public class DoubleHeapPriorityQueue extends java.lang.Object implements DoublePriorityQueue, java.io.Serializable
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.
Constructor and Description |
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DoubleHeapPriorityQueue()
Creates a new empty queue using the natural order.
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DoubleHeapPriorityQueue(java.util.Collection<? extends java.lang.Double> collection)
Creates a queue using the elements in a collection using the natural order.
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DoubleHeapPriorityQueue(java.util.Collection<? extends java.lang.Double> collection,
DoubleComparator c)
Creates a queue using the elements in a collection using a given comparator.
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DoubleHeapPriorityQueue(double[] a)
Wraps a given array in a queue using the natural order.
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DoubleHeapPriorityQueue(double[] a,
DoubleComparator c)
Wraps a given array in a queue using a given comparator.
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DoubleHeapPriorityQueue(double[] a,
int size)
Wraps a given array in a queue using the natural order.
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DoubleHeapPriorityQueue(double[] a,
int size,
DoubleComparator c)
Wraps a given array in a queue using a given comparator.
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DoubleHeapPriorityQueue(DoubleCollection collection)
Creates a queue using the elements in a type-specific collection using the natural order.
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DoubleHeapPriorityQueue(DoubleCollection collection,
DoubleComparator c)
Creates a queue using the elements in a type-specific collection using a given comparator.
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DoubleHeapPriorityQueue(DoubleComparator c)
Creates a new empty queue with a given comparator.
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DoubleHeapPriorityQueue(int capacity)
Creates a new empty queue with a given capacity and using the natural order.
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DoubleHeapPriorityQueue(int capacity,
DoubleComparator c)
Creates a new empty queue with a given capacity and comparator.
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Modifier and Type | Method and Description |
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void |
changed()
Notifies the queue that the first element has changed (optional operation).
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void |
clear()
Removes all elements from this queue.
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DoubleComparator |
comparator()
Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
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double |
dequeueDouble()
Dequeues the first element from the queue.
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void |
enqueue(double x)
Enqueues a new element.
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double |
firstDouble()
Returns the first element of the queue.
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int |
size()
Returns the number of elements in this queue.
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void |
trim()
Trims the underlying heap array so that it has exactly
size() elements. |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
dequeue, enqueue, first, last, lastDouble
isEmpty
public DoubleHeapPriorityQueue(int capacity, DoubleComparator c)
capacity
- the initial capacity of this queue.c
- the comparator used in this queue, or null
for the natural order.public DoubleHeapPriorityQueue(int capacity)
capacity
- the initial capacity of this queue.public DoubleHeapPriorityQueue(DoubleComparator c)
c
- the comparator used in this queue, or null
for the natural order.public DoubleHeapPriorityQueue()
public DoubleHeapPriorityQueue(double[] a, int size, DoubleComparator c)
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).
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.public DoubleHeapPriorityQueue(double[] a, DoubleComparator c)
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).
a
- an array.c
- the comparator used in this queue, or null
for the natural order.public DoubleHeapPriorityQueue(double[] a, int size)
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).
a
- an array.size
- the number of elements to be included in the queue.public DoubleHeapPriorityQueue(double[] a)
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).
a
- an array.public DoubleHeapPriorityQueue(DoubleCollection collection, DoubleComparator c)
This constructor is more efficient than enqueing the elements of collection
one by one.
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.public DoubleHeapPriorityQueue(DoubleCollection collection)
This constructor is
more efficient than enqueing the elements of collection
one by one.
collection
- a collection; its elements will be used to initialize the queue.public DoubleHeapPriorityQueue(java.util.Collection<? extends java.lang.Double> collection, DoubleComparator c)
This constructor is more efficient than enqueing the elements of collection
one by one.
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.public DoubleHeapPriorityQueue(java.util.Collection<? extends java.lang.Double> collection)
This constructor is
more efficient than enqueing the elements of collection
one by one.
collection
- a collection; its elements will be used to initialize the queue.public void enqueue(double x)
DoublePriorityQueue
enqueue
in interface DoublePriorityQueue
x
- the element to enqueue.PriorityQueue.enqueue(Object)
public double dequeueDouble()
DoublePriorityQueue
dequeueDouble
in interface DoublePriorityQueue
DoublePriorityQueue.dequeue()
public double firstDouble()
DoublePriorityQueue
firstDouble
in interface DoublePriorityQueue
DoublePriorityQueue.first()
public void changed()
PriorityQueue
This default implementation just throws an UnsupportedOperationException
.
changed
in interface PriorityQueue<java.lang.Double>
public int size()
PriorityQueue
size
in interface PriorityQueue<java.lang.Double>
public void clear()
PriorityQueue
clear
in interface PriorityQueue<java.lang.Double>
public void trim()
size()
elements.public DoubleComparator comparator()
DoublePriorityQueue
comparator
in interface DoublePriorityQueue
comparator
in interface PriorityQueue<java.lang.Double>
PriorityQueue.comparator()