public class LongHeapPriorityQueue extends java.lang.Object implements LongPriorityQueue, 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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LongHeapPriorityQueue()
Creates a new empty queue using the natural order.
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LongHeapPriorityQueue(java.util.Collection<? extends java.lang.Long> collection)
Creates a queue using the elements in a collection using the natural order.
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LongHeapPriorityQueue(java.util.Collection<? extends java.lang.Long> collection,
LongComparator c)
Creates a queue using the elements in a collection using a given comparator.
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LongHeapPriorityQueue(int capacity)
Creates a new empty queue with a given capacity and using the natural order.
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LongHeapPriorityQueue(int capacity,
LongComparator c)
Creates a new empty queue with a given capacity and comparator.
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LongHeapPriorityQueue(long[] a)
Wraps a given array in a queue using the natural order.
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LongHeapPriorityQueue(long[] a,
int size)
Wraps a given array in a queue using the natural order.
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LongHeapPriorityQueue(long[] a,
int size,
LongComparator c)
Wraps a given array in a queue using a given comparator.
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LongHeapPriorityQueue(long[] a,
LongComparator c)
Wraps a given array in a queue using a given comparator.
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LongHeapPriorityQueue(LongCollection collection)
Creates a queue using the elements in a type-specific collection using the natural order.
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LongHeapPriorityQueue(LongCollection collection,
LongComparator c)
Creates a queue using the elements in a type-specific collection using a given comparator.
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LongHeapPriorityQueue(LongComparator c)
Creates a new empty queue with a given 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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LongComparator |
comparator()
Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
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long |
dequeueLong()
Dequeues the first element from the queue.
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void |
enqueue(long x)
Enqueues a new element.
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long |
firstLong()
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, lastLong
isEmpty
public LongHeapPriorityQueue(int capacity, LongComparator c)
capacity
- the initial capacity of this queue.c
- the comparator used in this queue, or null
for the natural order.public LongHeapPriorityQueue(int capacity)
capacity
- the initial capacity of this queue.public LongHeapPriorityQueue(LongComparator c)
c
- the comparator used in this queue, or null
for the natural order.public LongHeapPriorityQueue()
public LongHeapPriorityQueue(long[] a, int size, LongComparator 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 LongHeapPriorityQueue(long[] a, LongComparator 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 LongHeapPriorityQueue(long[] 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 LongHeapPriorityQueue(long[] 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 LongHeapPriorityQueue(LongCollection collection, LongComparator 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 LongHeapPriorityQueue(LongCollection 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 LongHeapPriorityQueue(java.util.Collection<? extends java.lang.Long> collection, LongComparator 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 LongHeapPriorityQueue(java.util.Collection<? extends java.lang.Long> 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(long x)
LongPriorityQueue
enqueue
in interface LongPriorityQueue
x
- the element to enqueue.PriorityQueue.enqueue(Object)
public long dequeueLong()
LongPriorityQueue
dequeueLong
in interface LongPriorityQueue
LongPriorityQueue.dequeue()
public long firstLong()
LongPriorityQueue
firstLong
in interface LongPriorityQueue
LongPriorityQueue.first()
public void changed()
PriorityQueue
This default implementation just throws an UnsupportedOperationException
.
changed
in interface PriorityQueue<java.lang.Long>
public int size()
PriorityQueue
size
in interface PriorityQueue<java.lang.Long>
public void clear()
PriorityQueue
clear
in interface PriorityQueue<java.lang.Long>
public void trim()
size()
elements.public LongComparator comparator()
LongPriorityQueue
comparator
in interface LongPriorityQueue
comparator
in interface PriorityQueue<java.lang.Long>
PriorityQueue.comparator()