V
 the graph vertex typeE
 the graph edge typepublic class EdgeReversedGraph<V,E> extends GraphDelegator<V,E> implements Graph<V,E>
This class allows you to use a directed graph algorithm in reverse. For example, suppose you have
a directed graph representing a tree, with edges from parent to child, and you want to find all
of the parents of a node. To do this, simply create an edgereversed graph and pass that as input
to DepthFirstIterator
.
AsUndirectedGraph
,
Serialized FormDEFAULT_EDGE_WEIGHT
Constructor and Description 

EdgeReversedGraph(Graph<V,E> g)
Creates a new EdgeReversedGraph.

Modifier and Type  Method and Description 

E 
addEdge(V sourceVertex,
V targetVertex)
Creates a new edge in this graph, going from the source vertex to the target vertex, and
returns the created edge.

boolean 
addEdge(V sourceVertex,
V targetVertex,
E e)
Adds the specified edge to this graph, going from the source vertex to the target vertex.

Set<E> 
getAllEdges(V sourceVertex,
V targetVertex)
Returns a set of all edges connecting source vertex to target vertex if such vertices exist
in this graph.

E 
getEdge(V sourceVertex,
V targetVertex)
Returns an edge connecting source vertex to target vertex if such vertices and such edge
exist in this graph.

V 
getEdgeSource(E e)
Returns the source vertex of an edge.

V 
getEdgeTarget(E e)
Returns the target vertex of an edge.

Set<E> 
incomingEdgesOf(V vertex)
Returns a set of all edges incoming into the specified vertex.

int 
inDegreeOf(V vertex)
Returns the "in degree" of the specified vertex.

int 
outDegreeOf(V vertex)
Returns the "out degree" of the specified vertex.

Set<E> 
outgoingEdgesOf(V vertex)
Returns a set of all edges outgoing from the specified vertex.

E 
removeEdge(V sourceVertex,
V targetVertex)
Removes an edge going from source vertex to target vertex, if such vertices and such edge
exist in this graph.

String 
toString()
Returns a string of the parenthesized pair (V, E) representing this G=(V,E) graph.

addVertex, addVertex, containsEdge, containsVertex, degreeOf, edgeSet, edgesOf, getDelegate, getEdgeSupplier, getEdgeWeight, getType, getVertexSupplier, removeEdge, removeVertex, setEdgeWeight, vertexSet
assertVertexExist, containsEdge, equals, hashCode, removeAllEdges, removeAllEdges, removeAllEdges, removeAllVertices, toStringFromSets
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
addVertex, addVertex, containsEdge, containsEdge, containsVertex, degreeOf, edgeSet, edgesOf, getEdgeSupplier, getEdgeWeight, getType, getVertexSupplier, removeAllEdges, removeAllEdges, removeAllVertices, removeEdge, removeVertex, setEdgeWeight, setEdgeWeight, vertexSet
public E getEdge(V sourceVertex, V targetVertex)
GraphDelegator
null
. If any of the specified vertices is null
returns null
In undirected graphs, the returned edge may have its source and target vertices in the opposite order.
getEdge
in interface Graph<V,E>
getEdge
in class GraphDelegator<V,E>
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.Graph.getEdge(Object, Object)
public Set<E> getAllEdges(V sourceVertex, V targetVertex)
GraphDelegator
null
, returns
null
. If both vertices exist but no edges found, returns an empty set.
In undirected graphs, some of the returned edges may have their source and target vertices in the opposite order. In simple graphs the returned set is either singleton set or empty set.
getAllEdges
in interface Graph<V,E>
getAllEdges
in class GraphDelegator<V,E>
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.Graph.getAllEdges(Object, Object)
public E addEdge(V sourceVertex, V targetVertex)
GraphDelegator
null
.
The source and target vertices must already be contained in this graph. If they are not found
in graph IllegalArgumentException
is thrown.
This method creates the new edge e
using this graph's edge supplier (see
Graph.getEdgeSupplier()
). For the new edge to be added e
must not be
equal to any other edge the graph (even if the graph allows edgemultiplicity). More
formally, the graph must not contain any edge e2
such that
e2.equals(e)
. If such
e2
is found then the newly created edge e
is abandoned, the method leaves
this graph unchanged and returns null
.
If the underlying graph implementation's Graph.getEdgeSupplier()
returns
null
, then this method cannot create edges and throws an
UnsupportedOperationException
.
addEdge
in interface Graph<V,E>
addEdge
in class GraphDelegator<V,E>
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.
null
.Graph.addEdge(Object, Object)
public boolean addEdge(V sourceVertex, V targetVertex, E e)
GraphDelegator
e
, to this graph if this graph contains no edge e2
such that
e2.equals(e)
. If this graph already contains such an edge, the call leaves this
graph unchanged and returns false. Some graphs do not allow edgemultiplicity. In
such cases, if the graph already contains an edge from the specified source to the specified
target, than this method does not change the graph and returns
false
. If the edge was added to the graph, returns
true
.
The source and target vertices must already be contained in this graph. If they are not found in graph IllegalArgumentException is thrown.
addEdge
in interface Graph<V,E>
addEdge
in class GraphDelegator<V,E>
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.e
 edge to be added to this graph.Graph.addEdge(Object, Object, Object)
public int inDegreeOf(V vertex)
GraphDelegator
The "in degree" of a vertex in a directed graph is the number of inward directed edges from that vertex. See http://mathworld.wolfram.com/Indegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
inDegreeOf
in interface Graph<V,E>
inDegreeOf
in class GraphDelegator<V,E>
vertex
 vertex whose degree is to be calculated.Graph.inDegreeOf(Object)
public int outDegreeOf(V vertex)
GraphDelegator
The "out degree" of a vertex in a directed graph is the number of outward directed edges from that vertex. See http://mathworld.wolfram.com/Outdegree.html.
In the case of undirected graphs this method returns the number of edges touching the vertex. Edges with same source and target vertices (selfloops) are counted twice.
outDegreeOf
in interface Graph<V,E>
outDegreeOf
in class GraphDelegator<V,E>
vertex
 vertex whose degree is to be calculated.Graph.outDegreeOf(Object)
public Set<E> incomingEdgesOf(V vertex)
GraphDelegator
In the case of undirected graphs this method returns all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
incomingEdgesOf
in interface Graph<V,E>
incomingEdgesOf
in class GraphDelegator<V,E>
vertex
 the vertex for which the list of incoming edges to be returned.Graph.incomingEdgesOf(Object)
public Set<E> outgoingEdgesOf(V vertex)
GraphDelegator
In the case of undirected graphs this method returns all edges touching the vertex, thus, some of the returned edges may have their source and target vertices in the opposite order.
outgoingEdgesOf
in interface Graph<V,E>
outgoingEdgesOf
in class GraphDelegator<V,E>
vertex
 the vertex for which the list of outgoing edges to be returned.Graph.outgoingEdgesOf(Object)
public E removeEdge(V sourceVertex, V targetVertex)
GraphDelegator
null
otherwise.removeEdge
in interface Graph<V,E>
removeEdge
in class GraphDelegator<V,E>
sourceVertex
 source vertex of the edge.targetVertex
 target vertex of the edge.null
if no edge removed.Graph.removeEdge(Object, Object)
public V getEdgeSource(E e)
GraphDelegator
getEdgeSource
in interface Graph<V,E>
getEdgeSource
in class GraphDelegator<V,E>
e
 edge of interestGraph.getEdgeSource(Object)
public V getEdgeTarget(E e)
GraphDelegator
getEdgeTarget
in interface Graph<V,E>
getEdgeTarget
in class GraphDelegator<V,E>
e
 edge of interestGraph.getEdgeTarget(Object)
public String toString()
GraphDelegator
toString
in class GraphDelegator<V,E>
Object.toString()
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