DoubleHeapPriorityQueue (fastutil-reference-char-maps 8.3.1 API)

java.lang.Object
- it.unimi.dsi.fastutil.doubles.DoubleHeapPriorityQueue

All Implemented Interfaces:

DoublePriorityQueue, PriorityQueue<Double>, Serializable
```
public class DoubleHeapPriorityQueue
extends Object
implements DoublePriorityQueue, 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 DoubleComparator`	`c` The type-specific comparator used in this queue.
`protected double[]`	`heap` The heap array.
`protected int`	`size` The number of elements in this queue.

Constructor Summary

Constructors
Constructor and Description
`DoubleHeapPriorityQueue()` Creates a new empty queue using the natural order.
`DoubleHeapPriorityQueue(Collection<? extends Double> collection)` Creates a queue using the elements in a collection using the natural order.
`DoubleHeapPriorityQueue(Collection<? extends Double> collection, DoubleComparator c)` Creates a queue using the elements in a collection using a given comparator.
`DoubleHeapPriorityQueue(double[] a)` Wraps a given array in a queue using the natural order.
`DoubleHeapPriorityQueue(double[] a, DoubleComparator c)` Wraps a given array in a queue using a given comparator.
`DoubleHeapPriorityQueue(double[] a, int size)` Wraps a given array in a queue using the natural order.
`DoubleHeapPriorityQueue(double[] a, int size, DoubleComparator c)` Wraps a given array in a queue using a given comparator.
`DoubleHeapPriorityQueue(DoubleCollection collection)` Creates a queue using the elements in a type-specific collection using the natural order.
`DoubleHeapPriorityQueue(DoubleCollection collection, DoubleComparator c)` Creates a queue using the elements in a type-specific collection using a given comparator.
`DoubleHeapPriorityQueue(DoubleComparator c)` Creates a new empty queue with a given comparator.
`DoubleHeapPriorityQueue(int capacity)` Creates a new empty queue with a given capacity and using the natural order.
`DoubleHeapPriorityQueue(int capacity, DoubleComparator c)` Creates a new empty queue with a given capacity and 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.
`DoubleComparator`	`comparator()` Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
`double`	`dequeueDouble()` Dequeues the first element from the queue.
`void`	`enqueue(double x)` Enqueues a new element.
`double`	`firstDouble()` 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.doubles.DoublePriorityQueue
dequeue, enqueue, first, last, lastDouble

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

- Field Detail
  - heap
```
protected transient double[] heap
```
    The heap array.
  - size
```
protected int size
```
    The number of elements in this queue.
  - c
```
protected DoubleComparator c
```
    The type-specific comparator used in this queue.
- Constructor Detail
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(int capacity,
                               DoubleComparator 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(int capacity)
```
    Creates a new empty queue with a given capacity and using the natural order.
    
    Parameters:
    
    capacity - the initial capacity of this queue.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(DoubleComparator c)
```
    Creates a new empty queue with a given comparator.
    
    Parameters:
    
    c - the comparator used in this queue, or null for the natural order.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue()
```
    Creates a new empty queue using the natural order.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(double[] a,
                               int size,
                               DoubleComparator 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(double[] a,
                               DoubleComparator 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(double[] 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(double[] 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(DoubleCollection collection,
                               DoubleComparator c)
```
    Creates a queue using the elements in a type-specific 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(DoubleCollection collection)
```
    Creates a queue using the elements in a type-specific 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(Collection<? extends Double> collection,
                               DoubleComparator 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.
  - DoubleHeapPriorityQueue
```
public DoubleHeapPriorityQueue(Collection<? extends Double> 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(double x)
```
    Description copied from interface: DoublePriorityQueue
    
    Enqueues a new element.
    
    Specified by:
    
    enqueue in interface DoublePriorityQueue
    
    Parameters:
    
    x - the element to enqueue.
    
    See Also:
    
    PriorityQueue.enqueue(Object)
  - dequeueDouble
```
public double dequeueDouble()
```
    Description copied from interface: DoublePriorityQueue
    
    Dequeues the first element from the queue.
    
    Specified by:
    
    dequeueDouble in interface DoublePriorityQueue
    
    Returns:
    
    the dequeued element.
    
    See Also:
    
    DoublePriorityQueue.dequeue()
  - firstDouble
```
public double firstDouble()
```
    Description copied from interface: DoublePriorityQueue
    
    Returns the first element of the queue.
    
    Specified by:
    
    firstDouble in interface DoublePriorityQueue
    
    Returns:
    
    the first element.
    
    See Also:
    
    DoublePriorityQueue.first()
  - 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<Double>
  - size
```
public int size()
```
    Description copied from interface: PriorityQueue
    
    Returns the number of elements in this queue.
    
    Specified by:
    
    size in interface PriorityQueue<Double>
    
    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<Double>
  - trim
```
public void trim()
```
    Trims the underlying heap array so that it has exactly size() elements.
  - comparator
```
public DoubleComparator comparator()
```
    Description copied from interface: DoublePriorityQueue
    
    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().
    
    Specified by:
    
    comparator in interface DoublePriorityQueue
    
    Specified by:
    
    comparator in interface PriorityQueue<Double>
    
    Returns:
    
    the comparator associated with this priority queue.
    
    See Also:
    
    PriorityQueue.comparator()

Class DoubleHeapPriorityQueue

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface it.unimi.dsi.fastutil.doubles.DoublePriorityQueue

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

Field Detail

heap

size

c

Constructor Detail

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

DoubleHeapPriorityQueue

Method Detail

enqueue

dequeueDouble

firstDouble

changed

size

clear

trim

comparator