Computes planar separators using the Dual of the graph. More...

#include <ogdf/graphalg/SeparatorDual.h>

Inheritance diagram for ogdf::SeparatorDual:

Public Member Functions
	SeparatorDual (bool useTriangulatingBFS=false, unsigned int treeHeightIt=0)
	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...

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

Public Member Functions inherited from ogdf::SeparatorLiptonTarjan
	SeparatorLiptonTarjan (bool useTriangulatingBFS=false, unsigned int treeHeightIt=0)
	Constructor. 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
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 void	makeTree () override
	Creates the BFS tree used by the algorithm. More...

Protected Member Functions inherited from ogdf::SeparatorLiptonTarjan
edge	chooseEdge () const
	Chooses the initial edge for the very first cycle. More...

void	fillLists (List< node > &separator, List< node > &first, List< node > &second) const
	Fills the lists with the cycle / inside / outside once the cycle is ready. 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
unsigned int	treeHeightIterations

bool	useTriBFS

Protected Attributes inherited from ogdf::SeparatorLiptonTarjan
std::shared_ptr< BFSTreeClassical >	tree

unsigned int	treeHeightIterations

bool	useTriBFS

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 the Dual of the graph.

Computes planar separators using the dual of the graph as presented in the textbook "The Design and Analysis of Algorithms" by D. Kozen, Springer, 1992.

Definition at line 52 of file SeparatorDual.h.

Constructor & Destructor Documentation

◆ SeparatorDual()

ogdf::SeparatorDual::SeparatorDual	(	bool	useTriangulatingBFS = `false`,
		unsigned int	treeHeightIt = `0`
	)

inline

Constructor.

Parameters

useTriangulatingBFS	whether to use triangulating BFS for the second phase or not
treeHeightIt	how many iterations of tree height maximization to perform in the first phase

Definition at line 60 of file SeparatorDual.h.

Member Function Documentation

◆ doSeparate()

virtual bool ogdf::SeparatorDual::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

Reimplemented from ogdf::SeparatorLiptonTarjan.

◆ getMaxSeparatorSize()

virtual double ogdf::SeparatorDual::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

Reimplemented from ogdf::SeparatorLiptonTarjan.

Definition at line 75 of file SeparatorDual.h.

◆ getSpecificName()

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

inlineoverridevirtual

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

Reimplemented from ogdf::SeparatorLiptonTarjan.

Definition at line 63 of file SeparatorDual.h.

◆ makeTree()

virtual void ogdf::SeparatorDual::makeTree ( )

overrideprotectedvirtual

Creates the BFS tree used by the algorithm.

Reimplemented from ogdf::SeparatorLiptonTarjan.

Member Data Documentation

◆ treeHeightIterations

unsigned int ogdf::SeparatorDual::treeHeightIterations

protected

Definition at line 84 of file SeparatorDual.h.

◆ useTriBFS

bool ogdf::SeparatorDual::useTriBFS

protected

Definition at line 83 of file SeparatorDual.h.

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

include/ogdf/graphalg/SeparatorDual.h

OpenGraph DrawingFramework

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SeparatorDual()

Member Function Documentation

◆ doSeparate()

◆ getMaxSeparatorSize()

◆ getSpecificName()

◆ makeTree()

Member Data Documentation

◆ treeHeightIterations

◆ useTriBFS

Open
Graph Drawing
Framework