public class IntHeapSemiIndirectPriorityQueue extends java.lang.Object implements IntIndirectPriorityQueue
Instances of this class use as reference list a reference array,
which must be provided to each constructor. The priority queue is represented
using a heap. The heap is enlarged as needed, but it is never shrunk. Use the
trim() method to reduce its size, if necessary.
This implementation allows one to enqueue several time the same index, but
you must be careful when calling changed().
| Constructor and Description |
|---|
IntHeapSemiIndirectPriorityQueue(int[] refArray)
Creates a new empty queue with capacity equal to the length of the reference
array and using the natural order.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int capacity)
Creates a new empty queue with given capacity and using the natural order.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a)
Wraps a given array in a queue using the natural order.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a,
int size)
Wraps a given array in a queue using the natural order.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a,
IntComparator c)
Wraps a given array in a queue using a given comparator.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a,
int size,
IntComparator c)
Wraps a given array in a queue using a given comparator.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
IntComparator c)
Creates a new empty queue with capacity equal to the length of the reference
array and a given comparator.
|
IntHeapSemiIndirectPriorityQueue(int[] refArray,
int capacity,
IntComparator c)
Creates a new empty queue without elements with a given capacity and
comparator.
|
| Modifier and Type | Method and Description |
|---|---|
void |
allChanged()
Rebuilds this heap in a bottom-up fashion (in linear time).
|
void |
changed()
Notifies this queue that the first element has changed (optional operation).
|
void |
clear()
Removes all elements from this queue.
|
IntComparator |
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 |
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. |
public IntHeapSemiIndirectPriorityQueue(int[] refArray,
int capacity,
IntComparator 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 IntHeapSemiIndirectPriorityQueue(int[] refArray,
int capacity)
refArray - the reference array.capacity - the initial capacity of this queue.public IntHeapSemiIndirectPriorityQueue(int[] refArray,
IntComparator c)
refArray - the reference array.c - the comparator used in this queue, or null for the natural
order.public IntHeapSemiIndirectPriorityQueue(int[] refArray)
refArray - the reference array.public IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a,
int size,
IntComparator 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).
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 IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] a,
IntComparator 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).
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 IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] 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).
refArray - the reference array.a - an array of indices into refArray.size - the number of elements to be included in the queue.public IntHeapSemiIndirectPriorityQueue(int[] refArray,
int[] 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).
refArray - the reference array.a - an array of indices into refArray.public void enqueue(int x)
IndirectPriorityQueueenqueue in interface IndirectPriorityQueue<java.lang.Integer>x - the element to enqueue.public int dequeue()
IndirectPriorityQueuedequeue in interface IndirectPriorityQueue<java.lang.Integer>public int first()
IndirectPriorityQueuefirst in interface IndirectPriorityQueue<java.lang.Integer>public void changed()
This default implementation just calls IndirectPriorityQueue.changed(int) with argument IndirectPriorityQueue.first().
The caller must guarantee that when this method is called the index of the first element appears just once in the queue. Failure to do so will bring the queue in an inconsistent state, and will cause unpredictable behaviour.
changed in interface IndirectPriorityQueue<java.lang.Integer>public void allChanged()
allChanged in interface IndirectPriorityQueue<java.lang.Integer>public int size()
IndirectPriorityQueuesize in interface IndirectPriorityQueue<java.lang.Integer>public void clear()
IndirectPriorityQueueclear in interface IndirectPriorityQueue<java.lang.Integer>public void trim()
size() elements.public IntComparator comparator()
IntIndirectPriorityQueue
Note that this specification strengthens the one given in
IndirectPriorityQueue.
comparator in interface IndirectPriorityQueue<java.lang.Integer>comparator in interface IntIndirectPriorityQueueIndirectPriorityQueue.comparator()public int front(int[] a)
front in interface IndirectPriorityQueue<java.lang.Integer>a - an array whose initial part will be filled with the frnot (must be
sized as least as the heap size).public java.lang.String toString()
toString in class java.lang.Object