Computes planar separators using Fundamental Cycles. More...

#include <ogdf/graphalg/SeparatorLiptonTarjanFC.h>

Inheritance diagram for ogdf::SeparatorLiptonTarjanFC:

Public Member Functions
	SeparatorLiptonTarjanFC (bool useTriBFS=false)
	Constructor. More...

virtual double	getMaxSeparatorSize (int n) const override
	Provides the maximal separator size that this algorithm guarantees as a function of the number of nodes of the graph, or a negative value if the guarantee cannot be expressed through such a function. More...

Public Member Functions inherited from ogdf::PlanarSeparatorModule
	PlanarSeparatorModule ()

virtual	~PlanarSeparatorModule ()

void	addPostProcessor (Postprocessor &post)
	Adds a postprocessor to this separator, which will always be applied. More...

void	clearPostProcessors ()
	Deletes all appended postprocessors from this separator. More...

std::string	getExitPoint () const
	Returns the exitPoint, i.e. More...

virtual std::string	getName () const
	Returns the full name of this algorithm. More...

virtual bool	separate (const Graph &G, List< node > &separator, List< node > &first, List< node > &second, bool checkPreconditions=true) final
	Separates a planar graph. More...

virtual bool	separate (const Graph &G, NodeArray< short > &assignments, bool checkPreconditions=true) final
	Separates a planar graph. More...

void	setStartIndex (int index)

Protected Member Functions
edge	chooseEdge () const
	Randomly selects the initial edge for the first cycle. More...

virtual bool	doSeparate (const Graph &G, List< node > &separator, List< node > &first, List< node > &second) override
	Core of the specific separation algorithm - override this in inheriting classes. More...

virtual bool	findCycle (List< node > &separator, List< node > &first, List< node > &second)
	Finds a cycle that works as a separator. More...

virtual std::string	getSpecificName () const override
	Returns the unique name of the core algorithm, to be combined with postprocessors later. More...

Protected Member Functions inherited from ogdf::PlanarSeparatorModule
bool	cleanup (const Graph &G, List< node > &separator, List< node > &first, List< node > &second)
	Performs built-in post-processing: For small instances, it can happen that all nodes are assigned to the separator, while both components are empty, which can be fixed by moving half of the nodes to the first list. More...

node	getStartNode (const Graph &G) const
	Selects the starting node for the BFS. More...

bool	postProcess (const Graph &G, List< node > &separator, List< node > &first, List< node > &second)
	Apply all postprocessors. More...

virtual void	reset ()
	Reset everything to enable reuse of the module. More...

bool	separateComponents (GraphCopy &G, List< node > &separator, List< node > &first, List< node > &second, bool skip=false) const
	Checks if the graph consists of multiple connected components, takes necessary steps for fixing that, returns true if this already solved the graph, false if the core algorithm still needs to run. More...

bool	setup (const Graph &G, List< node > &separator, List< node > &first, List< node > &second, bool checkPreconditions=true)
	Performs some initial setup to ensure that all preconditions hold and takes trivial steps to separate the graph. More...

Protected Attributes
std::shared_ptr< ArrayBFSTree >	tree

bool	useTriangulatingBFS

Protected Attributes inherited from ogdf::PlanarSeparatorModule
std::string	exitPoint

std::shared_ptr< GraphCopy >	graph

std::vector< Postprocessor * >	postProcessors

int	startNodeIndex = -1

Detailed Description

Computes planar separators using Fundamental Cycles.

Computes planar separators using only the Fundamental Cycle Lemma (ie. the second half of Lipton Tarjan).

Definition at line 94 of file SeparatorLiptonTarjanFC.h.

Constructor & Destructor Documentation

◆ SeparatorLiptonTarjanFC()

ogdf::SeparatorLiptonTarjanFC::SeparatorLiptonTarjanFC ( bool useTriBFS = false )

inline

Constructor.

Parameters

useTriBFS whether to use triangulating BFS or not

Definition at line 101 of file SeparatorLiptonTarjanFC.h.

Member Function Documentation

◆ chooseEdge()

edge ogdf::SeparatorLiptonTarjanFC::chooseEdge ( ) const

protected

Randomly selects the initial edge for the first cycle.

Returns: the first edge

◆ doSeparate()

virtual bool ogdf::SeparatorLiptonTarjanFC::doSeparate	(	const Graph &	G,
		List< node > &	separator,
		List< node > &	first,
		List< node > &	second
	)

overrideprotectedvirtual

Core of the specific separation algorithm - override this in inheriting classes.

Precondition: G is planar, simple-undirected, connected and represents a Combinatorial Embedding = is planarly embedded already.

Parameters

G	the graph to be separated
separator	the separator nodes
first	the first component
second	the second component

Returns: true on success

Implements ogdf::PlanarSeparatorModule.

Reimplemented in ogdf::SeparatorDualFC.

◆ findCycle()

virtual bool ogdf::SeparatorLiptonTarjanFC::findCycle	(	List< node > &	separator,
		List< node > &	first,
		List< node > &	second
	)

protectedvirtual

Finds a cycle that works as a separator.

Parameters

separator	the separator nodes
first	the first component
second	the second component

Returns: true on success

Reimplemented in ogdf::SeparatorDualFC.

◆ getMaxSeparatorSize()

virtual double ogdf::SeparatorLiptonTarjanFC::getMaxSeparatorSize ( int n ) const

inlineoverridevirtual

Provides the maximal separator size that this algorithm guarantees as a function of the number of nodes of the graph, or a negative value if the guarantee cannot be expressed through such a function.

See e.g. SeparatorHarPeled or SeparatorDualFC for examples.

Parameters

n	the number of nodes of the graph

Returns: the maximal separator size

Implements ogdf::PlanarSeparatorModule.

Reimplemented in ogdf::SeparatorDualFC.

Definition at line 103 of file SeparatorLiptonTarjanFC.h.

◆ getSpecificName()

virtual std::string ogdf::SeparatorLiptonTarjanFC::getSpecificName ( ) const

inlineoverrideprotectedvirtual

Returns the unique name of the core algorithm, to be combined with postprocessors later.

Override this in inheriting methods.

Returns: the specific name as a string

Implements ogdf::PlanarSeparatorModule.

Reimplemented in ogdf::SeparatorDualFC.

Definition at line 112 of file SeparatorLiptonTarjanFC.h.

Member Data Documentation

◆ tree

std::shared_ptr<ArrayBFSTree> ogdf::SeparatorLiptonTarjanFC::tree

protected

Definition at line 110 of file SeparatorLiptonTarjanFC.h.

◆ useTriangulatingBFS

bool ogdf::SeparatorLiptonTarjanFC::useTriangulatingBFS

protected

Definition at line 109 of file SeparatorLiptonTarjanFC.h.

The documentation for this class was generated from the following file:

include/ogdf/graphalg/SeparatorLiptonTarjanFC.h

OpenGraph DrawingFramework

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SeparatorLiptonTarjanFC()

Member Function Documentation

◆ chooseEdge()

◆ doSeparate()

◆ findCycle()

◆ getMaxSeparatorSize()

◆ getSpecificName()

Member Data Documentation

◆ tree

◆ useTriangulatingBFS

Open
Graph Drawing
Framework