public class LongArrayIndirectPriorityQueue extends java.lang.Object implements LongIndirectPriorityQueue
Instances of this class use as reference list a reference array,
which must be provided to each constructor, and represent a priority queue
using a backing array of integer indices—all operations are performed
directly on the array. The array is enlarged as needed, but it is never
shrunk. Use the trim()
method to reduce its size, if necessary.
Constructor and Description |
---|
LongArrayIndirectPriorityQueue(long[] refArray)
Creates a new empty queue with capacity equal to the length of the reference array and using the natural order.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int capacity)
Creates a new empty queue with given capacity and using the natural order.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int[] a)
Wraps a given array in a queue using the natural order.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int[] a,
int size)
Wraps a given array in a queue using the natural order.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int[] a,
int size,
LongComparator c)
Wraps a given array in a queue using a given comparator.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int[] a,
LongComparator c)
Wraps a given array in a queue using a given comparator.
|
LongArrayIndirectPriorityQueue(long[] refArray,
int capacity,
LongComparator c)
Creates a new empty queue without elements with a given capacity and comparator.
|
LongArrayIndirectPriorityQueue(long[] refArray,
LongComparator c)
Creates a new empty queue with capacity equal to the length of the reference array and a given comparator.
|
Modifier and Type | Method and Description |
---|---|
void |
allChanged()
Signals the queue that all elements have changed.
|
void |
changed()
Notifies this queue that the first element has changed (optional operation).
|
void |
changed(int index)
Notifies this queue that the specified element has changed (optional operation).
|
void |
clear()
Removes all elements from this queue.
|
LongComparator |
comparator()
Returns the type-specific comparator associated with this queue.
|
int |
dequeue()
Dequeues the first element from this queue.
|
void |
enqueue(int x)
Enqueues a new element.
|
int |
first()
Returns the first element of this queue.
|
int |
front(int[] a)
Writes in the provided array the front of the queue, that is, the set of indices
whose elements have the same priority as the top.
|
int |
last()
Returns the last element of this queue, that is, the element the would be dequeued last (optional operation).
|
boolean |
remove(int index)
Removes the specified element from this queue (optional operation).
|
int |
size()
Returns the number of elements in this queue.
|
java.lang.String |
toString() |
void |
trim()
Trims the backing array so that it has exactly
size() elements. |
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
contains, isEmpty
public LongArrayIndirectPriorityQueue(long[] refArray, int capacity, LongComparator c)
refArray
- the reference array.capacity
- the initial capacity of this queue.c
- the comparator used in this queue, or null
for the natural order.public LongArrayIndirectPriorityQueue(long[] refArray, int capacity)
refArray
- the reference array.capacity
- the initial capacity of this queue.public LongArrayIndirectPriorityQueue(long[] refArray, LongComparator c)
refArray
- the reference array.c
- the comparator used in this queue, or null
for the natural order.public LongArrayIndirectPriorityQueue(long[] refArray)
refArray
- the reference array.public LongArrayIndirectPriorityQueue(long[] refArray, int[] a, int size, LongComparator c)
The queue returned by this method will be backed by the given array.
refArray
- the reference array.a
- an array of indices into refArray
.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 LongArrayIndirectPriorityQueue(long[] refArray, int[] a, LongComparator c)
The queue returned by this method will be backed by the given array.
refArray
- the reference array.a
- an array of indices into refArray
.c
- the comparator used in this queue, or null
for the natural order.public LongArrayIndirectPriorityQueue(long[] refArray, int[] a, int size)
The queue returned by this method will be backed by the given array.
refArray
- the reference array.a
- an array of indices into refArray
.size
- the number of elements to be included in the queue.public LongArrayIndirectPriorityQueue(long[] refArray, int[] a)
The queue returned by this method will be backed by the given array.
refArray
- the reference array.a
- an array of indices into refArray
.public void enqueue(int x)
Note that for efficiency reasons this method will not throw an exception
when x
is already in the queue. However, the queue state will become
inconsistent and the following behaviour will not be predictable.
enqueue
in interface IndirectPriorityQueue<java.lang.Long>
x
- the element to enqueue.public int dequeue()
IndirectPriorityQueue
dequeue
in interface IndirectPriorityQueue<java.lang.Long>
public int first()
IndirectPriorityQueue
first
in interface IndirectPriorityQueue<java.lang.Long>
public int last()
IndirectPriorityQueue
This default implementation just throws an UnsupportedOperationException
.
last
in interface IndirectPriorityQueue<java.lang.Long>
public void changed()
IndirectPriorityQueue
This default implementation just calls IndirectPriorityQueue.changed(int)
with argument IndirectPriorityQueue.first()
.
changed
in interface IndirectPriorityQueue<java.lang.Long>
public void changed(int index)
Note that the specified element must belong to this queue.
This default implementation just throws an UnsupportedOperationException
.
Note that for efficiency reasons this method will not throw an exception
when index
is not in the queue.
changed
in interface IndirectPriorityQueue<java.lang.Long>
index
- the element that has changed.public void allChanged()
allChanged
in interface IndirectPriorityQueue<java.lang.Long>
public boolean remove(int index)
IndirectPriorityQueue
This default implementation just throws an UnsupportedOperationException
.
remove
in interface IndirectPriorityQueue<java.lang.Long>
index
- the element to be removed.public int front(int[] a)
front
in interface IndirectPriorityQueue<java.lang.Long>
a
- an array whose initial part will be filled with the frnot (must be sized as least as the heap size).public int size()
IndirectPriorityQueue
size
in interface IndirectPriorityQueue<java.lang.Long>
public void clear()
IndirectPriorityQueue
clear
in interface IndirectPriorityQueue<java.lang.Long>
public void trim()
size()
elements.public LongComparator comparator()
LongIndirectPriorityQueue
comparator
in interface IndirectPriorityQueue<java.lang.Long>
comparator
in interface LongIndirectPriorityQueue
IndirectPriorityQueue.comparator()
public java.lang.String toString()
toString
in class java.lang.Object