1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
6 /* Copyright (C) 2002-2021 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SCIP is distributed under the terms of the ZIB Academic License. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15
16 /**@file struct_var.h
17 * @ingroup INTERNALAPI
18 * @brief datastructures for problem variables
19 * @author Tobias Achterberg
20 */
21
22 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
23
24 #ifndef __SCIP_STRUCT_VAR_H__
25 #define __SCIP_STRUCT_VAR_H__
26
27
28 #include "scip/def.h"
29 #include "scip/type_history.h"
30 #include "scip/type_event.h"
31 #include "scip/type_var.h"
32 #include "scip/type_implics.h"
33 #include "scip/type_cons.h"
34 #include "scip/type_prop.h"
35 #include "scip/type_lp.h"
36
37 #ifdef __cplusplus
38 extern "C" {
39 #endif
40
41 /** hole in a domain */
42 struct SCIP_Hole
43 {
44 SCIP_Real left; /**< left bound of open interval defining the hole (left,right) */
45 SCIP_Real right; /**< right bound of open interval defining the hole (left,right) */
46 };
47
48 /** list of domain holes */
49 struct SCIP_Holelist
50 {
51 SCIP_HOLE hole; /**< this hole */
52 SCIP_HOLELIST* next; /**< next hole in list */
53 };
54
55 /** change in a hole list */
56 struct SCIP_HoleChg
57 {
58 SCIP_HOLELIST** ptr; /**< changed list pointer */
59 SCIP_HOLELIST* newlist; /**< new value of list pointer */
60 SCIP_HOLELIST* oldlist; /**< old value of list pointer */
61 };
62
63 /** data for branching decision bound changes */
64 struct SCIP_BranchingData
65 {
66 SCIP_Real lpsolval; /**< sol val of var in last LP prior to bound change, or SCIP_INVALID if unknown */
67 };
68
69 /** data for infered bound changes */
70 struct SCIP_InferenceData
71 {
72 SCIP_VAR* var; /**< variable that was changed (parent of var, or var itself) */
73 union
74 {
75 SCIP_CONS* cons; /**< constraint that infered this bound change, or NULL */
76 SCIP_PROP* prop; /**< propagator that infered this bound change, or NULL */
77 } reason;
78 int info; /**< user information for inference to help resolving the conflict */
79 };
80
81 /** change in one bound of a variable */
82 struct SCIP_BoundChg
83 {
84 SCIP_Real newbound; /**< new value for bound */
85 union
86 {
87 SCIP_BRANCHINGDATA branchingdata; /**< data for branching decisions */
88 SCIP_INFERENCEDATA inferencedata; /**< data for infered bound changes */
89 } data;
90 SCIP_VAR* var; /**< active variable to change the bounds for */
91 unsigned int boundchgtype:2; /**< bound change type: branching decision or infered bound change */
92 unsigned int boundtype:1; /**< type of bound for var: lower or upper bound */
93 unsigned int inferboundtype:1; /**< type of bound for inference var (see inference data): lower or upper bound */
94 unsigned int applied:1; /**< was this bound change applied at least once? */
95 unsigned int redundant:1; /**< is this bound change redundant? */
96 };
97
98 /** bound change index representing the time of the bound change in path from root to current node */
99 struct SCIP_BdChgIdx
100 {
101 int depth; /**< depth of node where the bound change was created */
102 int pos; /**< position of bound change in node's domchg array */
103 };
104
105 /** bound change information to track bound changes from root node to current node */
106 struct SCIP_BdChgInfo
107 {
108 SCIP_Real oldbound; /**< old value for bound */
109 SCIP_Real newbound; /**< new value for bound */
110 SCIP_VAR* var; /**< active variable that changed the bounds */
111 SCIP_INFERENCEDATA inferencedata; /**< data for infered bound changes */
112 SCIP_BDCHGIDX bdchgidx; /**< bound change index in path from root to current node */
113 unsigned int pos:27; /**< position in the variable domain change array */
114 unsigned int boundchgtype:2; /**< bound change type: branching decision or infered bound change */
115 unsigned int boundtype:1; /**< type of bound for var: lower or upper bound */
116 unsigned int inferboundtype:1; /**< type of bound for inference var (see inference data): lower or upper bound */
117 unsigned int redundant:1; /**< does the bound change info belong to a redundant bound change? */
118 };
119
120 /** tracks changes of the variables' domains (static arrays, bound changes only) */
121 struct SCIP_DomChgBound
122 {
123 unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
124 unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
125 SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
126 };
127
128 /** tracks changes of the variables' domains (static arrays, bound and hole changes) */
129 struct SCIP_DomChgBoth
130 {
131 unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
132 unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
133 SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
134 SCIP_HOLECHG* holechgs; /**< array with changes in hole lists */
135 int nholechgs; /**< number of hole list changes */
136 };
137
138 /** tracks changes of the variables' domains (dynamic arrays) */
139 struct SCIP_DomChgDyn
140 {
141 unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
142 unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
143 SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
144 SCIP_HOLECHG* holechgs; /**< array with changes in hole lists */
145 int nholechgs; /**< number of hole list changes */
146 int boundchgssize; /**< size of bound changes array */
147 int holechgssize; /**< size of hole changes array */
148 };
149
150 /** tracks changes of the variables' domains */
151 union SCIP_DomChg
152 {
153 SCIP_DOMCHGBOUND domchgbound; /**< bound changes */
154 SCIP_DOMCHGBOTH domchgboth; /**< bound and hole changes */
155 SCIP_DOMCHGDYN domchgdyn; /**< bound and hole changes with dynamic arrays */
156 };
157
158 /** domain of a variable */
159 struct SCIP_Dom
160 {
161 SCIP_Real lb; /**< lower bounds of variables */
162 SCIP_Real ub; /**< upper bounds of variables */
163 SCIP_HOLELIST* holelist; /**< list of holes */
164 };
165
166 /** original variable information */
167 struct SCIP_Original
168 {
169 SCIP_DOM origdom; /**< domain of variable in original problem */
170 SCIP_VAR* transvar; /**< pointer to representing transformed variable */
171 };
172
173 /** aggregation information: x = a*y + c */
174 struct SCIP_Aggregate
175 {
176 SCIP_Real scalar; /**< multiplier a in aggregation */
177 SCIP_Real constant; /**< constant shift c in aggregation */
178 SCIP_VAR* var; /**< variable y in aggregation */
179 };
180
181 /** multiple aggregation information: x = a_1*y_1 + ... + a_k*y_k + c */
182 struct SCIP_Multaggr
183 {
184 SCIP_Real constant; /**< constant shift c in multiple aggregation */
185 SCIP_Real* scalars; /**< multipliers a in multiple aggregation */
186 SCIP_VAR** vars; /**< variables y in multiple aggregation */
187 int nvars; /**< number of variables in aggregation */
188 int varssize; /**< size of vars and scalars arrays */
189 };
190
191 /** negation information: x' = c - x */
192 struct SCIP_Negate
193 {
194 SCIP_Real constant; /**< constant shift c in negation */
195 };
196
197 /** variable of the problem */
198 struct SCIP_Var
199 {
200 SCIP_Real obj; /**< objective function value of variable (might be changed temporarily in probing mode)*/
201 SCIP_Real unchangedobj; /**< unchanged objective function value of variable (ignoring temporary changes in probing mode) */
202 SCIP_Real branchfactor; /**< factor to weigh variable's branching score with */
203 SCIP_Real rootsol; /**< last primal solution of variable in root node, or zero */
204 SCIP_Real bestrootsol; /**< best primal solution of variable in root node, or zero, w.r.t. root LP value and root reduced cost */
205 SCIP_Real bestrootredcost; /**< best reduced costs of variable in root node, or zero, w.r.t. root LP value and root solution value */
206 SCIP_Real bestrootlpobjval; /**< best root LP objective value, or SCIP_INVALID, w.r.t. root solution value and root reduced cost */
207 SCIP_Real relaxsol; /**< primal solution of variable in current relaxation solution, or SCIP_INVALID */
208 SCIP_Real nlpsol; /**< primal solution of variable in current NLP solution, or SCIP_INVALID */
209 SCIP_Real primsolavg; /**< weighted average of all values of variable in primal feasible solutions */
210 SCIP_Real conflictlb; /**< maximal lower bound of variable in the current conflict */
211 SCIP_Real conflictub; /**< minimal upper bound of variable in the current conflict */
212 SCIP_Real conflictrelaxedlb; /**< minimal relaxed lower bound of variable in the current conflict (conflictrelqxlb <= conflictlb) */
213 SCIP_Real conflictrelaxedub; /**< minimal release upper bound of variable in the current conflict (conflictrelqxlb <= conflictlb) */
214 SCIP_Real lazylb; /**< global lower bound that is ensured by constraints and has not to be added to the LP */
215 SCIP_Real lazyub; /**< global upper bound that is ensured by constraints and has not to be added to the LP */
216 SCIP_DOM glbdom; /**< domain of variable in global problem */
217 SCIP_DOM locdom; /**< domain of variable in current subproblem */
218 union
219 {
220 SCIP_ORIGINAL original; /**< original variable information */
221 SCIP_COL* col; /**< LP column (for column variables) */
222 SCIP_AGGREGATE aggregate; /**< aggregation information (for aggregated variables) */
223 SCIP_MULTAGGR multaggr; /**< multiple aggregation information (for multiple aggregated variables) */
224 SCIP_NEGATE negate; /**< negation information (for negated variables) */
225 } data;
226 char* name; /**< name of the variable */
227 SCIP_DECL_VARCOPY ((*varcopy)); /**< copies variable data if wanted to subscip, or NULL */
228 SCIP_DECL_VARDELORIG ((*vardelorig)); /**< frees user data of original variable */
229 SCIP_DECL_VARTRANS ((*vartrans)); /**< creates transformed user data by transforming original user data */
230 SCIP_DECL_VARDELTRANS ((*vardeltrans)); /**< frees user data of transformed variable */
231 SCIP_VARDATA* vardata; /**< user data for this specific variable */
232 SCIP_VAR** parentvars; /**< parent variables in the aggregation tree */
233 SCIP_VAR* negatedvar; /**< pointer to the variables negation: x' = lb + ub - x, or NULL if not created */
234 SCIP_VBOUNDS* vlbs; /**< variable lower bounds x >= b*y + d */
235 SCIP_VBOUNDS* vubs; /**< variable upper bounds x <= b*y + d */
236 SCIP_IMPLICS* implics; /**< implications y >=/<= b following from x <= 0 and x >= 1 (x binary), or NULL if x is not binary */
237 SCIP_CLIQUELIST* cliquelist; /**< list of cliques the variable and its negation is member of */
238 SCIP_EVENTFILTER* eventfilter; /**< event filter for events concerning this variable; not for ORIGINAL vars */
239 SCIP_BDCHGINFO* lbchginfos; /**< bound change informations for lower bound changes from root to current node */
240 SCIP_BDCHGINFO* ubchginfos; /**< bound change informations for upper bound changes from root to current node */
241 SCIP_HISTORY* history; /**< branching and inference history information */
242 SCIP_HISTORY* historycrun; /**< branching and inference history information for current run */
243 SCIP_VALUEHISTORY* valuehistory; /**< branching and inference history information which are value based, or NULL if not used */
244 SCIP_Longint closestvblpcount; /**< LP count for which the closestvlbidx/closestvubidx entries are valid */
245 int index; /**< consecutively numbered variable identifier */
246 int probindex; /**< array position in problems vars array, or -1 if not assigned to a problem */
247 int pseudocandindex; /**< array position in pseudo branching candidates array, or -1 */
248 int eventqueueindexobj; /**< array position in event queue of objective change event, or -1 */
249 int eventqueueindexlb; /**< array position in event queue of lower bound change event, or -1 */
250 int eventqueueindexub; /**< array position in event queue of upper bound change event, or -1 */
251 int parentvarssize; /**< available slots in parentvars array */
252 int nparentvars; /**< number of parent variables in aggregation tree (used slots of parentvars) */
253 int nuses; /**< number of times, this variable is referenced */
254 int nlocksdown[NLOCKTYPES]; /**< array of variable locks for rounding down; if zero, rounding down is always feasible */
255 int nlocksup[NLOCKTYPES]; /**< array of variable locks for rounding up; if zero, rounding up is always feasible */
256 int branchpriority; /**< priority of the variable for branching */
257 int lbchginfossize; /**< available slots in lbchginfos array */
258 int nlbchginfos; /**< number of lower bound changes from root node to current node */
259 int ubchginfossize; /**< available slots in ubchginfos array */
260 int nubchginfos; /**< number of upper bound changes from root node to current node */
261 int conflictlbcount; /**< number of last conflict, the lower bound was member of */
262 int conflictubcount; /**< number of last conflict, the upper bound was member of */
263 int closestvlbidx; /**< index of closest VLB variable in current LP solution, or -1 */
264 int closestvubidx; /**< index of closest VUB variable in current LP solution, or -1 */
265 unsigned int initial:1; /**< TRUE iff var's column should be present in the initial root LP */
266 unsigned int removable:1; /**< TRUE iff var's column is removable from the LP (due to aging or cleanup) */
267 unsigned int deletable:1; /**< TRUE iff the variable is removable from the problem */
268 unsigned int deleted:1; /**< TRUE iff variable was marked for deletion from the problem */
269 unsigned int donotaggr:1; /**< TRUE iff variable is not allowed to be aggregated */
270 unsigned int donotmultaggr:1; /**< TRUE iff variable is not allowed to be multi-aggregated */
271 unsigned int vartype:2; /**< type of variable: binary, integer, implicit integer, continuous */
272 unsigned int varstatus:3; /**< status of variable: original, loose, column, fixed, aggregated, multiaggregated, negated */
273 unsigned int pseudocostflag:2; /**< temporary flag used in pseudo cost update */
274 unsigned int branchdirection:2; /**< preferred branching direction of the variable (downwards, upwards, auto) */
275 unsigned int eventqueueimpl:1; /**< is an IMPLADDED event on this variable currently in the event queue? */
276 unsigned int delglobalstructs:1; /**< is variable marked to be removed from global structures (cliques etc.)? */
277 unsigned int relaxationonly:1; /**< TRUE if variable has been introduced only to define a relaxation */
278 #ifndef NDEBUG
279 SCIP* scip; /**< SCIP data structure */
280 #endif
281 };
282
283 #ifdef __cplusplus
284 }
285 #endif
286
287 #endif
288