de.topobyte.adt.graph

Class Graph<T>

java.lang.Object

de.topobyte.adt.graph.Graph<T>

Type Parameters:

T - the type of node elements.

Direct Known Subclasses:

UndirectedGraph

public class Graph<T>
extends Object

A class to represent an unweighted directed graph.

Constructor Summary

Constructors

Constructor and Description
Graph()

Method Summary

Modifier and Type	Method and Description
void	addEdge(T a, T b) Add this edge to the graph.
void	addNode(T node) Add a node to the graph.
void	addNodes(Set<T> nodesToAdd) Add all these nodes to the graph.
int	degreeIn(T node) Get the number of incoming edges.
int	degreeOut(T node) Get the number of outgoing edges.
Set<T>	getEdgesIn(T node) Get all incoming edges (the nodes that can be reached via these edges).
Set<T>	getEdgesOut(T node) Get all outgoing edges (the nodes that can be reached via these edges).
Collection<T>	getNodes() Return the nodes of this graph.
Set<Set<T>>	getPartition() Get a partition of the graph.
void	removeAllNodes(Collection<T> toRemove) Remove a collection of nodes from the graph.
void	removeEdge(T a, T b) Remove this edge from graph.
void	removeNode(T node) Remove a node from the graph.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Graph

public Graph()

Method Detail

addNode

public void addNode(T node)

Add a node to the graph.

Parameters:

node - the node to add.

removeNode

public void removeNode(T node)

Remove a node from the graph.

Parameters:

node - the node to remove.

removeAllNodes

public void removeAllNodes(Collection<T> toRemove)

Remove a collection of nodes from the graph.

Parameters:

toRemove - the nodes to remove.

addNodes

public void addNodes(Set<T> nodesToAdd)

Add all these nodes to the graph.

Parameters:

nodesToAdd - a set of nodes to add.

addEdge

public void addEdge(T a,
                    T b)

Add this edge to the graph.

Parameters:

a - a node.

b - another node.

removeEdge

public void removeEdge(T a,
                       T b)

Remove this edge from graph.

Parameters:

a - a node.

b - another node.

getNodes

public Collection<T> getNodes()

Return the nodes of this graph.

Returns:

the set of nodes.

getEdgesOut

public Set<T> getEdgesOut(T node)

Get all outgoing edges (the nodes that can be reached via these edges).

Parameters:

node - the node whose edges to get.

Returns:

a set of reachable nodes.

getEdgesIn

public Set<T> getEdgesIn(T node)

Get all incoming edges (the nodes that can be reached via these edges).

Parameters:

node - the node whose incoming edges to get.

Returns:

a set of nodes that can reach this one.

degreeIn

public int degreeIn(T node)

Get the number of incoming edges.

Parameters:

node - the node.

Returns:

the number of incoming edges.

degreeOut

public int degreeOut(T node)

Get the number of outgoing edges.

Parameters:

node - the node.

Returns:

the number of outgoing edges.

getPartition

public Set<Set<T>> getPartition()

Get a partition of the graph. Each subset consist of a set of nodes that are connected. This currently expects the graph to be undirected.

Returns:

a partition of the graph.