com.whitestein.lsps.common.graph

Class DirectedGraph<V>

java.lang.Object

com.whitestein.lsps.common.graph.DirectedGraph<V>

Type Parameters:

V - type of vertex

public class DirectedGraph<V>
extends Object

Simple directed graph that allows loops.

Graph uses LinkedHashSet to preserve the order of vertices and edges.

Author:

rba

Constructor Summary

Constructors

Constructor and Description
DirectedGraph() Creates new instance of DirectedGraph with no vertices and edges.
DirectedGraph(Collection<? extends V> vertices) Creates new instance of DirectedGraph with given vertices and no edges.
DirectedGraph(Collection<? extends V> vertices, Collection<Edge<V>> edges) Creates new instance of DirectedGraph with given vertices and edges.
DirectedGraph(DirectedGraph<V> graph) Creates new instance of DirectedGraph as a copy of given graph.

Method Summary

Modifier and Type	Method and Description
void	addEdge(Edge<V> edge) Adds given edge to this graph.
void	addEdge(V source, V target) Creates and adds an edge to this graph.
void	addEdges(Collection<Edge<V>> edges) Adds a collection of edges to this graph.
void	addVertex(V vertex) Adds given vertex to this graph.
boolean	containsEdge(Edge<V> edge) Returns true if this graph contains given edge.
boolean	containsVertex(V vertex) Returns true if this graph contains given vertex.
boolean	equals(Object obj) Returns true if obj is DirectedGraph and has equal set of vertices and edges.
int	getDegree(V vertex) Returns sum of in and out degree of given vertex.
int	getEdgeCount() Returns count of edges.
Set<Edge<V>>	getEdges() Returns unmodifiable set of edges backed by this graph.
Set<Edge<V>>	getEdgesConnectedTo(V vertex) Returns edges with given vertex as source of target.
Set<Edge<V>>	getEdgesFrom(V vertex) Returns unmodifiable set of edges with given vertex as source backed by this graph.
Set<Edge<V>>	getEdgesTo(V vertex) Returns unmodifiable set of edges with given vertex as target backed by this graph.
int	getInDegree(V vertex) Returns in degree of given vertex.
int	getOutDegree(V vertex) Returns out degree of given vertex.
int	getVertexCount() Returns count of vertices.
Set<V>	getVertices() Returns unmodifiable set of vertices backed by this graph.
int	hashCode()
void	removeEdge(Edge<V> edge) Removes given edge from this graph.
void	removeEdges(Collection<Edge<V>> edges) Removes all given edges from this graph.
void	removeVertex(V vertex) Removes given vertex from this graph and all its edges.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

DirectedGraph

public DirectedGraph()

Creates new instance of DirectedGraph with no vertices and edges.

DirectedGraph

public DirectedGraph(Collection<? extends V> vertices)

Creates new instance of DirectedGraph with given vertices and no edges.

Parameters:

vertices - vertex collection

DirectedGraph

public DirectedGraph(DirectedGraph<V> graph)

Creates new instance of DirectedGraph as a copy of given graph.

Parameters:

graph - graph to copy

DirectedGraph

public DirectedGraph(Collection<? extends V> vertices,
                     Collection<Edge<V>> edges)

Creates new instance of DirectedGraph with given vertices and edges.

Parameters:

vertices - vertex collection

edges - edge collection

Method Detail

addVertex

public final void addVertex(V vertex)

Adds given vertex to this graph.

Parameters:

vertex - vertex to add

Throws:

NullPointerException - if vertex is null

removeVertex

public final void removeVertex(V vertex)

Removes given vertex from this graph and all its edges.

Parameters:

vertex - vertex to remove

containsVertex

public final boolean containsVertex(V vertex)

Returns true if this graph contains given vertex.

Parameters:

vertex - vertex

Returns:

true if this graph contains given vertex

addEdge

public final void addEdge(Edge<V> edge)

Adds given edge to this graph.

Parameters:

edge - edge to add

Throws:

NullPointerException - if edge is null

IllegalArgumentException - if edge connects not existing vertices

addEdges

public final void addEdges(Collection<Edge<V>> edges)

Adds a collection of edges to this graph.

Parameters:

edges -

addEdge

public final void addEdge(V source,
                          V target)

Creates and adds an edge to this graph.

Parameters:

source - a source vertex

target - a target vertex

Throws:

NullPointerException - if edge is null

IllegalArgumentException - if edge connects not existing vertices

removeEdge

public final void removeEdge(Edge<V> edge)

Removes given edge from this graph.

Parameters:

edge - edge to remove

removeEdges

public final void removeEdges(Collection<Edge<V>> edges)

Removes all given edges from this graph.

Parameters:

edges -

containsEdge

public final boolean containsEdge(Edge<V> edge)

Returns true if this graph contains given edge.

Parameters:

edge - edge

Returns:

true if this graph contains given edge

getEdgesFrom

public final Set<Edge<V>> getEdgesFrom(V vertex)

Returns unmodifiable set of edges with given vertex as source backed by this graph.

Parameters:

vertex - source vertex

Returns:

set of edges

getEdgesTo

public final Set<Edge<V>> getEdgesTo(V vertex)

Returns unmodifiable set of edges with given vertex as target backed by this graph.

Parameters:

vertex - target vertex

Returns:

set of edges

getEdgesConnectedTo

public final Set<Edge<V>> getEdgesConnectedTo(V vertex)

Returns edges with given vertex as source of target.

Parameters:

vertex - vertex

Returns:

set of edges

getOutDegree

public final int getOutDegree(V vertex)

Returns out degree of given vertex.

Parameters:

vertex -

Returns:

out degree of given vertex

getInDegree

public final int getInDegree(V vertex)

Returns in degree of given vertex.

Parameters:

vertex -

Returns:

in degree of given vertex

getDegree

public final int getDegree(V vertex)

Returns sum of in and out degree of given vertex.

Parameters:

vertex -

Returns:

sum of in and out degree of given vertex

getVertices

public final Set<V> getVertices()

Returns unmodifiable set of vertices backed by this graph.

Returns:

set of vertices of this graph

getEdges

public final Set<Edge<V>> getEdges()

Returns unmodifiable set of edges backed by this graph.

Returns:

set of edges of this graph

getVertexCount

public final int getVertexCount()

Returns count of vertices.

Returns:

count of vertices

getEdgeCount

public final int getEdgeCount()

Returns count of edges.

Returns:

count of edges

hashCode

public int hashCode()

Overrides:

hashCode in class Object

See Also:

Object.hashCode()

equals

public boolean equals(Object obj)

Returns true if obj is DirectedGraph and has equal set of vertices and edges.

Overrides:

equals in class Object

See Also:

Object.equals(java.lang.Object)

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()