Class PQ

java.lang.Object
  |
  +--PQ

public class PQ

extends Object

A priority queue for GraphNodes. Priority is based on the cost field for a GraphNode.

See Also:

Queue

Constructor Summary

PQ(int maxN)
Constructs a PQ with a max maxN amount of GraphNodes.

Method Summary

void	PQdec(int key, double cost) Decrements the cost of a GraphNode in this PQ.
GraphNode	PQdel(GraphNode gn) Deletes specified GraphNode from the PQ.
GraphNode	PQdelmin() Deletes the minimum GraphNode from the PQ.
boolean	PQempty() Method that tells whether this PQ is empty
void	PQinc(int key, double cost) Increments the cost of a GraphNode in this PQ.
void	PQinsert(GraphNode gn) Inserts a GraphNode into this PQ

Methods inherited from class java.lang.Object

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

Constructor Detail

PQ

public PQ(int maxN)

Constructs a PQ with a max maxN amount of GraphNodes.

Parameters:

maxN - the maximum amount of GraphNodes for the PQ

Method Detail

PQempty

public boolean PQempty()

Method that tells whether this PQ is empty

Returns:

true if empty

PQinsert

public void PQinsert(GraphNode gn)

Inserts a GraphNode into this PQ

Parameters:

k - GraphNode to be inserted

See Also:

PQdel(GraphNode), PQdelmin()

PQdelmin

public GraphNode PQdelmin()

Deletes the minimum GraphNode from the PQ.

Returns:

the minimum GraphNode

See Also:

PQdel(GraphNode), PQinsert(GraphNode)

PQdel

public GraphNode PQdel(GraphNode gn)

Deletes specified GraphNode from the PQ.

Parameters:

gn - the GraphNode to be deleted

Returns:

the deleted GraphNode

See Also:

PQdelmin(), PQinsert(GraphNode)

PQdec

public void PQdec(int key,
                  double cost)

Decrements the cost of a GraphNode in this PQ.

Parameters:

key - the key of the GraphNode to be decremented

cost - the new cost for the GraphNode

PQinc

public void PQinc(int key,
                  double cost)

Increments the cost of a GraphNode in this PQ.

Parameters:

key - the key of the GraphNode to be incremented

cost - the new cost for the GraphNode