brutil
Class PriorityQueueRadix

java.lang.Object
  |
  +--brutil.PriorityQueueRadix

public class PriorityQueueRadix

extends java.lang.Object

Constructor Summary

PriorityQueueRadix(int keySize)

Method Summary

boolean	decreaseKey(HandlePQ key, int newKey) Decreases the key value of the specified element.
HandlePQ	extractMin() Extracts the object with the smallest key value from the array Then the array is traversed to find the next smallest key
HandlePQ	insert(int key, java.lang.Object value) Appends a wrapper object with the value and its key to a list in the array The key is used as the radix postion of the array.
boolean	isEmpty() Returns true if the Priority Queue is empty
HandlePQ	min() Returns the smallest key value in the Priority Queue
java.lang.String	toString() Return a list of element stored inside the Priority Queue

Methods inherited from class java.lang.Object

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

Constructor Detail

PriorityQueueRadix

public PriorityQueueRadix(int keySize)

Method Detail

insert

public HandlePQ insert(int key,
                       java.lang.Object value)

Appends a wrapper object with the value and its key to a list in the array The key is used as the radix postion of the array. Also, we keep track of the lowest key value inserted into the array

Parameters:

key - the key value of the object

value - the object to be stored in the queue

Returns:

the wrapper object the holds the key and the object values

min

public HandlePQ min()

Returns the smallest key value in the Priority Queue

Returns:

the object with the smallest key value in the Priority Queue

extractMin

public HandlePQ extractMin()

Extracts the object with the smallest key value from the array Then the array is traversed to find the next smallest key

Returns:

the wrapper object with the smallest key value

decreaseKey

public boolean decreaseKey(HandlePQ key,
                           int newKey)

Decreases the key value of the specified element. If the newKey is >= the current key value, false is returned.

Parameters:

h - the HandlePQ whose key value needs to be modified

newKey - the new value

Returns:

true if the key value was changes successfuly, false if the key value was not decreased.

isEmpty

public boolean isEmpty()

Returns true if the Priority Queue is empty

Returns:

true if there are no elements in the Priority Queue

toString

public java.lang.String toString()

Return a list of element stored inside the Priority Queue

Overrides:

toString in class java.lang.Object

Returns:

string value of all the elements in the queue