Approximation algorithms for the node coloring problem in graphs. More...

#include <ogdf/graphalg/NodeColoringJohnson.h>

Inheritance diagram for ogdf::NodeColoringJohnson:

Public Types
enum	MinDegreeProcedure { MinDegreeProcedure::smallestIndex, MinDegreeProcedure::minDegreeOriginal, MinDegreeProcedure::maxDegreeOriginal, MinDegreeProcedure::minDegreeSubgraph, MinDegreeProcedure::maxDegreeSubgraph }
	Declares procedure to find the minimum degree nodes. More...

Public Types inherited from ogdf::NodeColoringModule
using	NodeColor = unsigned int
	Data type of the node colors. More...

enum	RamseyProcedure { RamseyProcedure::smallestIndex, RamseyProcedure::smallestDegree, RamseyProcedure::largestDegree, RamseyProcedure::extremalDegree }
	Declares the procedure of finding nodes in Ramsey's algorithm. More...

enum	SearchProcedure { SearchProcedure::linearSearch, SearchProcedure::binarySearch, SearchProcedure::wigdersonSearch }
	Declares the search procedures. More...

Public Member Functions
	NodeColoringJohnson ()
	The constructor. More...

virtual NodeColor	call (const Graph &graph, NodeArray< NodeColor > &colors, NodeColor start=0) override
	The actual algorithm call. More...

void	setMinDegreeProcedure (MinDegreeProcedure minDegreeProcedure)
	Sets the procedure of finding minimum degree nodes. More...

Public Member Functions inherited from ogdf::NodeColoringModule
	NodeColoringModule ()
	Default constructor. More...

virtual	~NodeColoringModule ()
	Destructor. More...

virtual bool	checkColoring (const Graph &graph, const NodeArray< NodeColor > &colors) const
	Checks if the given node coloring is valid. More...

virtual void	preprocessGraph (Graph &graph) const
	Preprocesses a graph so that a coloring algorithm can be applied. More...

Private Attributes
MinDegreeProcedure	m_minDegreeProcedure

Additional Inherited Members
Protected Member Functions inherited from ogdf::NodeColoringModule
template<class CONTAINER >
bool	checkIndependentSet (const Graph &graph, const CONTAINER &nodes) const
	Checks if subgraph induced by the given nodes forms an independent set. More...

virtual void	cliqueRemoval (const Graph &graph, List< node > &independentSet) const
	Applies the clique removal algorithm for finding a large independent set in a given graph. More...

virtual void	createBuckets (const Graph &graph, int size, Array< Array< node >> &buckets) const
	Creates a partitioning of the node set into buckets of a given size. More...

virtual int	getMaximumDegreeNode (const Graph &graph, node &maxDegreeNode) const
	Searches for a maximum degree node in the graph. More...

virtual int	getMaximumDegreeNodes (const Graph &graph, List< node > &maxDegreeNodes) const
	Searches for all nodes with maximum degree in the graph. More...

virtual NodeColor	getMaximumNodeColor (NodeArray< NodeColor > &colors)
	Calculates the maximum node color index used in a certain node coloring. More...

virtual int	getMinimumDegreeNode (const Graph &graph, node &minDegreeNode) const
	Searches for a minimum degree node in the graph. More...

virtual int	getMinimumDegreeNodes (const Graph &graph, List< node > &minDegreeNodes) const
	Searches for all nodes with minimum degree in the graph. More...

int	getNeighborDegrees (const node &v) const
	Calculates the sum of neighbor nodes degrees for a given node v. More...

template<class LISTITERATOR >
void	getNeighbors (const Graph &graph, LISTITERATOR nodes, List< node > &neighbors) const
	Calculates the set of neighbors Y for a given set of nodes X. More...

template<class LISTITERATOR >
void	getNeighborsComplement (const Graph &graph, LISTITERATOR nodes, List< node > &complementNeighbors) const
	Calculates the set of complement neighbors Y for a given set of nodes X. More...

template<class LISTITERATOR >
void	mergeNodeLists (const Graph &graph, LISTITERATOR firstList, LISTITERATOR secondList, List< node > &mergedList) const
	Merges two lists of nodes and deletes the duplicates. More...

virtual void	ramseyAlgorithm (const Graph &graph, List< node > &clique, List< node > &independentSet) const
	Performs the Ramsey algorithm for finding heuristically large cliques and independents sets in a graph. More...

virtual void	reverseNodeTable (const Graph &graphOrig, const Graph &graphNew, const NodeArray< node > &orig2New, NodeArray< node > &new2Orig) const
	Reverses the mapping between the nodes sets of a graph and a subgraph. More...

int	searchBinary (SearchWrapper *searchWrapper, int start, int end) const
	Performs a binary search in a specified range with a given oracle. More...

int	searchLinear (SearchWrapper *searchWrapper, int start, int end) const
	Performs a linear search in a specified range with a given oracle. More...

int	searchWigderson (SearchWrapper *searchWrapper) const
	Performs a the search procedure specified by Wigderson. More...

Protected Attributes inherited from ogdf::NodeColoringModule
RamseyProcedure	m_ramseyProcedure
	The RamseyProcedure to be used to select nodes. More...

Detailed Description

Approximation algorithms for the node coloring problem in graphs.

This class implements the approximation given by Johnson which tries to find heuristically large independent sets one other the other.

Definition at line 45 of file NodeColoringJohnson.h.

Member Enumeration Documentation

◆ MinDegreeProcedure

enum ogdf::NodeColoringJohnson::MinDegreeProcedure

strong

Declares procedure to find the minimum degree nodes.

Enumerator
smallestIndex	Use the node with the smallest index.
minDegreeOriginal	Use the node which has the smallest degree in the original graph.
maxDegreeOriginal	Use the node which has the largest degree in the original graph.
minDegreeSubgraph	Use the node which has the smallest degree in the current subgraph.
maxDegreeSubgraph	Use the node which has the largest degree in the current subgraph.

Definition at line 50 of file NodeColoringJohnson.h.

Constructor & Destructor Documentation

◆ NodeColoringJohnson()

ogdf::NodeColoringJohnson::NodeColoringJohnson ( )

inline

The constructor.

Initializes the procedure of finding minimum degree nodes with the smallest index.

Definition at line 62 of file NodeColoringJohnson.h.

Member Function Documentation

◆ call()

virtual NodeColor ogdf::NodeColoringJohnson::call	(	const Graph &	graph,
		NodeArray< NodeColor > &	colors,
		NodeColor	start = `0`
	)

overridevirtual

The actual algorithm call.

Parameters

graph	The graph for which the node coloring will be calculated.
colors	The resulting node coloring.
start	The first color index which will be used.

Returns: The number of colors used by the node coloring.

Implements ogdf::NodeColoringModule.

◆ setMinDegreeProcedure()

void ogdf::NodeColoringJohnson::setMinDegreeProcedure ( MinDegreeProcedure minDegreeProcedure )

inline

Sets the procedure of finding minimum degree nodes.

Parameters

minDegreeProcedure The desired minimum degree finding procedure

Definition at line 68 of file NodeColoringJohnson.h.

Member Data Documentation

◆ m_minDegreeProcedure

MinDegreeProcedure ogdf::NodeColoringJohnson::m_minDegreeProcedure

private

Definition at line 76 of file NodeColoringJohnson.h.

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

include/ogdf/graphalg/NodeColoringJohnson.h

OpenGraph DrawingFramework

Public Types

Public Member Functions

Private Attributes

Additional Inherited Members