ObjectHeapPriorityQueue (fastutil-object-short-maps 8.3.1 API)

java.lang.Object
- it.unimi.dsi.fastutil.objects.ObjectHeapPriorityQueue<K>

All Implemented Interfaces:

PriorityQueue<K>, Serializable
```
public class ObjectHeapPriorityQueue<K>
extends Object
implements PriorityQueue<K>, Serializable
```
A type-specific heap-based priority queue.
Instances of this class represent a priority queue using a heap. The heap is enlarged as needed, but it is never shrunk. Use the trim() method to reduce its size, if necessary.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected Comparator<? super K>`	`c` The type-specific comparator used in this queue.
`protected K[]`	`heap` The heap array.
`protected int`	`size` The number of elements in this queue.

Constructor Summary

Constructors
Constructor and Description
`ObjectHeapPriorityQueue()` Creates a new empty queue using the natural order.
`ObjectHeapPriorityQueue(Collection<? extends K> collection)` Creates a queue using the elements in a collection using the natural order.
`ObjectHeapPriorityQueue(Collection<? extends K> collection, Comparator<? super K> c)` Creates a queue using the elements in a collection using a given comparator.
`ObjectHeapPriorityQueue(Comparator<? super K> c)` Creates a new empty queue with a given comparator.
`ObjectHeapPriorityQueue(int capacity)` Creates a new empty queue with a given capacity and using the natural order.
`ObjectHeapPriorityQueue(int capacity, Comparator<? super K> c)` Creates a new empty queue with a given capacity and comparator.
`ObjectHeapPriorityQueue(K[] a)` Wraps a given array in a queue using the natural order.
`ObjectHeapPriorityQueue(K[] a, Comparator<? super K> c)` Wraps a given array in a queue using a given comparator.
`ObjectHeapPriorityQueue(K[] a, int size)` Wraps a given array in a queue using the natural order.
`ObjectHeapPriorityQueue(K[] a, int size, Comparator<? super K> c)` Wraps a given array in a queue using a given comparator.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`changed()` Notifies the queue that the first element has changed (optional operation).
`void`	`clear()` Removes all elements from this queue.
`Comparator<? super K>`	`comparator()` Returns the comparator associated with this queue, or `null` if it uses its elements' natural ordering.
`K`	`dequeue()` Dequeues the first element from the queue.
`void`	`enqueue(K x)` Enqueues a new element.
`K`	`first()` Returns the first element of the queue.
`int`	`size()` Returns the number of elements in this queue.
`void`	`trim()` Trims the underlying heap array so that it has exactly `size()` elements.

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.PriorityQueue
isEmpty, last

- Field Detail
  - heap
```
protected transient K[] heap
```
    The heap array.
  - size
```
protected int size
```
    The number of elements in this queue.
  - c
```
protected Comparator<? super K> c
```
    The type-specific comparator used in this queue.
- Constructor Detail
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(int capacity,
                               Comparator<? super K> c)
```
    Creates a new empty queue with a given capacity and comparator.
    
    Parameters:
    
    capacity - the initial capacity of this queue.
    
    c - the comparator used in this queue, or null for the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(int capacity)
```
    Creates a new empty queue with a given capacity and using the natural order.
    
    Parameters:
    
    capacity - the initial capacity of this queue.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(Comparator<? super K> c)
```
    Creates a new empty queue with a given comparator.
    
    Parameters:
    
    c - the comparator used in this queue, or null for the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue()
```
    Creates a new empty queue using the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(K[] a,
                               int size,
                               Comparator<? super K> c)
```
    Wraps a given array in a queue using a given comparator.
    The queue returned by this method will be backed by the given array. The first size element of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).
    
    Parameters:
    
    a - an array.
    
    size - the number of elements to be included in the queue.
    
    c - the comparator used in this queue, or null for the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(K[] a,
                               Comparator<? super K> c)
```
    Wraps a given array in a queue using a given comparator.
    The queue returned by this method will be backed by the given array. The elements of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).
    
    Parameters:
    
    a - an array.
    
    c - the comparator used in this queue, or null for the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(K[] a,
                               int size)
```
    Wraps a given array in a queue using the natural order.
    The queue returned by this method will be backed by the given array. The first size element of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).
    
    Parameters:
    
    a - an array.
    
    size - the number of elements to be included in the queue.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(K[] a)
```
    Wraps a given array in a queue using the natural order.
    The queue returned by this method will be backed by the given array. The elements of the array will be rearranged so to form a heap (this is more efficient than enqueing the elements of a one by one).
    
    Parameters:
    
    a - an array.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(Collection<? extends K> collection,
                               Comparator<? super K> c)
```
    Creates a queue using the elements in a collection using a given comparator.
    This constructor is more efficient than enqueing the elements of collection one by one.
    
    Parameters:
    
    collection - a collection; its elements will be used to initialize the queue.
    
    c - the comparator used in this queue, or null for the natural order.
  - ObjectHeapPriorityQueue
```
public ObjectHeapPriorityQueue(Collection<? extends K> collection)
```
    Creates a queue using the elements in a collection using the natural order.
    This constructor is more efficient than enqueing the elements of collection one by one.
    
    Parameters:
    
    collection - a collection; its elements will be used to initialize the queue.
- Method Detail
  - enqueue
```
public void enqueue(K x)
```
    Description copied from interface: PriorityQueue
    
    Enqueues a new element.
    
    Specified by:
    
    enqueue in interface PriorityQueue<K>
    
    Parameters:
    
    x - the element to enqueue.
  - dequeue
```
public K dequeue()
```
    Description copied from interface: PriorityQueue
    
    Dequeues the first element from the queue.
    
    Specified by:
    
    dequeue in interface PriorityQueue<K>
    
    Returns:
    
    the dequeued element.
  - first
```
public K first()
```
    Description copied from interface: PriorityQueue
    
    Returns the first element of the queue.
    
    Specified by:
    
    first in interface PriorityQueue<K>
    
    Returns:
    
    the first element.
  - changed
```
public void changed()
```
    Description copied from interface: PriorityQueue
    
    Notifies the queue that the first element has changed (optional operation).
    This default implementation just throws an UnsupportedOperationException.
    
    Specified by:
    
    changed in interface PriorityQueue<K>
  - size
```
public int size()
```
    Description copied from interface: PriorityQueue
    
    Returns the number of elements in this queue.
    
    Specified by:
    
    size in interface PriorityQueue<K>
    
    Returns:
    
    the number of elements in this queue.
  - clear
```
public void clear()
```
    Description copied from interface: PriorityQueue
    
    Removes all elements from this queue.
    
    Specified by:
    
    clear in interface PriorityQueue<K>
  - trim
```
public void trim()
```
    Trims the underlying heap array so that it has exactly size() elements.
  - comparator
```
public Comparator<? super K> comparator()
```
    Description copied from interface: PriorityQueue
    
    Returns the comparator associated with this queue, or null if it uses its elements' natural ordering.
    
    Specified by:
    
    comparator in interface PriorityQueue<K>
    
    Returns:
    
    the comparator associated with this sorted set, or null if it uses its elements' natural ordering.

Class ObjectHeapPriorityQueue<K>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

heap

size

c

Constructor Detail

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

ObjectHeapPriorityQueue

Method Detail

enqueue

dequeue

first

changed

size

clear

trim

comparator