structure
Class GraphListDirected

java.lang.Object
  structure.AbstractStructure
      structure.GraphList
          structure.GraphListDirected

All Implemented Interfaces:

Graph, Structure

public class GraphListDirected
extends GraphList

A class implementing a directed, adjacency-list based graph.

See Also:

GraphList, GraphListUndirected, GraphMatrixDirected

Field Summary

Fields inherited from class structure.GraphList

dict, directed

Constructor Summary

GraphListDirected()
Construct a directed, adjacency-list based graph.

Method Summary

void	addEdge(java.lang.Object vLabel1, java.lang.Object vLabel2, java.lang.Object label) Add an edge between two vertices within the graph.
int	edgeCount() Determine the number of edges in graph.
java.lang.Object	remove(java.lang.Object label) Remove a vertex from the graph.
java.lang.Object	removeEdge(java.lang.Object vLabel1, java.lang.Object vLabel2) Remove possible edge between vertices labeled vLabel1 and vLabel2.
java.lang.String	toString() Construct a string representation of graph.

Methods inherited from class structure.GraphList

add, clear, contains, containsEdge, degree, edges, get, getEdge, isDirected, isEmpty, isVisited, isVisitedEdge, iterator, neighbors, reset, size, visit, visitEdge

Methods inherited from class structure.AbstractStructure

elements, hashCode, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface structure.Structure

elements, values

Constructor Detail

GraphListDirected

public GraphListDirected()

Construct a directed, adjacency-list based graph.

Postcondition:

constructs an directed graph

Method Detail

addEdge

public void addEdge(java.lang.Object vLabel1,
                    java.lang.Object vLabel2,
                    java.lang.Object label)

Add an edge between two vertices within the graph. Edge is directed. Duplicate edges are silently replaced. Labels on edges may be null.

Specified by:

addEdge in interface Graph

Specified by:

addEdge in class GraphList

Parameters:

vLabel1 - Source vertex.

vLabel2 - Destination vertex.

label - Label associated with the edge.

Precondition:

vLabel1 and vLabel2 are labels of existing vertices, v1 & v2

Postcondition:

an edge is inserted between v1 and v2; if edge is new, it is labeled with label (can be null)

remove

public java.lang.Object remove(java.lang.Object label)

Remove a vertex from the graph. Associated edges are also removed. Non-vertices are silently ignored.

Specified by:

remove in interface Graph

Specified by:

remove in interface Structure

Specified by:

remove in class GraphList

Parameters:

label - The label of the vertex within the graph.

Returns:

The label associated with the vertex.

Precondition:

label is non-null vertex label

Postcondition:

vertex with "equals" label is removed, if found

removeEdge

public java.lang.Object removeEdge(java.lang.Object vLabel1,
                                   java.lang.Object vLabel2)

Remove possible edge between vertices labeled vLabel1 and vLabel2. vLabel1 is the source.

Specified by:

removeEdge in interface Graph

Specified by:

removeEdge in class GraphList

Parameters:

vLabel1 - Source vertex.

vLabel2 - Destination vertex.

Returns:

The label associated with the edge removed.

Precondition:

vLabel1 and vLabel2 are labels of existing vertices

Postcondition:

edge is removed, its label is returned

edgeCount

public int edgeCount()

Determine the number of edges in graph.

Specified by:

edgeCount in interface Graph

Specified by:

edgeCount in class GraphList

Returns:

Number of edges in graph.

Postcondition:

returns the number of edges in graph

toString

public java.lang.String toString()

Construct a string representation of graph.

Overrides:

toString in class java.lang.Object

Returns:

String representing graph.

Postcondition:

returns string representation of graph