it.unimi.dsi.fastutil.shorts

Class ShortArrayFIFOQueue

java.lang.Object

it.unimi.dsi.fastutil.shorts.ShortArrayFIFOQueue

All Implemented Interfaces:

it.unimi.dsi.fastutil.PriorityQueue<java.lang.Short>, ShortPriorityQueue, java.io.Serializable

public class ShortArrayFIFOQueue
extends java.lang.Object
implements ShortPriorityQueue, java.io.Serializable

A type-specific array-based FIFO queue, supporting also deque operations.

Instances of this class represent a FIFO queue using a backing array in a circular way. The array is enlarged and shrunk as needed. You can use the trim() method to reduce its memory usage, if necessary.

This class provides additional methods that implement a deque (double-ended queue).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected short[]	array The backing array.
protected int	end The end position in array.
static int	INITIAL_CAPACITY The standard initial capacity of a queue.
protected int	length The current (cached) length of array.
protected int	start The start position in array.

Constructor Summary

Constructors

Constructor and Description
ShortArrayFIFOQueue() Creates a new empty queue with standard initial capacity.
ShortArrayFIFOQueue(int capacity) Creates a new empty queue with given capacity.

Method Summary

Modifier and Type	Method and Description
void	clear()
it.unimi.dsi.fastutil.shorts.ShortComparator	comparator() Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
short	dequeueLastShort() Dequeues the last element from the queue.
short	dequeueShort() Dequeues the first element from the queue.
void	enqueue(short x) Enqueues a new element.
void	enqueueFirst(short x) Enqueues a new element as the first element (in dequeuing order) of the queue.
short	firstShort() Returns the first element of the queue.
short	lastShort() Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).
int	size()
void	trim() Trims the queue to the smallest possible size.

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortPriorityQueue

dequeue, enqueue, first, last

Methods inherited from interface it.unimi.dsi.fastutil.PriorityQueue

changed, isEmpty

Field Detail

INITIAL_CAPACITY

public static final int INITIAL_CAPACITY

The standard initial capacity of a queue.

See Also:

Constant Field Values

array

protected transient short[] array

The backing array.

length

protected transient int length

The current (cached) length of array.

start

protected transient int start

The start position in array. It is always strictly smaller than length.

end

protected transient int end

The end position in array. It is always strictly smaller than length. Might be actually smaller than start because array is used cyclically.

Constructor Detail

ShortArrayFIFOQueue

public ShortArrayFIFOQueue(int capacity)

Creates a new empty queue with given capacity.

Parameters:

capacity - the initial capacity of this queue.

ShortArrayFIFOQueue

public ShortArrayFIFOQueue()

Creates a new empty queue with standard initial capacity.

Method Detail

comparator

public it.unimi.dsi.fastutil.shorts.ShortComparator comparator()

Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.

Specified by:

comparator in interface it.unimi.dsi.fastutil.PriorityQueue<java.lang.Short>

Specified by:

comparator in interface ShortPriorityQueue

Returns:

the comparator associated with this priority queue.

See Also:

PriorityQueue.comparator()

dequeueShort

public short dequeueShort()

Description copied from interface: ShortPriorityQueue

Dequeues the first element from the queue.

Specified by:

dequeueShort in interface ShortPriorityQueue

Returns:

the dequeued element.

See Also:

ShortPriorityQueue.dequeue()

dequeueLastShort

public short dequeueLastShort()

Dequeues the last element from the queue.

Returns:

the dequeued element.

Throws:

java.util.NoSuchElementException - if the queue is empty.

enqueue

public void enqueue(short x)

Description copied from interface: ShortPriorityQueue

Enqueues a new element.

Specified by:

enqueue in interface ShortPriorityQueue

Parameters:

x - the element to enqueue.

See Also:

PriorityQueue.enqueue(Object)

enqueueFirst

public void enqueueFirst(short x)

Enqueues a new element as the first element (in dequeuing order) of the queue.

Parameters:

x - the element to enqueue.

firstShort

public short firstShort()

Description copied from interface: ShortPriorityQueue

Returns the first element of the queue.

Specified by:

firstShort in interface ShortPriorityQueue

Returns:

the first element.

See Also:

ShortPriorityQueue.first()

lastShort

public short lastShort()

Description copied from interface: ShortPriorityQueue

Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).

This default implementation just throws an UnsupportedOperationException.

Specified by:

lastShort in interface ShortPriorityQueue

Returns:

the last element.

See Also:

ShortPriorityQueue.last()

clear

public void clear()

Specified by:

clear in interface it.unimi.dsi.fastutil.PriorityQueue<java.lang.Short>

trim

public void trim()

Trims the queue to the smallest possible size.

size

public int size()

Specified by:

size in interface it.unimi.dsi.fastutil.PriorityQueue<java.lang.Short>