IndirectPriorityQueue (fastutil 6.4.1 API)

All Known Subinterfaces:

ByteIndirectPriorityQueue, CharIndirectPriorityQueue, DoubleIndirectPriorityQueue, FloatIndirectPriorityQueue, IntIndirectPriorityQueue, LongIndirectPriorityQueue, ShortIndirectPriorityQueue

All Known Implementing Classes:

AbstractIndirectPriorityQueue, ByteArrayIndirectPriorityQueue, ByteHeapIndirectPriorityQueue, ByteHeapSemiIndirectPriorityQueue, CharArrayIndirectPriorityQueue, CharHeapIndirectPriorityQueue, CharHeapSemiIndirectPriorityQueue, DoubleArrayIndirectPriorityQueue, DoubleHeapIndirectPriorityQueue, DoubleHeapSemiIndirectPriorityQueue, FloatArrayIndirectPriorityQueue, FloatHeapIndirectPriorityQueue, FloatHeapSemiIndirectPriorityQueue, IndirectPriorityQueues.EmptyIndirectPriorityQueue, IndirectPriorityQueues.SynchronizedIndirectPriorityQueue, IntArrayIndirectPriorityQueue, IntHeapIndirectPriorityQueue, IntHeapSemiIndirectPriorityQueue, LongArrayIndirectPriorityQueue, LongHeapIndirectPriorityQueue, LongHeapSemiIndirectPriorityQueue, ObjectArrayIndirectPriorityQueue, ObjectHeapIndirectPriorityQueue, ObjectHeapSemiIndirectPriorityQueue, ShortArrayIndirectPriorityQueue, ShortHeapIndirectPriorityQueue, ShortHeapSemiIndirectPriorityQueue
```
public interface IndirectPriorityQueue<K>
```
An indirect priority queue.
An indirect priority queue provides a way to enqueue by index elements taken from a given reference list, and to dequeue them in some specified order. Elements that are smaller in the specified order are dequeued first. It is also possible to get the index of the first element, that is, the index that would be dequeued next.
Additionally, the queue may provide a method to peek at the index of the element that would be dequeued last.
The reference list should not change during queue operations (or, more precisely, the relative order of the elements corresponding to indices in the queue should not change). Nonetheless, some implementations may give the caller a way to notify the queue that the first element has changed its relative position in the order.
Optionally, an indirect priority queue may even provide methods to notify the change of any element of the reference list, to check the presence of an index in the queue, and to remove an index from the queue. It may even allow to notify that all elements have changed.
It is always possible to enqueue two distinct indices corresponding to equal elements of the reference list. However, depending on the implementation, it may or may not be possible to enqueue twice the same index.
Note that all element manipulation happens via indices.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`allChanged()` Notifies this queue that the all elements have changed (optional operation).
`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.
`Comparator<? super K>`	`comparator()` Returns the comparator associated with this queue, or `null` if it uses its elements' natural ordering.
`boolean`	`contains(int index)` Checks whether a given index belongs to this queue (optional operation).
`int`	`dequeue()` Dequeues the first element from this queue.
`void`	`enqueue(int index)` Enqueues a new element.
`int`	`first()` Returns the first element of this queue.
`int`	`front(int[] a)` Retrieves the front of this queue in a given array (optional operation).
`boolean`	`isEmpty()` Checks whether this queue is empty.
`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.

- Method Detail
  - enqueue
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void enqueue(int index)
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    Enqueues a new element.
    
    Parameters:
    index - the element to enqueue..
  - dequeue
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int dequeue()
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    Dequeues the first element from this queue.
    
    Returns:
    the dequeued element.
    
    Throws:
    
    NoSuchElementException - if this queue is empty.
  - isEmpty
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boolean isEmpty()
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    Checks whether this queue is empty.
    
    Returns:
    true if this queue is empty.
  - size
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int size()
```
    Returns the number of elements in this queue.
    
    Returns:
    the number of elements in this queue.
  - clear
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void clear()
```
    Removes all elements from this queue.
  - first
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int first()
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    Returns the first element of this queue.
    
    Returns:
    the first element.
    
    Throws:
    
    NoSuchElementException - if this queue is empty.
  - last
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int last()
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    Returns the last element of this queue, that is, the element the would be dequeued last (optional operation).
    
    Returns:
    the last element.
    
    Throws:
    
    NoSuchElementException - if this queue is empty.
  - changed
```
void changed()
```
    Notifies this queue that the first element has changed (optional operation).
  - comparator
```
Comparator<? super K> comparator()
```
    Returns the comparator associated with this queue, or null if it uses its elements' natural ordering.
    
    Returns:
    the comparator associated with this sorted set, or null if it uses its elements' natural ordering.
  - changed
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void changed(int index)
```
    Notifies this queue that the specified element has changed (optional operation).
    Note that the specified element must belong to this queue.
    
    Parameters:
    index - the element that has changed.
    
    Throws:
    
    NoSuchElementException - if the specified element is not in this queue.
  - allChanged
```
void allChanged()
```
    Notifies this queue that the all elements have changed (optional operation).
  - contains
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boolean contains(int index)
```
    Checks whether a given index belongs to this queue (optional operation).
    
    Returns:
    true if the specified index belongs to this queue.
  - remove
```
boolean remove(int index)
```
    Removes the specified element from this queue (optional operation).
    
    Parameters:
    index - the element to be removed.
    
    Returns:
    true if the index was in the queue.
  - front
```
int front(int[] a)
```
    Retrieves the front of this queue in a given array (optional operation).
    The front of an indirect queue is the set of indices whose associated elements in the reference array are equal to the element associated to the first index. These indices can be always obtain by dequeueing, but this method should retrieve efficiently such indices in the given array without modifying the state of this queue.
    
    Parameters:
    a - an array large enough to hold the front (e.g., at least long as the reference array).
    
    Returns:
    the number of elements actually written (starting from the first position of a).

Interface IndirectPriorityQueue<K>

Method Summary

Method Detail

enqueue

dequeue

isEmpty

size

clear

first

last

changed

comparator

changed

allChanged

contains

remove

front