com.mhhe.clrs2e
Class ShortestPathInfo

java.lang.Object
  |
  +--com.mhhe.clrs2e.ShortestPathInfo

Direct Known Subclasses:

Dijkstra.DijkstraInfo

public class ShortestPathInfo

extends java.lang.Object

Class for information determined about a vertex during a shortest-path algorithm.

Field Summary

private double	d The current shortest-path estimate for this vertex.
private com.mhhe.clrs2e.Vertex	pi The current predecessor (parent) for this vertex.

Constructor Summary

ShortestPathInfo()
Initializes the shortest-path estimate to infinity and the predecessor to null.

Method Summary

double	getEstimate() Returns the shortest-path estimate.
com.mhhe.clrs2e.Vertex	getPredecessor() Returns the predecessor.
boolean	relax(com.mhhe.clrs2e.Vertex u, double du, double w) Relaxes an edge entering this vertex, say v, based on the Relax procedure on page 586 of Introduction to Algorithms, Second edition.
void	setEstimate(double newEstimate) Sets the shortest-path estimate.
void	setPredecessor(com.mhhe.clrs2e.Vertex v) Sets the predecessor.
java.lang.String	toString() Returns the String representation of this object.

Methods inherited from class java.lang.Object

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

Field Detail

d

private double d

The current shortest-path estimate for this vertex.

pi

private com.mhhe.clrs2e.Vertex pi

The current predecessor (parent) for this vertex.

Constructor Detail

ShortestPathInfo

public ShortestPathInfo()

Initializes the shortest-path estimate to infinity and the predecessor to null.

Method Detail

setEstimate

public void setEstimate(double newEstimate)

Sets the shortest-path estimate.

Parameters:

newEstimate - The new shortest-path estimate.

getEstimate

public double getEstimate()

Returns the shortest-path estimate.

setPredecessor

public void setPredecessor(com.mhhe.clrs2e.Vertex v)

Sets the predecessor.

Parameters:

v - The new predecessor.

getPredecessor

public com.mhhe.clrs2e.Vertex getPredecessor()

Returns the predecessor.

relax

public boolean relax(com.mhhe.clrs2e.Vertex u,
                     double du,
                     double w)

Relaxes an edge entering this vertex, say v, based on the Relax procedure on page 586 of Introduction to Algorithms, Second edition.

Parameters:

u - Vertex that the edge leaves.

du - u's shortest-path estimate.

w - The weight of the edge (u,v).

Returns:

true if the shortest-path estimate for v changes, false if the shortest-path estimate remains unchanged.

toString

public java.lang.String toString()

Returns the String representation of this object.

Overrides:

toString in class java.lang.Object