structure
Class Vertex

java.lang.Object
  |
  +--structure.Vertex

Direct Known Subclasses:

GraphListVertex, GraphMatrixVertex

class Vertex

extends Object

A private implementation of a vertex for use in graphs. A vertex is capable of holding a label and has a flag that can be set to mark it as visited.

Typical Usage:

     Vertex v = new Vertex(someLabel);
     //...several graph related operations occur
     if(!v.isVisited()){
         Object label = v.label();
         v.visit();
     }
 

See Also:

GraphListVertex, GraphMatrixVertex

Field Summary

protected Object	label A label associated with vertex.
protected boolean	visited Whether or not a vertex has been visited.

Constructor Summary

Vertex(Object label)
Construct a vertex with an associated label.

Method Summary

boolean	equals(Object o) Returns true iff the labels of two vertices are equal.
int	hashCode() Return a hashcode associated with the vertex.
boolean	isVisited() Determine if the vertex has been visited.
Object	label() Fetch the label associated with vertex.
void	reset() Clears the visited flag.
String	toString() Construct a string representing vertex.
boolean	visit() Test and set the visited flag.

Methods inherited from class java.lang.Object

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

Field Detail

label

protected Object label

A label associated with vertex.

visited

protected boolean visited

Whether or not a vertex has been visited.

Constructor Detail

Vertex

public Vertex(Object label)

Construct a vertex with an associated label.

Parameters:

label - A label to be associated with vertex.

Method Detail

label

public Object label()

Fetch the label associated with vertex.

Postcondition:

returns user label associated w/vertex

Returns:

The label associated with vertex.

visit

public boolean visit()

Test and set the visited flag.

Postcondition:

returns, then marks vertex as being visited

Returns:

The value of the flag before marking

isVisited

public boolean isVisited()

Determine if the vertex has been visited.

Postcondition:

returns true iff vertex has been visited

Returns:

True iff the vertex has been visited.

reset

public void reset()

Clears the visited flag.

Postcondition:

marks vertex unvisited

equals

public boolean equals(Object o)

Returns true iff the labels of two vertices are equal.

Overrides:

equals in class Object

Parameters:

o - Another vertex.

Postcondition:

returns true iff vertex labels are equal

Returns:

True iff the vertex labels are equal.

hashCode

public int hashCode()

Return a hashcode associated with the vertex.

Overrides:

hashCode in class Object

Postcondition:

returns hash code for vertex

Returns:

An integer for use in hashing values into tables.

toString

public String toString()

Construct a string representing vertex.

Overrides:

toString in class Object

Postcondition:

returns string representation of vertex

Returns:

A string representing vertex.