edu.gwu.algtest
Class GraphEdge

java.lang.Object
  |
  +--edu.gwu.algtest.GraphEdge
public class GraphEdge
extends java.lang.Object

A GraphEdge instance is used to store a single edge, directed or undirected. The information stored are the two vertices on either side of the edge, and the edge weight (if any). A directed edge has a start-vertex and an end-vertex, and so, using the variables below make sense. What about an undirected edge? Since GraphEdge instances are used in adjacency-lists, observe that the undirected edge (3, 2) is stored in the vertex list for vertex 3 and the vertex list for vertex 2. In the vertex-list for vertex 3, we would use 3 as the startVertex and 2 as the endVertex. Likewise, in the the vertex list for vertex 2, we will use 2 as the startVertex and 3 as the endVertex. Thus, the variables are suitable for undirected graph edges as well. NOTE: the equals method checks both vertices, but not the weight.

Field Summary
 int endVertex
          The end vertex of the edge.
 int startVertex
          The start vertex of the edge.
 double weight
          Edge weight (default value: 1)
 
Constructor Summary
GraphEdge(int s, int e, double w)
          Constructor that takes all fields.
 
Method Summary
 boolean equals(java.lang.Object obj)
          equals will compare two graph edges to see it they represent the same edge: they are equal if the startVertex of each are identical and the endVertex of each are identical.
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

startVertex

public int startVertex
The start vertex of the edge.

endVertex

public int endVertex
The end vertex of the edge.

weight

public double weight
Edge weight (default value: 1)
Constructor Detail

GraphEdge

public GraphEdge(int s,
                 int e,
                 double w)
Constructor that takes all fields.
Parameters:
s - an int value
e - an int value
w - a double value
Method Detail

equals

public boolean equals(java.lang.Object obj)
equals will compare two graph edges to see it they represent the same edge: they are equal if the startVertex of each are identical and the endVertex of each are identical. The weight is ignored.
Overrides:
equals in class java.lang.Object
Parameters:
obj - an Object value
Returns:
a boolean value

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object