Class CharHeapIndirectPriorityQueue
- All Implemented Interfaces:
CharIndirectPriorityQueue
,IndirectPriorityQueue<Character>
Instances of this class use an additional inversion array, of the same length of the
reference array, to keep track of the heap position containing a given element of the reference
array. The priority queue is represented using a heap. The heap is enlarged as needed, but it is
never shrunk. Use the CharHeapSemiIndirectPriorityQueue.trim()
method to reduce its size, if necessary.
- Implementation Specification:
- This implementation does not allow one to enqueue several times the same index.
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Constructor Summary
ConstructorDescriptionCharHeapIndirectPriorityQueue
(char[] refArray) Creates a new empty queue with capacity equal to the length of the reference array and using the natural order.CharHeapIndirectPriorityQueue
(char[] refArray, int capacity) Creates a new empty queue with a given capacity and using the natural order.CharHeapIndirectPriorityQueue
(char[] refArray, int[] a) Wraps a given array in a queue using the natural order.CharHeapIndirectPriorityQueue
(char[] refArray, int[] a, int size) Wraps a given array in a queue using the natural order.CharHeapIndirectPriorityQueue
(char[] refArray, int[] a, int size, CharComparator c) Wraps a given array in a queue using a given comparator.CharHeapIndirectPriorityQueue
(char[] refArray, int[] a, CharComparator c) Wraps a given array in a queue using a given comparator.CharHeapIndirectPriorityQueue
(char[] refArray, int capacity, CharComparator c) Creates a new empty queue with a given capacity and comparator.CharHeapIndirectPriorityQueue
(char[] refArray, CharComparator c) Creates a new empty queue with capacity equal to the length of the reference array and a given comparator. -
Method Summary
Modifier and TypeMethodDescriptionvoid
Rebuilds this queue in a bottom-up fashion (in linear time).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.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 x) Enqueues a new element.boolean
remove
(int index) Removes the specified element from this queue (optional operation).Methods inherited from class it.unimi.dsi.fastutil.chars.CharHeapSemiIndirectPriorityQueue
comparator, first, front, size, toString, trim
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface it.unimi.dsi.fastutil.IndirectPriorityQueue
isEmpty, last
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Constructor Details
-
CharHeapIndirectPriorityQueue
Creates a new empty queue with a given capacity and comparator.- Parameters:
refArray
- the reference array.capacity
- the initial capacity of this queue.c
- the comparator used in this queue, ornull
for the natural order.
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CharHeapIndirectPriorityQueue
public CharHeapIndirectPriorityQueue(char[] refArray, int capacity) Creates a new empty queue with a given capacity and using the natural order.- Parameters:
refArray
- the reference array.capacity
- the initial capacity of this queue.
-
CharHeapIndirectPriorityQueue
Creates a new empty queue with capacity equal to the length of the reference array and a given comparator.- Parameters:
refArray
- the reference array.c
- the comparator used in this queue, ornull
for the natural order.
-
CharHeapIndirectPriorityQueue
public CharHeapIndirectPriorityQueue(char[] refArray) Creates a new empty queue with capacity equal to the length of the reference array and using the natural order.- Parameters:
refArray
- the reference array.
-
CharHeapIndirectPriorityQueue
Wraps a given array in a queue using a given comparator.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 ofa
one by one).- Parameters:
refArray
- the reference array.a
- an array of indices intorefArray
.size
- the number of elements to be included in the queue.c
- the comparator used in this queue, ornull
for the natural order.
-
CharHeapIndirectPriorityQueue
Wraps a given array in a queue using a given comparator.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).- Parameters:
refArray
- the reference array.a
- an array of indices intorefArray
.c
- the comparator used in this queue, ornull
for the natural order.
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CharHeapIndirectPriorityQueue
public CharHeapIndirectPriorityQueue(char[] refArray, int[] a, int size) Wraps a given array in a queue using the natural order.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 ofa
one by one).- Parameters:
refArray
- the reference array.a
- an array of indices intorefArray
.size
- the number of elements to be included in the queue.
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CharHeapIndirectPriorityQueue
public CharHeapIndirectPriorityQueue(char[] refArray, int[] a) Wraps a given array in a queue using the natural order.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).- Parameters:
refArray
- the reference array.a
- an array of indices intorefArray
.
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Method Details
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enqueue
public void enqueue(int x) Description copied from interface:IndirectPriorityQueue
Enqueues a new element.- Specified by:
enqueue
in interfaceIndirectPriorityQueue<Character>
- Overrides:
enqueue
in classCharHeapSemiIndirectPriorityQueue
- Parameters:
x
- the element to enqueue.
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contains
public boolean contains(int index) Description copied from interface:IndirectPriorityQueue
Checks whether a given index belongs to this queue (optional operation).This default implementation just throws an
UnsupportedOperationException
.- Parameters:
index
- an index possibly in the queue.- Returns:
- true if the specified index belongs to this queue.
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dequeue
public int dequeue()Description copied from interface:IndirectPriorityQueue
Dequeues the first element from this queue.- Specified by:
dequeue
in interfaceIndirectPriorityQueue<Character>
- Overrides:
dequeue
in classCharHeapSemiIndirectPriorityQueue
- Returns:
- the dequeued element.
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changed
public void changed()Description copied from class:CharHeapSemiIndirectPriorityQueue
Notifies this queue that the first element has changed (optional operation).This default implementation just calls
IndirectPriorityQueue.changed(int)
with argumentIndirectPriorityQueue.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.
- Specified by:
changed
in interfaceIndirectPriorityQueue<Character>
- Overrides:
changed
in classCharHeapSemiIndirectPriorityQueue
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changed
public void changed(int index) Description copied from interface:IndirectPriorityQueue
Notifies this queue that the specified element has changed (optional operation).Note that the specified element must belong to this queue.
This default implementation just throws an
UnsupportedOperationException
.- Parameters:
index
- the element that has changed.
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allChanged
public void allChanged()Rebuilds this queue in a bottom-up fashion (in linear time).- Specified by:
allChanged
in interfaceIndirectPriorityQueue<Character>
- Overrides:
allChanged
in classCharHeapSemiIndirectPriorityQueue
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remove
public boolean remove(int index) Description copied from interface:IndirectPriorityQueue
Removes the specified element from this queue (optional operation).This default implementation just throws an
UnsupportedOperationException
.- Parameters:
index
- the element to be removed.- Returns:
- true if the index was in the queue.
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clear
public void clear()Description copied from interface:IndirectPriorityQueue
Removes all elements from this queue.- Specified by:
clear
in interfaceIndirectPriorityQueue<Character>
- Overrides:
clear
in classCharHeapSemiIndirectPriorityQueue
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