Package com.jgalgo.alg

Interface CoresAlgo

public interface CoresAlgo

Cores computing algorithm.

Given a graph \(G=(V,E)\), a subgraph \(H\) induced by a subset of vertices \(W\) is a \(k\)-core or a core of order \(k\) if \(\forall v \in W : deg_H(v) \geq k\) and \(H\) is a maximal subgraph with this property. The core number of vertex is the highest order of a core that contains this vertex. The degree \(deg(v)\) can be: in-degree, out-degree, in-degree + out-degree, determining different types of cores. See EdgeDirection for more details.

Use newInstance() to get a default implementation of this interface. A builder obtained via newBuilder() may support different options to obtain different implementations.

Author:

Barak Ugav

See Also:

EdgeDirection

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	CoresAlgo.Builder	A builder for CoresAlgo objects.
static interface	CoresAlgo.IResult	The result of the cores computation for IntGraph.
static interface	CoresAlgo.Result<V,E>	The result of the cores computation.

Method Summary

Modifier and Type	Method	Description
default <V,E> CoresAlgo.Result<V,E>	computeCores(Graph<V,E> g)	Compute the cores of the graph with respect to both in and out degree of the vertices.
<V,E> CoresAlgo.Result<V,E>	computeCores(Graph<V,E> g, EdgeDirection degreeType)	Compute the cores of the graph with respect the given degree type.
static CoresAlgo.Builder	newBuilder()	Create a new builder for core algorithms.
static CoresAlgo	newInstance()	Create a new cores algorithm object.

Method Detail

computeCores

default <V,E> CoresAlgo.Result<V,E> computeCores(Graph<V,E> g)

Compute the cores of the graph with respect to both in and out degree of the vertices.

If g is IntGraph, the returned object is CoresAlgo.IResult.

For a detail description of the cores definition, see the interface documentation CoresAlgo.

Type Parameters:

V - the vertices type

E - the edges type

Parameters:

g - a graph

Returns:

the cores of the graph

computeCores

<V,E> CoresAlgo.Result<V,E> computeCores(Graph<V,E> g,
                                                     EdgeDirection degreeType)

Compute the cores of the graph with respect the given degree type.

Cores are defined with respect to either the out edges, in edges, or both. For undirected graphs the degree type is ignored.

If g is IntGraph, the returned object is CoresAlgo.IResult.

For a detail description of the cores definition, see the interface documentation CoresAlgo.

Type Parameters:

V - the vertices type

E - the edges type

Parameters:

g - a graph

degreeType - the degree type the cores are computed with respect to

Returns:

the cores of the graph

newInstance

static CoresAlgo newInstance()

Create a new cores algorithm object.

This is the recommended way to instantiate a new CoresAlgo object. The CoresAlgo.Builder might support different options to obtain different implementations.

Returns:

a default implementation of CoresAlgo

newBuilder

static CoresAlgo.Builder newBuilder()

Create a new builder for core algorithms.

Use newInstance() for a default implementation.

Returns:

a new builder for core algorithms