it.unimi.dsi.fastutil.longs
Class LongArrayFIFOQueue

java.lang.Object
  it.unimi.dsi.fastutil.AbstractPriorityQueue<java.lang.Long>
      it.unimi.dsi.fastutil.longs.AbstractLongPriorityQueue
          it.unimi.dsi.fastutil.longs.LongArrayFIFOQueue

All Implemented Interfaces:

LongPriorityQueue, PriorityQueue<java.lang.Long>

public class LongArrayFIFOQueue
extends AbstractLongPriorityQueue

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).

Field Summary

static int

INITIAL_CAPACITY The standard initial capacity of a queue.

Constructor Summary

LongArrayFIFOQueue()
Creates a new empty queue with standard initial capacity.

LongArrayFIFOQueue(int capacity)
Creates a new empty queue with given capacity.

Method Summary

void	clear() Removes all elements from this queue.
LongComparator	comparator() Returns null (FIFO queues have no comparator).
long	dequeueLastLong() Dequeues the last element from the queue.
long	dequeueLong() Dequeues the first element from the queue.
void	enqueue(long x) Enqueues a new element.
void	enqueueFirst(long x) Enqueues a new element as the first element (in dequeuing order) of the queue.
long	firstLong() Returns the first element of the queue.
long	lastLong() Returns the last element of the queue.
int	size() Returns the number of elements in this queue.
void	trim() Trims the queue to the smallest possible size.

Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongPriorityQueue

dequeue, enqueue, first, last

Methods inherited from class it.unimi.dsi.fastutil.AbstractPriorityQueue

changed, isEmpty

Methods inherited from class java.lang.Object

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

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

Constructor Detail

LongArrayFIFOQueue

public LongArrayFIFOQueue(int capacity)

Creates a new empty queue with given capacity.

Parameters:

capacity - the initial capacity of this queue.

LongArrayFIFOQueue

public LongArrayFIFOQueue()

Creates a new empty queue with standard initial capacity.

Method Detail

comparator

public LongComparator comparator()

Returns null (FIFO queues have no comparator).

Returns:

null.

See Also:

PriorityQueue.comparator()

dequeueLong

public long dequeueLong()

Description copied from interface: LongPriorityQueue

Dequeues the first element from the queue.

Returns:

the dequeued element.

dequeueLastLong

public long dequeueLastLong()

Dequeues the last element from the queue.

Returns:

the dequeued element.

Throws:

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

enqueue

public void enqueue(long x)

Description copied from interface: LongPriorityQueue

Enqueues a new element.

Parameters:

x - the element to enqueue.

enqueueFirst

public void enqueueFirst(long x)

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

firstLong

public long firstLong()

Returns the first element of the queue.

Returns:

the first element of the queue.

lastLong

public long lastLong()

Returns the last element of the queue.

Specified by:

lastLong in interface LongPriorityQueue

Overrides:

lastLong in class AbstractLongPriorityQueue

Returns:

the last element of the queue.

clear

public void clear()

Description copied from interface: PriorityQueue

Removes all elements from this queue.

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.

Returns:

the number of elements in this queue.