public class DoubleHeapPriorityQueue extends AbstractDoublePriorityQueue
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(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(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 |
|---|---|
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 sorted set, 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. |
dequeue, enqueue, first, last, lastDoubleisEmptyequals, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitisEmptypublic 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 void enqueue(double x)
DoublePriorityQueuex - the element to enqueue.public double dequeueDouble()
DoublePriorityQueuepublic double firstDouble()
DoublePriorityQueuepublic void changed()
PriorityQueuechanged in interface PriorityQueue<Double>changed in class AbstractPriorityQueue<Double>public int size()
PriorityQueuepublic void clear()
PriorityQueuepublic void trim()
size() elements.public DoubleComparator comparator()
DoublePriorityQueueNote that this specification strengthens the one given in PriorityQueue.comparator().
null if it uses its elements' natural ordering.PriorityQueue.comparator()