mauda.plugin.fibheap
Class FibHeap

java.lang.Object
  mauda.plugin.fibheap.FibHeap

All Implemented Interfaces:

Copyable, JedasMainCompObj

Direct Known Subclasses:

FibHeapExt

public class FibHeap
extends java.lang.Object
implements JedasMainCompObj, Copyable

Implements and animates the data structure 'Fibonacci heap' (F-heap) and the operations defined to manipulate the structure.
F-heaps are one way of implementing priority queues. They consist of nodes ('tasks') with given keys ('priorities'). At any time, a new node may be added, the node with minimum key can be accessed or removed from the queue, the key value of a given node may be decreased, or a given node may be deleted.
Calling the constructor with an instance of jedas.Scheduler and adding the FibHeap to a jedas.CompPanel will animate all the operations manipulating the F-heap structure.
In addition, this class offers a simple way to analyze the actual time complexity of the individual heap operations. In order to analyze a heap manipulation, call getCount() after executing the respective operation.
The analysis is idealized in the following sense:

• All operations with complexity O(1) take 1 time unit.
• All other operations take 1 time unit per sub-operation (such as linking or cutting nodes).
• deletemin() takes l additional steps, where l equals the length of the array needed to consolidate the root list [i>l = O(log heapsize)].

Version:

2.02 (14/08/03)

Author:

Tobias Lauer

Field Summary

static int	DETAIL
static int	MORE
static int	NONE Detail levels of accompanying text.
static int	NORMAL
static SubOperationQueue	subOperations

Constructor Summary

FibHeap()
Creates a new, empty FibHeap.

Method Summary

int	accessmin() Returns the minimum key in this Fibonacci heap.
void	add(SubOperation so)
void	clearSubOperationQueue()
java.lang.Object	copy()
java.lang.Object	copyDS()
void	decreasekey(FibNode N, int k) Decreases the key of the specified node to the specified value.
java.lang.Object	deepCopy() Performs a deep copy of the implemented data-structure
int	delete(FibNode node) Deletes the specified node from this Fibonacci heap.
int	deletemin() Deletes the node with minimum key in this Fibonacci heap.
int	getCount() Call this method to analyze a just completed heap operation.
int	getHeapSize()
static boolean	getKeyColorMode()
jedas.CompObj	getMainCompObj() Returns the main CompObj which to visualize in the JEDAS animation-area.
SubOperationQueue	getSubOperationQueue()
FibNode	insert(int k) Inserts a new node to this Fibonacci heap.
boolean	isEmpty()
int	maxRank() Returns the maximum possible rank of a node in this FibHeap.
void	meld(FibHeap other) Melds another FibHeap into this one.
void	resetCount() Resets the step counter to 0.
static void	setKeyColorMode(boolean b) Sets the 'key color' mode.
static void	setTextMode(int mode) Sets the 'text mode' to accompany operations by text.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

subOperations

public static SubOperationQueue subOperations

NONE

public static final int NONE

Detail levels of accompanying text.

See Also:

Constant Field Values

NORMAL

public static final int NORMAL

See Also:

Constant Field Values

MORE

public static final int MORE

See Also:

Constant Field Values

DETAIL

public static final int DETAIL

See Also:

Constant Field Values

Constructor Detail

FibHeap

public FibHeap()

Creates a new, empty FibHeap.

Method Detail

isEmpty

public boolean isEmpty()

Returns:

true if this FibHeap is empty

meld

public void meld(FibHeap other)

Melds another FibHeap into this one. The other rootlist is inserted to the right of the given node.

Parameters:

other - the FibHeap to be joined with this one

insert

public FibNode insert(int k)

Inserts a new node to this Fibonacci heap. Creates a new FibNode with given key and inserts in rootlist right of the min node.

Parameters:

k - key of new FibNode

Returns:

new FibNode with key k

accessmin

public int accessmin()

Returns the minimum key in this Fibonacci heap. If FibHeap is empty, returns -1.

Returns:

minimum key (or 999)

deletemin

public int deletemin()

Deletes the node with minimum key in this Fibonacci heap. Then consolidates rootlist to restore heap.

Returns:

minimum key

decreasekey

public void decreasekey(FibNode N,
                        int k)

Decreases the key of the specified node to the specified value. If necessary (to restore heap), cuts the node off its parent and inserts into rootlist. In this case, the parent will then be marked, or, if marked already, also cut off, and so on.

Parameters:

N - node whose key is to be decreased

k - new key value

delete

public int delete(FibNode node)

Deletes the specified node from this Fibonacci heap. If the node is the min node, the deletemin method will be carried out.

Parameters:

node - node to be deleted

Returns:

key of the deleted node

getHeapSize

public int getHeapSize()

Returns:

the number of nodes in this Fibonacci heap

getCount

public int getCount()

Call this method to analyze a just completed heap operation. This will give you that operation's actual time complexity (see class intro for more details).

Returns:

the current value of the step counter.

resetCount

public void resetCount()

Resets the step counter to 0. This method is called at the start of all heap operations. After executing the operation, use getCount() to get the time complexity of that operation (see class intro for more details).

getKeyColorMode

public static boolean getKeyColorMode()

Returns:

TRUE iff 'key color' mode is active

setKeyColorMode

public static void setKeyColorMode(boolean b)

Sets the 'key color' mode. In this mode, the fill color of each node relfects that node's key value.

Parameters:

b - TRUE iff 'key color' is on

setTextMode

public static void setTextMode(int mode)

Sets the 'text mode' to accompany operations by text. Possible values are: NONE, NORMAL, DETAIL

Parameters:

mode - the text mode

maxRank

public int maxRank()

Returns the maximum possible rank of a node in this FibHeap. This number is in O(log n) where n is the heap size.

Returns:

maximum possible rank of a node

getMainCompObj

public jedas.CompObj getMainCompObj()

Description copied from interface: JedasMainCompObj

Returns the main CompObj which to visualize in the JEDAS animation-area.

Specified by:

getMainCompObj in interface JedasMainCompObj

Returns:

CompObj to view in JEDAS-animation-panel

getSubOperationQueue

public SubOperationQueue getSubOperationQueue()

add

public void add(SubOperation so)

clearSubOperationQueue

public void clearSubOperationQueue()

deepCopy

public java.lang.Object deepCopy()

Description copied from interface: Copyable

Performs a deep copy of the implemented data-structure

Specified by:

deepCopy in interface Copyable

Returns:

copy of the data-structure

copy

public java.lang.Object copy()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

copyDS

public java.lang.Object copyDS()