definition: var.c:17979
static SCIP_DECL_CONSDELETE(consDeleteComponents)
SCIP_Bool SCIPisGE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public solving methods
public methods for timing
#define DEFAULT_INTFACTOR
SCIP_Bool SCIPisFeasGE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
SCIP_RETCODE SCIPprintDisplayLine(SCIP *scip, FILE *file, SCIP_VERBLEVEL verblevel, SCIP_Bool endline)
SCIP_CONS ** SCIPconshdlrGetConss(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4554
#define FALSE
Definition: def.h:96
SCIP_RETCODE SCIPhashmapCreate(SCIP_HASHMAP **hashmap, BMS_BLKMEM *blkmem, int mapsize)
Definition: misc.c:3024
static SCIP_RETCODE solveSubscip(SCIP *scip, SCIP *subscip, SCIP_Longint nodelimit, SCIP_Real gaplimit)
#define CONSHDLR_EAGERFREQ
SCIP_RETCODE SCIPaddLongintParam(SCIP *scip, const char *name, const char *desc, SCIP_Longint *valueptr, SCIP_Bool isadvanced, SCIP_Longint defaultvalue, SCIP_Longint minvalue, SCIP_Longint maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:111
SCIP_RETCODE SCIPcopyLimits(SCIP *sourcescip, SCIP *targetscip)
Definition: scip_copy.c:3287
SCIP_RETCODE SCIPincludeConshdlrBasic(SCIP *scip, SCIP_CONSHDLR **conshdlrptr, const char *name, const char *desc, int enfopriority, int chckpriority, int eagerfreq, SCIP_Bool needscons, SCIP_DECL_CONSENFOLP((*consenfolp)), SCIP_DECL_CONSENFOPS((*consenfops)), SCIP_DECL_CONSCHECK((*conscheck)), SCIP_DECL_CONSLOCK((*conslock)), SCIP_CONSHDLRDATA *conshdlrdata)
Definition: scip_cons.c:175
int SCIPgetNActivePricers(SCIP *scip)
Definition: scip_pricer.c:348
SCIP_Real SCIPinfinity(SCIP *scip)
int SCIPsnprintf(char *t, int len, const char *s,...)
Definition: misc.c:10788
static int getMinsize(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata)
SCIP_Bool SCIPisNegative(SCIP *scip, SCIP_Real val)
#define TRUE
Definition: def.h:95
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_RETCODE SCIPdigraphSetSizes(SCIP_DIGRAPH *digraph, int *sizes)
Definition: misc.c:7456
SCIP_RETCODE SCIPsetPresolving(SCIP *scip, SCIP_PARAMSETTING paramsetting, SCIP_Bool quiet)
Definition: scip_param.c:932
int SCIPvarGetProbindex(SCIP_VAR *var)
Definition: var.c:17613
SCIP_RETCODE SCIPincludeConshdlrComponents(SCIP *scip)
public methods for problem variables
PROBLEM * problem
SCIP_RETCODE SCIPtightenVarUb(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:5320
int SCIPdigraphGetNComponents(SCIP_DIGRAPH *digraph)
Definition: misc.c:8196
#define SCIPfreeBlockMemory(scip, ptr)
Definition: scip_mem.h:108
void SCIPpqueueFree(SCIP_PQUEUE **pqueue)
Definition: misc.c:1272
#define SCIPdebugMessage
Definition: pub_message.h:96
void SCIPdigraphGetComponent(SCIP_DIGRAPH *digraph, int compidx, int **nodes, int *nnodes)
Definition: misc.c:8209
SCIP_Real lastprimalbound
SCIP_CONS ** SCIPgetConss(SCIP *scip)
Definition: scip_prob.c:3096
void * SCIPhashmapGetImage(SCIP_HASHMAP *hashmap, void *origin)
Definition: misc.c:3211
SCIP_Bool SCIPisEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define DEFAULT_MAXDEPTH
#define SCIP_LONGINT_MAX
Definition: def.h:172
#define SCIPfreeBufferArray(scip, ptr)
Definition: scip_mem.h:136
SCIP_RETCODE SCIPcreate(SCIP **scip)
Definition: scip_general.c:292
constraint handler for handling independent components
#define SCIPallocBlockMemory(scip, ptr)
Definition: scip_mem.h:89
static SCIP_RETCODE freeComponent(COMPONENT *component)
public methods for SCIP variables
SCIP_RETCODE SCIPsetRealParam(SCIP *scip, const char *name, SCIP_Real value)
Definition: scip_param.c:603
SCIP_Bool SCIPconsIsRemovable(SCIP_CONS *cons)
Definition: cons.c:8359
SCIP_RETCODE SCIPcopyPlugins(SCIP *sourcescip, SCIP *targetscip, SCIP_Bool copyreaders, SCIP_Bool copypricers, SCIP_Bool copyconshdlrs, SCIP_Bool copyconflicthdlrs, SCIP_Bool copypresolvers, SCIP_Bool copyrelaxators, SCIP_Bool copyseparators, SCIP_Bool copycutselectors, SCIP_Bool copypropagators, SCIP_Bool copyheuristics, SCIP_Bool copyeventhdlrs, SCIP_Bool copynodeselectors, SCIP_Bool copybranchrules, SCIP_Bool copydisplays, SCIP_Bool copydialogs, SCIP_Bool copytables, SCIP_Bool copyexprhdlrs, SCIP_Bool copynlpis, SCIP_Bool passmessagehdlr, SCIP_Bool *valid)
Definition: scip_copy.c:275
void SCIPwarningMessage(SCIP *scip, const char *formatstr,...)
Definition: scip_message.c:120
#define SCIPdebugMsg
Definition: scip_message.h:78
SCIP_RETCODE SCIPaddIntParam(SCIP *scip, const char *name, const char *desc, int *valueptr, SCIP_Bool isadvanced, int defaultvalue, int minvalue, int maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:83
SCIP_RETCODE SCIPcopyParamSettings(SCIP *sourcescip, SCIP *targetscip)
Definition: scip_copy.c:2559
static SCIP_RETCODE solveAndEvalSubscip(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata, SCIP *subscip, SCIP_VAR **vars, SCIP_VAR **subvars, SCIP_CONS **conss, int nvars, int nconss, int *ndeletedconss, int *nfixedvars, int *ntightenedbounds, SCIP_RESULT *result, SCIP_Bool *solved)
SCIP_RETCODE SCIPprintStatistics(SCIP *scip, FILE *file)
int SCIPgetNContVars(SCIP *scip)
Definition: scip_prob.c:2180
SCIP_RETCODE SCIPcreateCons(SCIP *scip, SCIP_CONS **cons, const char *name, SCIP_CONSHDLR *conshdlr, SCIP_CONSDATA *consdata, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode)
Definition: scip_cons.c:943
SCIP_RETCODE SCIPcreateDigraph(SCIP *scip, SCIP_DIGRAPH **digraph, int nnodes)
SCIP_RETCODE SCIPcreateOrigSol(SCIP *scip, SCIP_SOL **sol, SCIP_HEUR *heur)
Definition: scip_sol.c:565
SCIP_Real SCIPsolGetOrigObj(SCIP_SOL *sol)
Definition: sol.c:2550
#define consEnfopsComponents
public methods for numerical tolerances
public methods for querying solving statistics
const char * SCIPgetProbName(SCIP *scip)
Definition: scip_prob.c:1075
void SCIPsortIntPtr(int *intarray, void **ptrarray, int len)
public methods for the branch-and-bound tree
static SCIP_DECL_CONSLOCK(consLockComponents)
SCIP_Longint SCIPnodeGetNumber(SCIP_NODE *node)
Definition: tree.c:7436
SCIP_Bool solved
SCIP_Real SCIPvarGetUbGlobal(SCIP_VAR *var)
Definition: var.c:17933
SCIP_RETCODE SCIPsetConshdlrInitsol(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSINITSOL((*consinitsol)))
Definition: scip_cons.c:438
#define SCIPduplicateBlockMemoryArray(scip, ptr, source, num)
Definition: scip_mem.h:105
#define CONSHDLR_CHECKPRIORITY
#define CONSHDLR_NAME
static SCIP_RETCODE copyToSubscip(SCIP *scip, SCIP *subscip, const char *name, SCIP_VAR **vars, SCIP_VAR **subvars, SCIP_CONS **conss, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, int nvars, int nconss, SCIP_Bool *success)
public methods for managing constraints
SCIP_VAR ** subvars
SCIP_Bool SCIPisPresolveFinished(SCIP *scip)
Definition: scip_general.c:612
SCIP_Real lastdualbound
SCIP_RETCODE SCIPsolve(SCIP *scip)
Definition: scip_solve.c:2624
SCIP_RETCODE SCIPsetConshdlrCopy(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSHDLRCOPY((*conshdlrcopy)), SCIP_DECL_CONSCOPY((*conscopy)))
Definition: scip_cons.c:341
const char * SCIPheurGetName(SCIP_HEUR *heur)
Definition: heur.c:1450
SCIP_HEUR * SCIPfindHeur(SCIP *scip, const char *name)
Definition: scip_heur.c:258
#define CONSHDLR_PRESOLTIMING
#define SCIPerrorMessage
Definition: pub_message.h:64
const char * SCIPconshdlrGetName(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4182
SCIP_Bool SCIPisParamFixed(SCIP *scip, const char *name)
Definition: scip_param.c:219
SCIP_RETCODE SCIPgetConsNVars(SCIP *scip, SCIP_CONS *cons, int *nvars, SCIP_Bool *success)
Definition: scip_cons.c:2567
SCIP_RETCODE SCIPaddCons(SCIP *scip, SCIP_CONS *cons)
Definition: scip_prob.c:2778
SCIP_Bool SCIPisLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
static SCIP_DECL_CONSHDLRCOPY(conshdlrCopyComponents)
SCIP_Real SCIPgetDualbound(SCIP *scip)
SCIP_RETCODE SCIPsetBoolParam(SCIP *scip, const char *name, SCIP_Bool value)
Definition: scip_param.c:429
SCIP_STATUS SCIPgetStatus(SCIP *scip)
Definition: scip_general.c:483
BMS_BLKMEM * SCIPblkmem(SCIP *scip)
Definition: scip_mem.c:57
const char * SCIPconsGetName(SCIP_CONS *cons)
Definition: cons.c:8090
SCIP_RETCODE SCIPcheckSolOrig(SCIP *scip, SCIP_SOL *sol, SCIP_Bool *feasible, SCIP_Bool printreason, SCIP_Bool completely)
Definition: scip_sol.c:3507
SCIP_Bool SCIPconsIsPropagated(SCIP_CONS *cons)
Definition: cons.c:8309
#define CONSHDLR_MAXPREROUNDS
const char * SCIPvarGetName(SCIP_VAR *var)
Definition: var.c:17264
SCIP_STATUS laststatus
SCIP_RETCODE SCIPsetConshdlrFree(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSFREE((*consfree)))
Definition: scip_cons.c:366
void SCIPhashmapFree(SCIP_HASHMAP **hashmap)
Definition: misc.c:3058
SCIP_CONSHDLRDATA * SCIPconshdlrGetData(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4202
SCIP_RETCODE SCIPgetBoolParam(SCIP *scip, const char *name, SCIP_Bool *value)
Definition: scip_param.c:250
#define NULL
Definition: lpi_spx1.cpp:164
SCIP_HEUR * SCIPsolGetHeur(SCIP_SOL *sol)
Definition: sol.c:2613
SCIP_Real SCIPgetSolTransObj(SCIP *scip, SCIP_SOL *sol)
Definition: scip_sol.c:1491
SCIP_PARAM * SCIPgetParam(SCIP *scip, const char *name)
Definition: scip_param.c:234
public methods for problem copies
public methods for primal CIP solutions
#define CONSHDLR_DELAYPROP
static SCIP_RETCODE componentSetupWorkingSol(COMPONENT *component, SCIP_HASHMAP *varmap)
#define SCIP_CALL(x)
Definition: def.h:394
SCIP_Bool SCIPisFeasGT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
struct Component COMPONENT
SCIP_Bool SCIPisFeasLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
static SCIP_DECL_SORTPTRCOMP(componentSort)
void SCIPverbMessage(SCIP *scip, SCIP_VERBLEVEL msgverblevel, FILE *file, const char *formatstr,...)
Definition: scip_message.c:225
SCIP_RETCODE SCIPdigraphAddArc(SCIP_DIGRAPH *digraph, int startnode, int endnode, void *data)
Definition: misc.c:7574
#define SCIPdebugGetSolVal(scip, var, val)
Definition: debug.h:299
SCIP_RETCODE SCIPgetLongintParam(SCIP *scip, const char *name, SCIP_Longint *value)
Definition: scip_param.c:288
struct SCIP_ConsData SCIP_CONSDATA
Definition: type_cons.h:65
void * SCIPpqueueRemove(SCIP_PQUEUE *pqueue)
Definition: misc.c:1443
SCIP_RETCODE SCIPgetConsVars(SCIP *scip, SCIP_CONS *cons, SCIP_VAR **vars, int varssize, SCIP_Bool *success)
Definition: scip_cons.c:2523
public methods for primal heuristic plugins and divesets
public methods for constraint handler plugins and constraints
SCIP_RETCODE SCIPgetConsCopy(SCIP *sourcescip, SCIP *targetscip, SCIP_CONS *sourcecons, SCIP_CONS **targetcons, SCIP_CONSHDLR *sourceconshdlr, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, const char *name, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode, SCIP_Bool global, SCIP_Bool *valid)
Definition: scip_copy.c:1586
SCIP_RETCODE SCIPaddConsNode(SCIP *scip, SCIP_NODE *node, SCIP_CONS *cons, SCIP_NODE *validnode)
Definition: scip_prob.c:3331
static SCIP_DECL_CONSPRESOL(consPresolComponents)
SCIP_VAR ** vars
#define SCIPallocBufferArray(scip, ptr, num)
Definition: scip_mem.h:124
SCIP_RETCODE SCIPsetSolVal(SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var, SCIP_Real val)
Definition: scip_sol.c:1221
public data structures and miscellaneous methods
static SCIP_RETCODE solveComponent(COMPONENT *component, SCIP_Bool lastcomponent, SCIP_RESULT *result)
SCIP_RETCODE SCIPfreeTransform(SCIP *scip)
Definition: scip_solve.c:3469
SCIP_RETCODE SCIPcheckSol(SCIP *scip, SCIP_SOL *sol, SCIP_Bool printreason, SCIP_Bool completely, SCIP_Bool checkbounds, SCIP_Bool checkintegrality, SCIP_Bool checklprows, SCIP_Bool *feasible)
Definition: scip_sol.c:3450
static SCIP_RETCODE findComponents(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata, SCIP_Real *fixedvarsobjsum, SCIP_VAR **sortedvars, SCIP_CONS **sortedconss, int *compstartsvars, int *compstartsconss, int *nsortedvars, int *nsortedconss, int *ncomponents, int *ncompsminsize, int *ncompsmaxsize)
#define SCIP_Bool
Definition: def.h:93
static SCIP_RETCODE createConsComponents(SCIP *scip, SCIP_CONS **cons, const char *name, PROBLEM *problem)
int SCIPgetNImplVars(SCIP *scip)
Definition: scip_prob.c:2135
#define DEFAULT_MINSIZE
char * name
Definition: struct_cons.h:49
static SCIP_RETCODE fillDigraph(SCIP *scip, SCIP_DIGRAPH *digraph, SCIP_CONS **conss, int nconss, int *unfixedvarpos, int nunfixedvars, int *firstvaridxpercons, SCIP_Bool *success)
enum SCIP_Status SCIP_STATUS
Definition: type_stat.h:67
#define DEFAULT_FEASTOLFACTOR
#define consCheckComponents
int SCIPgetDepth(SCIP *scip)
Definition: scip_tree.c:670
SCIP_Real SCIPgetGap(SCIP *scip)
static SCIP_RETCODE initComponent(PROBLEM *problem)
void SCIPsolSetHeur(SCIP_SOL *sol, SCIP_HEUR *heur)
Definition: sol.c:2658
struct Problem PROBLEM
#define SCIPdebugSolIsValidInSubtree(scip, isvalidinsubtree)
Definition: debug.h:300
#define MAX(x, y)
Definition: tclique_def.h:92
SCIP_CONSHDLR * SCIPconsGetHdlr(SCIP_CONS *cons)
Definition: cons.c:8110
methods for debugging
SCIP_RETCODE SCIPsetIntParam(SCIP *scip, const char *name, int value)
Definition: scip_param.c:487
#define CONSHDLR_PROPFREQ
SCIP_RETCODE SCIPfreeSol(SCIP *scip, SCIP_SOL **sol)
Definition: scip_sol.c:985
SCIP_Bool SCIPconsIsChecked(SCIP_CONS *cons)
Definition: cons.c:8289
static SCIP_DECL_CONSPROP(consPropComponents)
SCIP_Bool SCIPconsIsInitial(SCIP_CONS *cons)
Definition: cons.c:8259
SCIP_Real SCIPvarGetObj(SCIP_VAR *var)
Definition: var.c:17771
int SCIPgetNSols(SCIP *scip)
Definition: scip_sol.c:2214
SCIP_Bool SCIPallowWeakDualReds(SCIP *scip)
Definition: scip_var.c:8656
SCIP_RETCODE SCIPfixVar(SCIP *scip, SCIP_VAR *var, SCIP_Real fixedval, SCIP_Bool *infeasible, SCIP_Bool *fixed)
Definition: scip_var.c:8276
SCIP_Real SCIPgetSolOrigObj(SCIP *scip, SCIP_SOL *sol)
Definition: scip_sol.c:1444
SCIP_RETCODE SCIPfixParam(SCIP *scip, const char *name)
Definition: scip_param.c:367
SCIP_Bool SCIPisInfinity(SCIP *scip, SCIP_Real val)
int SCIPgetNBinVars(SCIP *scip)
Definition: scip_prob.c:2045
int SCIPconshdlrGetNActiveConss(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4631
SCIP_Bool SCIPinProbing(SCIP *scip)
Definition: scip_probing.c:97
public methods for variable pricer plugins
int SCIPgetNVars(SCIP *scip)
Definition: scip_prob.c:2000
#define SCIP_REAL_MAX
Definition: def.h:187
SCIP_RETCODE SCIPupdateLocalLowerbound(SCIP *scip, SCIP_Real newbound)
Definition: scip_prob.c:3704
SCIP_RETCODE SCIPpqueueCreate(SCIP_PQUEUE **pqueue, int initsize, SCIP_Real sizefac, SCIP_DECL_SORTPTRCOMP((*ptrcomp)), SCIP_DECL_PQUEUEELEMCHGPOS((*elemchgpos)))
Definition: misc.c:1245
SCIP_RETCODE SCIPaddSol(SCIP *scip, SCIP_SOL *sol, SCIP_Bool *stored)
Definition: scip_sol.c:2935
methods for sorting joint arrays of various types
SCIP_RETCODE SCIPcopyProb(SCIP *sourcescip, SCIP *targetscip, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_Bool global, const char *name)
Definition: scip_copy.c:527
general public methods
SCIP_VAR ** fixedvars
SCIP_SOL * SCIPgetBestSol(SCIP *scip)
Definition: scip_sol.c:2313
SCIP_Bool SCIPisGT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public methods for solutions
SCIP_Longint SCIPgetMemUsed(SCIP *scip)
Definition: scip_mem.c:100
SCIP_RETCODE SCIPpqueueInsert(SCIP_PQUEUE *pqueue, void *elem)
Definition: misc.c:1344
SCIP_RETCODE SCIPgetVarCopy(SCIP *sourcescip, SCIP *targetscip, SCIP_VAR *sourcevar, SCIP_VAR **targetvar, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_Bool global, SCIP_Bool *success)
Definition: scip_copy.c:711
SCIP_CONSDATA * SCIPconsGetData(SCIP_CONS *cons)
Definition: cons.c:8120
int SCIPgetNConss(SCIP *scip)
Definition: scip_prob.c:3050
static SCIP_RETCODE componentCreateSubscip(COMPONENT *component, SCIP_CONSHDLRDATA *conshdlrdata, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_CONS **conss, int nconss, SCIP_Bool *success)
static SCIP_RETCODE sortComponents(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata, SCIP_DIGRAPH *digraph, SCIP_CONS **conss, SCIP_VAR **vars, int *varcomponent, int *conscomponent, int nconss, int nvars, int *firstvaridxpercons, int *ncompsminsize, int *ncompsmaxsize)
public methods for the probing mode
SCIP_RETCODE SCIPreleaseCons(SCIP *scip, SCIP_CONS **cons)
Definition: scip_cons.c:1119
SCIP_SOL * workingsol
SCIP_Real fixedvarsobjsum
SCIP_RETCODE SCIPsetConshdlrPresol(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSPRESOL((*conspresol)), int maxprerounds, SCIP_PRESOLTIMING presoltiming)
Definition: scip_cons.c:534
public methods for message output
SCIP_Real SCIPretransformObj(SCIP *scip, SCIP_Real obj)
Definition: scip_sol.c:1576
static SCIP_DECL_CONSINITSOL(consInitsolComponents)
#define DEFAULT_MINRELSIZE
SCIP_Longint SCIPgetMemExternEstim(SCIP *scip)
Definition: scip_mem.c:126
SCIP_VAR ** SCIPgetVars(SCIP *scip)
Definition: scip_prob.c:1955
static SCIP_RETCODE createAndSplitProblem(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata, SCIP_Real fixedvarsobjsum, SCIP_VAR **sortedvars, SCIP_CONS **sortedconss, int *compstartsvars, int *compstartsconss, int ncomponents, PROBLEM **problem)
#define SCIP_Real
Definition: def.h:186
SCIP_Bool SCIPconsIsModifiable(SCIP_CONS *cons)
Definition: cons.c:8339
SCIP_Bool SCIPisStopped(SCIP *scip)
Definition: scip_general.c:703
static SCIP_RETCODE solveProblem(PROBLEM *problem, SCIP_RESULT *result)
SCIP * subscip
public methods for message handling
SCIP_Bool SCIPconsIsEnforced(SCIP_CONS *cons)
Definition: cons.c:8279
#define DEFAULT_NODELIMIT
public methods for data structures
SCIP_Bool SCIPconsIsSeparated(SCIP_CONS *cons)
Definition: cons.c:8269
#define SCIP_Longint
Definition: def.h:171
int SCIPvarGetIndex(SCIP_VAR *var)
Definition: var.c:17603
#define SCIPdebugAddSolVal(scip, var, val)
Definition: debug.h:298
#define CONSHDLR_DESC
SCIP_VARTYPE SCIPvarGetType(SCIP_VAR *var)
Definition: var.c:17429
SCIP_RETCODE SCIPtransformProb(SCIP *scip)
Definition: scip_solve.c:367
#define SCIPdebugSolIsEnabled(scip)
Definition: debug.h:303
SCIP_Bool SCIPisZero(SCIP *scip, SCIP_Real val)
SCIP_Bool SCIPisLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
int lastbestsolindex
static SCIP_RETCODE initProblem(SCIP *scip, PROBLEM **problem, SCIP_Real fixedvarsobjsum, int ncomponents)
struct SCIP_ConshdlrData SCIP_CONSHDLRDATA
Definition: type_cons.h:64
SCIP_VAR ** fixedsubvars
static SCIP_DECL_CONSFREE(conshdlrFreeComponents)
SCIP_Real SCIPvarGetUbLocal(SCIP_VAR *var)
Definition: var.c:17989
#define CONSHDLR_NEEDSCONS
SCIP_RETCODE SCIPinterruptSolve(SCIP *scip)
Definition: scip_solve.c:3553
#define BMSclearMemoryArray(ptr, num)
Definition: memory.h:132
SCIP_Bool SCIPisSumLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public methods for primal heuristics
#define CONSHDLR_PROP_TIMING
void SCIPaddNNodes(SCIP *scip, SCIP_Longint nnodes)
void SCIPdigraphFree(SCIP_DIGRAPH **digraph)
Definition: misc.c:7480
SCIP_Longint SCIPgetNNodes(SCIP *scip)
#define SCIPdebugSolEnable(scip)
Definition: debug.h:301
public methods for global and local (sub)problems
SCIP_RETCODE SCIPgetActiveVars(SCIP *scip, SCIP_VAR **vars, int *nvars, int varssize, int *requiredsize)
Definition: scip_var.c:1830
#define consEnfolpComponents
SCIP_Real SCIPgetSolVal(SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var)
Definition: scip_sol.c:1361
static SCIP_RETCODE createSubscip(SCIP *scip, SCIP_CONSHDLRDATA *conshdlrdata, SCIP **subscip)
int SCIPsolGetIndex(SCIP_SOL *sol)
Definition: sol.c:2644
SCIP_Bool SCIPallowStrongDualReds(SCIP *scip)
Definition: scip_var.c:8629
SCIP_RETCODE SCIPaddRealParam(SCIP *scip, const char *name, const char *desc, SCIP_Real *valueptr, SCIP_Bool isadvanced, SCIP_Real defaultvalue, SCIP_Real minvalue, SCIP_Real maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:139
SCIP_RETCODE SCIPsetLongintParam(SCIP *scip, const char *name, SCIP_Longint value)
Definition: scip_param.c:545
SCIP_Bool SCIPvarIsActive(SCIP_VAR *var)
Definition: var.c:17593
SCIP_RETCODE SCIPfree(SCIP **scip)
Definition: scip_general.c:324
SCIP_RETCODE SCIPcreateSol(SCIP *scip, SCIP_SOL **sol, SCIP_HEUR *heur)
Definition: scip_sol.c:328
#define SCIPreallocBufferArray(scip, ptr, num)
Definition: scip_mem.h:128
void SCIPvarMarkDeleteGlobalStructures(SCIP_VAR *var)
Definition: var.c:17521
SCIP_RETCODE SCIPsetConshdlrProp(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_DECL_CONSPROP((*consprop)), int propfreq, SCIP_Bool delayprop, SCIP_PROPTIMING proptiming)
Definition: scip_cons.c:275
memory allocation routines