Detailed Description

LNS heuristic uses the variable lower and upper bounds to determine the search neighborhood.

Author: Timo Berthold; Stefan Heinz; Jens Schulz; Gerald Gamrath

More details about the heuristic can be found in
Structure-Based Primal Heuristics for Mixed Integer Programming
Gerald Gamrath, Timo Berthold, Stefan Heinz, and Michael Winkler
Optimization in the Real World, Volume 13 of the series Mathematics for Industry, pp 37-53
Preliminary version available as ZIB-Report 15-26.

Definition in file heur_vbounds.c.

#include "blockmemshell/memory.h"
#include "scip/heur_locks.h"
#include "scip/heur_vbounds.h"
#include "scip/pub_heur.h"
#include "scip/pub_implics.h"
#include "scip/pub_message.h"
#include "scip/pub_misc.h"
#include "scip/pub_tree.h"
#include "scip/pub_var.h"
#include "scip/scip_branch.h"
#include "scip/scip_cons.h"
#include "scip/scip_copy.h"
#include "scip/scip_general.h"
#include "scip/scip_heur.h"
#include "scip/scip_lp.h"
#include "scip/scip_mem.h"
#include "scip/scip_message.h"
#include "scip/scip_numerics.h"
#include "scip/scip_param.h"
#include "scip/scip_prob.h"
#include "scip/scip_probing.h"
#include "scip/scip_sol.h"
#include "scip/scip_solve.h"
#include "scip/scip_solvingstats.h"
#include "scip/scip_timing.h"
#include "scip/scip_tree.h"
#include "scip/scip_var.h"
#include <string.h>

Go to the source code of this file.

Macros
#define	VBOUNDVARIANT_NOOBJ 0x001u

#define	VBOUNDVARIANT_BESTBOUND 0x002u

#define	VBOUNDVARIANT_WORSTBOUND 0x004u

#define	HEUR_NAME "vbounds"

#define	HEUR_DESC "LNS heuristic uses the variable lower and upper bounds to determine the search neighborhood"

#define	HEUR_DISPCHAR SCIP_HEURDISPCHAR_PROP

#define	HEUR_PRIORITY 2500

#define	HEUR_FREQ 0

#define	HEUR_FREQOFS 0

#define	HEUR_MAXDEPTH -1

#define	HEUR_TIMING SCIP_HEURTIMING_BEFORENODE

#define	HEUR_USESSUBSCIP TRUE

#define	DEFAULT_MAXNODES 5000LL

#define	DEFAULT_MININTFIXINGRATE 0.65

#define	DEFAULT_MINMIPFIXINGRATE 0.65

#define	DEFAULT_MINIMPROVE 0.01

#define	DEFAULT_MINNODES 500LL

#define	DEFAULT_NODESOFS 500LL

#define	DEFAULT_NODESQUOT 0.1

#define	DEFAULT_MAXPROPROUNDS 2

#define	DEFAULT_MAXBACKTRACKS 10

#define	DEFAULT_COPYCUTS TRUE

#define	DEFAULT_USELOCKFIXINGS FALSE

#define	DEFAULT_FEASVARIANT (VBOUNDVARIANT_BESTBOUND \| VBOUNDVARIANT_WORSTBOUND)

#define	DEFAULT_TIGHTENVARIANT (VBOUNDVARIANT_NOOBJ \| VBOUNDVARIANT_BESTBOUND \| VBOUNDVARIANT_WORSTBOUND)

Heuristic defines
The heuristic works on indices representing a bound of a variable. This index will be called bound index in the following. For a given active variable with problem index i (note that active variables have problem indices between 0 and nactivevariable - 1), the bound index of its lower bound is 2i, the bound index of its upper bound is 2i + 1. The other way around, a given bound index i corresponds to the variable with problem index i/2 (rounded down), and to the lower bound, if i is even, to the upper bound if i is odd. The following macros can be used to convert bound index into variable problem index and boundtype and vice versa.
#define	getLbIndex(idx) (2*(idx))

#define	getUbIndex(idx) (2*(idx)+1)

#define	getVarIndex(idx) ((idx)/2)

#define	getBoundtype(idx) (((idx) % 2 == 0) ? SCIP_BOUNDTYPE_LOWER : SCIP_BOUNDTYPE_UPPER)

#define	isIndexLowerbound(idx) ((idx) % 2 == 0)

#define	getOtherBoundIndex(idx) (((idx) % 2 == 0) ? (idx) + 1 : (idx) - 1)

static void	heurdataReset (SCIP_HEURDATA *heurdata)

static SCIP_RETCODE	dfs (SCIP scip, int startnode, SCIP_Shortbool visited, int dfsstack, int stacknextedge, int stacknextcliquevar, int cliqueexit, int dfsnodes, int ndfsnodes)

static SCIP_RETCODE	topologicalSort (SCIP scip, int vbvars, int *nvbvars)

static SCIP_RETCODE	initializeCandsLists (SCIP scip, SCIP_HEURDATA heurdata)

static SCIP_RETCODE	applyVboundsFixings (SCIP scip, SCIP_HEURDATA heurdata, SCIP_VAR *vars, int nvbvars, SCIP_Bool tighten, int obj, SCIP_Bool allobj1, SCIP_Bool allobj2, SCIP_Bool backtracked, SCIP_Bool *infeasible)

static SCIP_RETCODE	setupAndSolveSubscip (SCIP scip, SCIP subscip, SCIP_HEUR heur, SCIP_VAR vars, int nvars, SCIP_Longint nstallnodes, SCIP_Real lowerbound, int nprevars, SCIP_Bool wasfeas, SCIP_RESULT result)

static SCIP_RETCODE	applyVbounds (SCIP scip, SCIP_HEUR heur, SCIP_HEURDATA heurdata, SCIP_VAR vbvars, int nvbvars, SCIP_Bool tighten, int obj, SCIP_Bool skipobj1, SCIP_Bool skipobj2, SCIP_RESULT result)

static	SCIP_DECL_HEURCOPY (heurCopyVbounds)

static	SCIP_DECL_HEURFREE (heurFreeVbounds)

static	SCIP_DECL_HEUREXITSOL (heurExitsolVbounds)

static	SCIP_DECL_HEUREXEC (heurExecVbounds)

SCIP_RETCODE	SCIPincludeHeurVbounds (SCIP *scip)

Macro Definition Documentation

◆ VBOUNDVARIANT_NOOBJ

#define VBOUNDVARIANT_NOOBJ 0x001u

Definition at line 78 of file heur_vbounds.c.

◆ VBOUNDVARIANT_BESTBOUND

#define VBOUNDVARIANT_BESTBOUND 0x002u

Definition at line 79 of file heur_vbounds.c.

◆ VBOUNDVARIANT_WORSTBOUND

#define VBOUNDVARIANT_WORSTBOUND 0x004u

Definition at line 80 of file heur_vbounds.c.

◆ HEUR_NAME

#define HEUR_NAME "vbounds"

Definition at line 82 of file heur_vbounds.c.

Referenced by applyVbounds().

◆ HEUR_DESC

#define HEUR_DESC "LNS heuristic uses the variable lower and upper bounds to determine the search neighborhood"

Definition at line 83 of file heur_vbounds.c.

◆ HEUR_DISPCHAR

#define HEUR_DISPCHAR SCIP_HEURDISPCHAR_PROP

Definition at line 84 of file heur_vbounds.c.

◆ HEUR_PRIORITY

#define HEUR_PRIORITY 2500

Definition at line 85 of file heur_vbounds.c.

◆ HEUR_FREQ

#define HEUR_FREQ 0

Definition at line 86 of file heur_vbounds.c.

◆ HEUR_FREQOFS

#define HEUR_FREQOFS 0

Definition at line 87 of file heur_vbounds.c.

◆ HEUR_MAXDEPTH

#define HEUR_MAXDEPTH -1

Definition at line 88 of file heur_vbounds.c.

◆ HEUR_TIMING

#define HEUR_TIMING SCIP_HEURTIMING_BEFORENODE

Definition at line 89 of file heur_vbounds.c.

◆ HEUR_USESSUBSCIP

#define HEUR_USESSUBSCIP TRUE

does the heuristic use a secondary SCIP instance?

Definition at line 90 of file heur_vbounds.c.

◆ DEFAULT_MAXNODES

#define DEFAULT_MAXNODES 5000LL

maximum number of nodes to regard in the subproblem

Definition at line 92 of file heur_vbounds.c.

◆ DEFAULT_MININTFIXINGRATE

#define DEFAULT_MININTFIXINGRATE 0.65

minimum percentage of integer variables that have to be fixed

Definition at line 93 of file heur_vbounds.c.

◆ DEFAULT_MINMIPFIXINGRATE

#define DEFAULT_MINMIPFIXINGRATE 0.65

minimuskipobjm percentage of variables that have to be fixed within sub-SCIP (integer and continuous)

Definition at line 94 of file heur_vbounds.c.

◆ DEFAULT_MINIMPROVE

#define DEFAULT_MINIMPROVE 0.01

factor by which vbounds heuristic should at least improve the incumbent

Definition at line 97 of file heur_vbounds.c.

◆ DEFAULT_MINNODES

#define DEFAULT_MINNODES 500LL

minimum number of nodes to regard in the subproblem

Definition at line 100 of file heur_vbounds.c.

◆ DEFAULT_NODESOFS

#define DEFAULT_NODESOFS 500LL

number of nodes added to the contingent of the total nodes

Definition at line 101 of file heur_vbounds.c.

◆ DEFAULT_NODESQUOT

#define DEFAULT_NODESQUOT 0.1

subproblem nodes in relation to nodes of the original problem

Definition at line 102 of file heur_vbounds.c.

◆ DEFAULT_MAXPROPROUNDS

#define DEFAULT_MAXPROPROUNDS 2

maximum number of propagation rounds during probing

Definition at line 103 of file heur_vbounds.c.

◆ DEFAULT_MAXBACKTRACKS

#define DEFAULT_MAXBACKTRACKS 10

maximum number of backtracks during the fixing process

Definition at line 104 of file heur_vbounds.c.

◆ DEFAULT_COPYCUTS

#define DEFAULT_COPYCUTS TRUE

should all active cuts from the cutpool of the original scip be copied to constraints of the subscip?

Definition at line 105 of file heur_vbounds.c.

◆ DEFAULT_USELOCKFIXINGS

#define DEFAULT_USELOCKFIXINGS FALSE

should more variables be fixed based on variable locks if the fixing rate was not reached?

Definition at line 108 of file heur_vbounds.c.

◆ DEFAULT_FEASVARIANT

#define DEFAULT_FEASVARIANT (VBOUNDVARIANT_BESTBOUND | VBOUNDVARIANT_WORSTBOUND)

which variants of the vbounds heuristic that try to stay feasible should be called?

Definition at line 115 of file heur_vbounds.c.

◆ DEFAULT_TIGHTENVARIANT

#define DEFAULT_TIGHTENVARIANT (VBOUNDVARIANT_NOOBJ | VBOUNDVARIANT_BESTBOUND | VBOUNDVARIANT_WORSTBOUND)

which tightening variants of the vbounds heuristic should be called?

Definition at line 118 of file heur_vbounds.c.

◆ getLbIndex

#define getLbIndex ( idx ) (2*(idx))

Definition at line 165 of file heur_vbounds.c.

Referenced by dfs().

◆ getUbIndex

#define getUbIndex ( idx ) (2*(idx)+1)

Definition at line 166 of file heur_vbounds.c.

Referenced by dfs().

◆ getVarIndex

#define getVarIndex ( idx ) ((idx)/2)

Definition at line 167 of file heur_vbounds.c.

Referenced by dfs().

◆ getBoundtype

#define getBoundtype ( idx ) (((idx) % 2 == 0) ? SCIP_BOUNDTYPE_LOWER : SCIP_BOUNDTYPE_UPPER)

Definition at line 168 of file heur_vbounds.c.

◆ isIndexLowerbound

#define isIndexLowerbound ( idx ) ((idx) % 2 == 0)

Definition at line 169 of file heur_vbounds.c.

Referenced by dfs().

◆ getOtherBoundIndex

#define getOtherBoundIndex ( idx ) (((idx) % 2 == 0) ? (idx) + 1 : (idx) - 1)

Definition at line 170 of file heur_vbounds.c.

Referenced by dfs().

Function Documentation

◆ heurdataReset()

static void heurdataReset ( SCIP_HEURDATA * heurdata )

static

reset heuristic data structure

Parameters

heurdata structure containing heurdata

Definition at line 179 of file heur_vbounds.c.

◆ dfs()

static SCIP_RETCODE dfs	(	SCIP *	scip,
		int	startnode,
		SCIP_Shortbool *	visited,
		int *	dfsstack,
		int *	stacknextedge,
		int *	stacknextcliquevar,
		int *	cliqueexit,
		int *	dfsnodes,
		int *	ndfsnodes
	)

static

performs depth-first-search in the implicitly given directed graph from the given start index

Parameters

scip	SCIP data structure
startnode	node to start the depth-first-search
visited	array to store for each node, whether it was already visited
dfsstack	array of size number of nodes to store the stack; only needed for performance reasons
stacknextedge	array of size number of nodes to store the number of adjacent nodes already visited for each node on the stack; only needed for performance reasons
stacknextcliquevar	array of size number of nodes to store the number of variables already evaluated for the clique currently being evaluated
cliqueexit	exit node when entering a clique
dfsnodes	array of nodes that can be reached starting at startnode, in reverse dfs order
ndfsnodes	pointer to store number of nodes that can be reached starting at startnode

Definition at line 193 of file heur_vbounds.c.

References FALSE, getLbIndex, getOtherBoundIndex, getUbIndex, getVarIndex, isIndexLowerbound, MAX, NULL, SCIP_Bool, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPcliqueGetIndex(), SCIPcliqueGetNVars(), SCIPcliqueGetValues(), SCIPcliqueGetVars(), SCIPgetNVars(), SCIPgetVars(), SCIPisPositive(), SCIPvarGetCliques(), SCIPvarGetNCliques(), SCIPvarGetNVlbs(), SCIPvarGetNVubs(), SCIPvarGetProbindex(), SCIPvarGetType(), SCIPvarGetVlbCoefs(), SCIPvarGetVlbVars(), SCIPvarGetVubCoefs(), SCIPvarGetVubVars(), SCIPvarIsActive(), SCIPvarIsBinary(), topologicalSort(), and TRUE.

Referenced by topologicalSort().

◆ topologicalSort()

static SCIP_RETCODE topologicalSort	(	SCIP *	scip,
		int *	vbvars,
		int *	nvbvars
	)

static

sort the bounds of variables topologically

Parameters

scip	SCIP data structure
vbvars	array to store variable bounds in topological order
nvbvars	pointer to store number of variable bounds in the graph

Definition at line 422 of file heur_vbounds.c.

References dfs(), initializeCandsLists(), NULL, SCIP_CALL, SCIP_OKAY, SCIP_Shortbool, SCIPallocBufferArray, SCIPallocClearBufferArray, SCIPfreeBufferArray, SCIPgetNCliques(), and SCIPgetNVars().

Referenced by dfs().

◆ initializeCandsLists()

static SCIP_RETCODE initializeCandsLists	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata
	)

static

initialize candidate lists

Parameters

scip	original SCIP data structure
heurdata	structure containing heurdata

Definition at line 470 of file heur_vbounds.c.

Referenced by topologicalSort().

◆ applyVboundsFixings()

static SCIP_RETCODE applyVboundsFixings	(	SCIP *	scip,
		SCIP_HEURDATA *	heurdata,
		SCIP_VAR **	vars,
		int	nvbvars,
		SCIP_Bool	tighten,
		int	obj,
		SCIP_Bool *	allobj1,
		SCIP_Bool *	allobj2,
		SCIP_Bool *	backtracked,
		SCIP_Bool *	infeasible
	)

static

apply variable bound fixing during probing

Parameters

scip	original SCIP data structure
heurdata	structure containing heurdata
vars	variables to fix during probing
nvbvars	number of variables in the variable bound graph
tighten	should variables be fixed to cause other fixings?
obj	should the objective be taken into account?
allobj1	pointer to store whether all variables were fixed according to obj=1 scheme
allobj2	pointer to store whether all variables were fixed according to obj=2 scheme
backtracked	was backtracking performed at least once?
infeasible	pointer to store whether propagation detected infeasibility

Definition at line 558 of file heur_vbounds.c.

References bound, FALSE, NULL, SCIP_Bool, SCIP_BOUNDTYPE_UPPER, SCIP_CALL, SCIP_MAXTREEDEPTH, SCIP_OKAY, SCIP_Real, SCIP_VARTYPE_CONTINUOUS, SCIPbacktrackProbing(), SCIPchgVarLbProbing(), SCIPchgVarUbProbing(), SCIPdebugMessage, SCIPdebugMsg, SCIPfixVarProbing(), SCIPgetDepth(), SCIPgetNPseudoBranchCands(), SCIPgetProbingDepth(), SCIPisInfinity(), SCIPnewProbingNode(), SCIPpropagateProbing(), SCIPvarGetLbLocal(), SCIPvarGetName(), SCIPvarGetObj(), SCIPvarGetType(), SCIPvarGetUbLocal(), setupAndSolveSubscip(), and TRUE.

Referenced by applyVbounds().

◆ setupAndSolveSubscip()

static SCIP_RETCODE setupAndSolveSubscip	(	SCIP *	scip,
		SCIP *	subscip,
		SCIP_HEUR *	heur,
		SCIP_VAR **	vars,
		int	nvars,
		SCIP_Longint	nstallnodes,
		SCIP_Real	lowerbound,
		int *	nprevars,
		SCIP_Bool *	wasfeas,
		SCIP_RESULT *	result
	)

static

copy problem to sub-SCIP, solve it, and add solutions

Parameters

scip	original SCIP data structure
subscip	SCIP structure of the subproblem
heur	heuristic
vars	variables of the main SCIP
nvars	number of variables of the main SCIP
nstallnodes	stalling node limit for the sub-SCIP
lowerbound	lower bound of the main SCIP / current subproblem
nprevars	pointer to store the number of presolved variables
wasfeas	pointer to store if a feasible solution was found
result	pointer to store the result

Definition at line 739 of file heur_vbounds.c.

References applyVbounds(), FALSE, NULL, SCIP_CALL, SCIP_CALL_ABORT, SCIP_FOUNDSOL, SCIP_OKAY, SCIP_PARAMSETTING_FAST, SCIP_PARAMSETTING_OFF, SCIP_Real, SCIPallocBufferArray, SCIPblkmem(), SCIPcopyConsCompression(), SCIPcopyCuts(), SCIPcopyLimits(), SCIPdebugMsg, SCIPfindBranchrule(), SCIPfreeBufferArray, SCIPgetNConss(), SCIPgetNSols(), SCIPgetNVars(), SCIPgetSolvingTime(), SCIPgetStatus(), SCIPgetUpperbound(), SCIPhashmapCreate(), SCIPhashmapFree(), SCIPhashmapGetImage(), SCIPheurGetData(), SCIPisInfinity(), SCIPisParamFixed(), SCIPpresolve(), SCIPprintStatistics(), SCIPsetBoolParam(), SCIPsetIntParam(), SCIPsetLongintParam(), SCIPsetObjlimit(), SCIPsetPresolving(), SCIPsetSeparating(), SCIPsetSubscipsOff(), SCIPsolve(), SCIPsumepsilon(), SCIPtranslateSubSols(), and TRUE.

Referenced by applyVbounds(), and applyVboundsFixings().

◆ applyVbounds()

static SCIP_RETCODE applyVbounds	(	SCIP *	scip,
		SCIP_HEUR *	heur,
		SCIP_HEURDATA *	heurdata,
		SCIP_VAR **	vbvars,
		int	nvbvars,
		SCIP_Bool	tighten,
		int	obj,
		SCIP_Bool *	skipobj1,
		SCIP_Bool *	skipobj2,
		SCIP_RESULT *	result
	)

static

main procedure of the vbounds heuristic

Parameters

scip	original SCIP data structure
heur	heuristic
heurdata	heuristic data structure
vbvars	variables to fix during probing
nvbvars	number of variables to fix
tighten	should variables be fixed to cause other fixings?
obj	should the objective be taken into account?
skipobj1	pointer to store whether the run with obj=1 can be skipped, or NULL
skipobj2	pointer to store whether the run with obj=2 can be skipped, or NULL
result	pointer to store the result

Definition at line 900 of file heur_vbounds.c.

References applyVboundsFixings(), FALSE, HEUR_NAME, NULL, SCIP_Bool, SCIP_CALL, SCIP_DECL_HEURCOPY(), SCIP_DIDNOTFIND, SCIP_DIDNOTRUN, SCIP_FOUNDSOL, SCIP_Longint, SCIP_LPSOLSTAT_ERROR, SCIP_LPSOLSTAT_INFEASIBLE, SCIP_LPSOLSTAT_OBJLIMIT, SCIP_LPSOLSTAT_OPTIMAL, SCIP_MAXSTRLEN, SCIP_OKAY, SCIP_Real, SCIP_VERBLEVEL_FULL, SCIPapplyLockFixings(), SCIPcheckCopyLimits(), SCIPcheckSol(), SCIPclockGetTime(), SCIPconstructLP(), SCIPcreate(), SCIPcreateClock(), SCIPcreateSol(), SCIPcutoffNode(), SCIPdebugMsg, SCIPenableVarHistory(), SCIPendProbing(), SCIPflushLP(), SCIPfree(), SCIPfreeClock(), SCIPfreeSol(), SCIPgetCurrentNode(), SCIPgetLowerbound(), SCIPgetLPObjval(), SCIPgetLPSolstat(), SCIPgetNLPCols(), SCIPgetNLPIterations(), SCIPgetNNodes(), SCIPgetNPseudoBranchCands(), SCIPgetNUnfixedLPCols(), SCIPgetNVars(), SCIPgetSolOrigObj(), SCIPgetSolvingTime(), SCIPgetVarsData(), SCIPhasCurrentNodeLP(), SCIPheurGetName(), SCIPheurGetNBestSolsFound(), SCIPheurGetNCalls(), SCIPinProbing(), SCIPisLPConstructed(), SCIPisLPSolBasic(), SCIPisStopped(), SCIPlinkLPSol(), SCIPnodeGetNumber(), SCIProundSol(), SCIPsnprintfProbingStats(), SCIPsolveProbingLP(), SCIPstartClock(), SCIPstartProbing(), SCIPstatistic, SCIPstatisticMessage, SCIPstopClock(), SCIPtrySol(), SCIPverbMessage(), SCIPwarningMessage(), setupAndSolveSubscip(), and TRUE.

Referenced by setupAndSolveSubscip().

◆ SCIP_DECL_HEURCOPY()

static SCIP_DECL_HEURCOPY ( heurCopyVbounds )

static

copy method for primal heuristic plugins (called when SCIP copies plugins)

Definition at line 1219 of file heur_vbounds.c.

Referenced by applyVbounds().

◆ SCIP_DECL_HEURFREE()

static SCIP_DECL_HEURFREE ( heurFreeVbounds )

static

destructor of primal heuristic to free user data (called when SCIP is exiting)

Definition at line 1233 of file heur_vbounds.c.

◆ SCIP_DECL_HEUREXITSOL()

static SCIP_DECL_HEUREXITSOL ( heurExitsolVbounds )

static

solving process deinitialization method of primal heuristic (called before branch and bound process data is freed)

Definition at line 1249 of file heur_vbounds.c.

◆ SCIP_DECL_HEUREXEC()

static SCIP_DECL_HEUREXEC ( heurExecVbounds )

static

execution method of primal heuristic

Definition at line 1275 of file heur_vbounds.c.

SCIP

Detailed Description

Macros

Heuristic defines

Macro Definition Documentation

◆ VBOUNDVARIANT_NOOBJ

◆ VBOUNDVARIANT_BESTBOUND

◆ VBOUNDVARIANT_WORSTBOUND

◆ HEUR_NAME

◆ HEUR_DESC

◆ HEUR_DISPCHAR

◆ HEUR_PRIORITY

◆ HEUR_FREQ

◆ HEUR_FREQOFS

◆ HEUR_MAXDEPTH

◆ HEUR_TIMING

◆ HEUR_USESSUBSCIP

◆ DEFAULT_MAXNODES

◆ DEFAULT_MININTFIXINGRATE

◆ DEFAULT_MINMIPFIXINGRATE

◆ DEFAULT_MINIMPROVE

◆ DEFAULT_MINNODES

◆ DEFAULT_NODESOFS

◆ DEFAULT_NODESQUOT

◆ DEFAULT_MAXPROPROUNDS

◆ DEFAULT_MAXBACKTRACKS

◆ DEFAULT_COPYCUTS

◆ DEFAULT_USELOCKFIXINGS

◆ DEFAULT_FEASVARIANT

◆ DEFAULT_TIGHTENVARIANT

◆ getLbIndex

◆ getUbIndex

◆ getVarIndex

◆ getBoundtype

◆ isIndexLowerbound

◆ getOtherBoundIndex

Function Documentation

◆ heurdataReset()

◆ dfs()

◆ topologicalSort()

◆ initializeCandsLists()

◆ applyVboundsFixings()

◆ setupAndSolveSubscip()

◆ applyVbounds()

◆ SCIP_DECL_HEURCOPY()

◆ SCIP_DECL_HEURFREE()

◆ SCIP_DECL_HEUREXITSOL()

◆ SCIP_DECL_HEUREXEC()