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    	/*                                                                           */
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9    	/*  you may not use this file except in compliance with the License.         */
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11   	/*                                                                           */
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13   	/*                                                                           */
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19   	/*                                                                           */
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21   	/*  along with SCIP; see the file LICENSE. If not visit scipopt.org.         */
22   	/*                                                                           */
23   	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24   	
25   	/**@file   struct_var.h
26   	 * @ingroup INTERNALAPI
27   	 * @brief  datastructures for problem variables
28   	 * @author Tobias Achterberg
29   	 */
30   	
31   	/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32   	
33   	#ifndef __SCIP_STRUCT_VAR_H__
34   	#define __SCIP_STRUCT_VAR_H__
35   	
36   	
37   	#include "scip/def.h"
38   	#include "scip/type_history.h"
39   	#include "scip/type_event.h"
40   	#include "scip/type_var.h"
41   	#include "scip/type_implics.h"
42   	#include "scip/type_cons.h"
43   	#include "scip/type_prop.h"
44   	#include "scip/type_lp.h"
45   	
46   	#ifdef __cplusplus
47   	extern "C" {
48   	#endif
49   	
50   	/** hole in a domain */
51   	struct SCIP_Hole
52   	{
53   	   SCIP_Real             left;               /**< left bound of open interval defining the hole (left,right) */
54   	   SCIP_Real             right;              /**< right bound of open interval defining the hole (left,right) */
55   	};
56   	
57   	/** list of domain holes */
58   	struct SCIP_Holelist
59   	{
60   	   SCIP_HOLE             hole;               /**< this hole */
61   	   SCIP_HOLELIST*        next;               /**< next hole in list */
62   	};
63   	
64   	/** change in a hole list */
65   	struct SCIP_HoleChg
66   	{
67   	   SCIP_HOLELIST**       ptr;                /**< changed list pointer */
68   	   SCIP_HOLELIST*        newlist;            /**< new value of list pointer */
69   	   SCIP_HOLELIST*        oldlist;            /**< old value of list pointer */
70   	};
71   	
72   	/** data for branching decision bound changes */
73   	struct SCIP_BranchingData
74   	{
75   	   SCIP_Real             lpsolval;           /**< sol val of var in last LP prior to bound change, or SCIP_INVALID if unknown */
76   	};
77   	
78   	/** data for inferred bound changes */
79   	struct SCIP_InferenceData
80   	{
81   	   SCIP_VAR*             var;                /**< variable that was changed (parent of var, or var itself) */
82   	   union
83   	   {
84   	      SCIP_CONS*         cons;               /**< constraint that inferred this bound change, or NULL */
85   	      SCIP_PROP*         prop;               /**< propagator that inferred this bound change, or NULL */
86   	   } reason;
87   	   int                   info;               /**< user information for inference to help resolving the conflict */
88   	};
89   	
90   	/** change in one bound of a variable */
91   	struct SCIP_BoundChg
92   	{
93   	   SCIP_Real             newbound;           /**< new value for bound */
94   	   union
95   	   {
96   	      SCIP_BRANCHINGDATA branchingdata;      /**< data for branching decisions */
97   	      SCIP_INFERENCEDATA inferencedata;      /**< data for inferred bound changes */
98   	   } data;
99   	   SCIP_VAR*             var;                /**< active variable to change the bounds for */
100  	   unsigned int          boundchgtype:2;     /**< bound change type: branching decision or inferred bound change */
101  	   unsigned int          boundtype:1;        /**< type of bound for var: lower or upper bound */
102  	   unsigned int          inferboundtype:1;   /**< type of bound for inference var (see inference data): lower or upper bound */
103  	   unsigned int          applied:1;          /**< was this bound change applied at least once? */
104  	   unsigned int          redundant:1;        /**< is this bound change redundant? */
105  	};
106  	
107  	/** bound change index representing the time of the bound change in path from root to current node */
108  	struct SCIP_BdChgIdx
109  	{
110  	   int                   depth;              /**< depth of node where the bound change was created */
111  	   int                   pos;                /**< position of bound change in node's domchg array */
112  	};
113  	
114  	/** bound change information to track bound changes from root node to current node */
115  	struct SCIP_BdChgInfo
116  	{
117  	   SCIP_Real             oldbound;           /**< old value for bound */
118  	   SCIP_Real             newbound;           /**< new value for bound */
119  	   SCIP_VAR*             var;                /**< active variable that changed the bounds */
120  	   SCIP_INFERENCEDATA    inferencedata;      /**< data for inferred bound changes */
121  	   SCIP_BDCHGIDX         bdchgidx;           /**< bound change index in path from root to current node */
122  	   unsigned int          pos:27;             /**< position in the variable domain change array */
123  	   unsigned int          boundchgtype:2;     /**< bound change type: branching decision or inferred bound change */
124  	   unsigned int          boundtype:1;        /**< type of bound for var: lower or upper bound */
125  	   unsigned int          inferboundtype:1;   /**< type of bound for inference var (see inference data): lower or upper bound */
126  	   unsigned int          redundant:1;        /**< does the bound change info belong to a redundant bound change? */
127  	};
128  	
129  	/** tracks changes of the variables' domains (static arrays, bound changes only) */
130  	struct SCIP_DomChgBound
131  	{
132  	   unsigned int          nboundchgs:30;      /**< number of bound changes (must be first structure entry!) */
133  	   unsigned int          domchgtype:2;       /**< type of domain change data (must be first structure entry!) */
134  	   SCIP_BOUNDCHG*        boundchgs;          /**< array with changes in bounds of variables */
135  	};
136  	
137  	/** tracks changes of the variables' domains (static arrays, bound and hole changes) */
138  	struct SCIP_DomChgBoth
139  	{
140  	   unsigned int          nboundchgs:30;      /**< number of bound changes (must be first structure entry!) */
141  	   unsigned int          domchgtype:2;       /**< type of domain change data (must be first structure entry!) */
142  	   SCIP_BOUNDCHG*        boundchgs;          /**< array with changes in bounds of variables */
143  	   SCIP_HOLECHG*         holechgs;           /**< array with changes in hole lists */
144  	   int                   nholechgs;          /**< number of hole list changes */
145  	};
146  	
147  	/** tracks changes of the variables' domains (dynamic arrays) */
148  	struct SCIP_DomChgDyn
149  	{
150  	   unsigned int          nboundchgs:30;      /**< number of bound changes (must be first structure entry!) */
151  	   unsigned int          domchgtype:2;       /**< type of domain change data (must be first structure entry!) */
152  	   SCIP_BOUNDCHG*        boundchgs;          /**< array with changes in bounds of variables */
153  	   SCIP_HOLECHG*         holechgs;           /**< array with changes in hole lists */
154  	   int                   nholechgs;          /**< number of hole list changes */
155  	   int                   boundchgssize;      /**< size of bound changes array */
156  	   int                   holechgssize;       /**< size of hole changes array */
157  	};
158  	
159  	/** tracks changes of the variables' domains */
160  	union SCIP_DomChg
161  	{
162  	   SCIP_DOMCHGBOUND      domchgbound;        /**< bound changes */
163  	   SCIP_DOMCHGBOTH       domchgboth;         /**< bound and hole changes */
164  	   SCIP_DOMCHGDYN        domchgdyn;          /**< bound and hole changes with dynamic arrays */
165  	};
166  	
167  	/** domain of a variable */
168  	struct SCIP_Dom
169  	{
170  	   SCIP_Real             lb;                 /**< lower bounds of variables */
171  	   SCIP_Real             ub;                 /**< upper bounds of variables */
172  	   SCIP_HOLELIST*        holelist;           /**< list of holes */
173  	};
174  	
175  	/** original variable information */
176  	struct SCIP_Original
177  	{
178  	   SCIP_DOM              origdom;            /**< domain of variable in original problem */
179  	   SCIP_VAR*             transvar;           /**< pointer to representing transformed variable */
180  	};
181  	
182  	/** aggregation information: x = a*y + c */
183  	struct SCIP_Aggregate
184  	{
185  	   SCIP_Real             scalar;             /**< multiplier a in aggregation */
186  	   SCIP_Real             constant;           /**< constant shift c in aggregation */
187  	   SCIP_VAR*             var;                /**< variable y in aggregation */
188  	};
189  	
190  	/** multiple aggregation information: x = a_1*y_1 + ... + a_k*y_k + c */
191  	struct SCIP_Multaggr
192  	{
193  	   SCIP_Real             constant;           /**< constant shift c in multiple aggregation */
194  	   SCIP_Real*            scalars;            /**< multipliers a in multiple aggregation */
195  	   SCIP_VAR**            vars;               /**< variables y in multiple aggregation */
196  	   int                   nvars;              /**< number of variables in aggregation */
197  	   int                   varssize;           /**< size of vars and scalars arrays */
198  	};
199  	
200  	/** negation information: x' = c - x */
201  	struct SCIP_Negate
202  	{
203  	   SCIP_Real             constant;           /**< constant shift c in negation */
204  	};
205  	
206  	/** variable of the problem */
207  	struct SCIP_Var
208  	{
209  	   SCIP_Real             obj;                /**< objective function value of variable (might be changed temporarily in probing mode)*/
210  	   SCIP_Real             unchangedobj;       /**< unchanged objective function value of variable (ignoring temporary changes in probing mode) */
211  	   SCIP_Real             branchfactor;       /**< factor to weigh variable's branching score with */
212  	   SCIP_Real             rootsol;            /**< last primal solution of variable in root node, or zero */
213  	   SCIP_Real             bestrootsol;        /**< best primal solution of variable in root node, or zero, w.r.t. root LP value and root reduced cost */
214  	   SCIP_Real             bestrootredcost;    /**< best reduced costs of variable in root node, or zero, w.r.t. root LP value and root solution value */
215  	   SCIP_Real             bestrootlpobjval;   /**< best root LP objective value, or SCIP_INVALID, w.r.t. root solution value and root reduced cost */
216  	   SCIP_Real             relaxsol;           /**< primal solution of variable in current relaxation solution, or SCIP_INVALID */
217  	   SCIP_Real             nlpsol;             /**< primal solution of variable in current NLP solution, or SCIP_INVALID */
218  	   SCIP_Real             primsolavg;         /**< weighted average of all values of variable in primal feasible solutions */
219  	   SCIP_Real             conflictlb;         /**< maximal lower bound of variable in the current conflict */
220  	   SCIP_Real             conflictub;         /**< minimal upper bound of variable in the current conflict */
221  	   SCIP_Real             conflictrelaxedlb;  /**< maximal relaxed lower bound of variable in the current conflict (conflictrelaxedlb <= conflictlb) */
222  	   SCIP_Real             conflictrelaxedub;  /**< minimal relaxed upper bound of variable in the current conflict (conflictrelaxedub >= conflictub) */
223  	   SCIP_Real             lazylb;             /**< global lower bound that is ensured by constraints and has not to be added to the LP */
224  	   SCIP_Real             lazyub;             /**< global upper bound that is ensured by constraints and has not to be added to the LP */
225  	   SCIP_DOM              glbdom;             /**< domain of variable in global problem */
226  	   SCIP_DOM              locdom;             /**< domain of variable in current subproblem */
227  	   union
228  	   {
229  	      SCIP_ORIGINAL      original;           /**< original variable information */
230  	      SCIP_COL*          col;                /**< LP column (for column variables) */
231  	      SCIP_AGGREGATE     aggregate;          /**< aggregation information (for aggregated variables) */
232  	      SCIP_MULTAGGR      multaggr;           /**< multiple aggregation information (for multiple aggregated variables) */
233  	      SCIP_NEGATE        negate;             /**< negation information (for negated variables) */
234  	   } data;
235  	   char*                 name;               /**< name of the variable */
236  	   SCIP_DECL_VARCOPY     ((*varcopy));       /**< copies variable data if wanted to subscip, or NULL */
237  	   SCIP_DECL_VARDELORIG  ((*vardelorig));    /**< frees user data of original variable */
238  	   SCIP_DECL_VARTRANS    ((*vartrans));      /**< creates transformed user data by transforming original user data */
239  	   SCIP_DECL_VARDELTRANS ((*vardeltrans));   /**< frees user data of transformed variable */
240  	   SCIP_VARDATA*         vardata;            /**< user data for this specific variable */
241  	   SCIP_VAR**            parentvars;         /**< parent variables in the aggregation tree */
242  	   SCIP_VAR*             negatedvar;         /**< pointer to the variables negation: x' = lb + ub - x, or NULL if not created */
243  	   SCIP_VBOUNDS*         vlbs;               /**< variable lower bounds x >= b*y + d */
244  	   SCIP_VBOUNDS*         vubs;               /**< variable upper bounds x <= b*y + d */
245  	   SCIP_IMPLICS*         implics;            /**< implications y >=/<= b following from x <= 0 and x >= 1 (x binary), or NULL if x is not binary */
246  	   SCIP_CLIQUELIST*      cliquelist;         /**< list of cliques the variable and its negation is member of */
247  	   SCIP_EVENTFILTER*     eventfilter;        /**< event filter for events concerning this variable; not for ORIGINAL vars */
248  	   SCIP_BDCHGINFO*       lbchginfos;         /**< bound change informations for lower bound changes from root to current node */
249  	   SCIP_BDCHGINFO*       ubchginfos;         /**< bound change informations for upper bound changes from root to current node */
250  	   SCIP_HISTORY*         history;            /**< branching and inference history information */
251  	   SCIP_HISTORY*         historycrun;        /**< branching and inference history information for current run */
252  	   SCIP_VALUEHISTORY*    valuehistory;       /**< branching and inference history information which are value based, or NULL if not used */
253  	   SCIP_Longint          closestvblpcount;   /**< LP count for which the closestvlbidx/closestvubidx entries are valid */
254  	   int                   index;              /**< consecutively numbered variable identifier */
255  	   int                   probindex;          /**< array position in problems vars array, or -1 if not assigned to a problem */
256  	   int                   pseudocandindex;    /**< array position in pseudo branching candidates array, or -1 */
257  	   int                   eventqueueindexobj; /**< array position in event queue of objective change event, or -1 */
258  	   int                   eventqueueindexlb;  /**< array position in event queue of lower bound change event, or -1 */
259  	   int                   eventqueueindexub;  /**< array position in event queue of upper bound change event, or -1 */
260  	   int                   parentvarssize;     /**< available slots in parentvars array */
261  	   int                   nparentvars;        /**< number of parent variables in aggregation tree (used slots of parentvars) */
262  	   int                   nuses;              /**< number of times, this variable is referenced */
263  	   int                   nlocksdown[NLOCKTYPES]; /**< array of variable locks for rounding down; if zero, rounding down is always feasible */
264  	   int                   nlocksup[NLOCKTYPES];   /**< array of variable locks for rounding up; if zero, rounding up is always feasible */
265  	   int                   branchpriority;     /**< priority of the variable for branching */
266  	   int                   lbchginfossize;     /**< available slots in lbchginfos array */
267  	   int                   nlbchginfos;        /**< number of lower bound changes from root node to current node */
268  	   int                   ubchginfossize;     /**< available slots in ubchginfos array */
269  	   int                   nubchginfos;        /**< number of upper bound changes from root node to current node */
270  	   int                   conflictlbcount;    /**< number of last conflict, the lower bound was member of */
271  	   int                   conflictubcount;    /**< number of last conflict, the upper bound was member of */
272  	   int                   closestvlbidx;      /**< index of closest VLB variable in current LP solution, or -1 */
273  	   int                   closestvubidx;      /**< index of closest VUB variable in current LP solution, or -1 */
274  	   unsigned int          initial:1;          /**< TRUE iff var's column should be present in the initial root LP */
275  	   unsigned int          removable:1;        /**< TRUE iff var's column is removable from the LP (due to aging or cleanup) */
276  	   unsigned int          deletable:1;        /**< TRUE iff the variable is removable from the problem */
277  	   unsigned int          deleted:1;          /**< TRUE iff variable was marked for deletion from the problem */
278  	   unsigned int          donotaggr:1;        /**< TRUE iff variable is not allowed to be aggregated */
279  	   unsigned int          donotmultaggr:1;    /**< TRUE iff variable is not allowed to be multi-aggregated */
280  	   unsigned int          vartype:2;          /**< type of variable: binary, integer, implicit integer, continuous */
281  	   unsigned int          varstatus:3;        /**< status of variable: original, loose, column, fixed, aggregated, multiaggregated, negated */
282  	   unsigned int          pseudocostflag:2;   /**< temporary flag used in pseudo cost update */
283  	   unsigned int          branchdirection:2;  /**< preferred branching direction of the variable (downwards, upwards, auto) */
284  	   unsigned int          eventqueueimpl:1;   /**< is an IMPLADDED event on this variable currently in the event queue? */
285  	   unsigned int          delglobalstructs:1; /**< is variable marked to be removed from global structures (cliques etc.)? */
286  	   unsigned int          relaxationonly:1;   /**< TRUE if variable has been introduced only to define a relaxation */
287  	#ifndef NDEBUG
288  	   SCIP*                 scip;               /**< SCIP data structure */
289  	#endif
290  	};
291  	
292  	#ifdef __cplusplus
293  	}
294  	#endif
295  	
296  	#endif
297