Package it.unimi.dsi.fastutil.chars

Class CharArrayFIFOQueue

java.lang.Object

it.unimi.dsi.fastutil.chars.CharArrayFIFOQueue

All Implemented Interfaces:

CharPriorityQueue, PriorityQueue<Character>, Serializable

public class CharArrayFIFOQueue
extends Object
implements CharPriorityQueue, 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	Description
static int	INITIAL_CAPACITY	The standard initial capacity of a queue.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all elements from this queue.
CharComparator	comparator()	Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
char	dequeueChar()	Dequeues the first element from the queue.
char	dequeueLastChar()	Dequeues the last element from the queue.
void	enqueue(char x)	Enqueues a new element.
void	enqueueFirst(char x)	Enqueues a new element as the first element (in dequeuing order) of the queue.
char	firstChar()	Returns the first element of the queue.
char	lastChar()	Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).
int	size()	Returns the number of elements in this queue.
void	trim()	Trims the queue to the smallest possible size.

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharPriorityQueue

dequeue, enqueue, first, last

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

changed, isEmpty

Field Details

INITIAL_CAPACITY

public static final int INITIAL_CAPACITY

The standard initial capacity of a queue.

See Also:

Constant Field Values

Constructor Details

CharArrayFIFOQueue

public CharArrayFIFOQueue(int capacity)

Creates a new empty queue with given capacity.

Parameters:

capacity - the initial capacity of this queue.

CharArrayFIFOQueue

public CharArrayFIFOQueue()

Creates a new empty queue with standard initial capacity.

Method Details

comparator

public CharComparator comparator()

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

Note that this specification strengthens the one given in PriorityQueue.comparator().

This implementation returns null (FIFO queues have no comparator).

Specified by:

comparator in interface CharPriorityQueue

Specified by:

comparator in interface PriorityQueue<Character>

Returns:

the comparator associated with this priority queue.

See Also:

PriorityQueue.comparator()

dequeueChar

public char dequeueChar()

Description copied from interface: CharPriorityQueue

Dequeues the first element from the queue.

Specified by:

dequeueChar in interface CharPriorityQueue

Returns:

the dequeued element.

See Also:

CharPriorityQueue.dequeue()

dequeueLastChar

public char dequeueLastChar()

Dequeues the last element from the queue.

Returns:

the dequeued element.

Throws:

NoSuchElementException - if the queue is empty.

enqueue

public void enqueue(char x)

Description copied from interface: CharPriorityQueue

Enqueues a new element.

Specified by:

enqueue in interface CharPriorityQueue

Parameters:

x - the element to enqueue.

See Also:

PriorityQueue.enqueue(Object)

enqueueFirst

public void enqueueFirst(char x)

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

Parameters:

x - the element to enqueue.

firstChar

public char firstChar()

Description copied from interface: CharPriorityQueue

Returns the first element of the queue.

Specified by:

firstChar in interface CharPriorityQueue

Returns:

the first element.

See Also:

CharPriorityQueue.first()

lastChar

public char lastChar()

Description copied from interface: CharPriorityQueue

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:

lastChar in interface CharPriorityQueue

Returns:

the last element.

See Also:

CharPriorityQueue.last()

clear

public void clear()

Description copied from interface: PriorityQueue

Removes all elements from this queue.

Specified by:

clear in interface PriorityQueue<Character>

trim

public void trim()

Trims the queue to the smallest possible size.

size

public int size()

Description copied from interface: PriorityQueue

Returns the number of elements in this queue.

Specified by:

size in interface PriorityQueue<Character>

Returns:

the number of elements in this queue.