Package it.unimi.dsi.fastutil.chars
Class CharArrayFIFOQueue
- java.lang.Object
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- it.unimi.dsi.fastutil.chars.CharArrayFIFOQueue
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- All Implemented Interfaces:
CharPriorityQueue
,PriorityQueue<java.lang.Character>
,java.io.Serializable
public class CharArrayFIFOQueue extends java.lang.Object implements CharPriorityQueue, java.io.Serializable
A type-specific array-based FIFO queue, supporting also deque operations.Instances of this class represent a FIFO queue using a backing array in a circular way. The array is enlarged and shrunk as needed. You can use the
trim()
method to reduce its memory usage, if necessary.This class provides additional methods that implement a deque (double-ended queue).
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static int
INITIAL_CAPACITY
The standard initial capacity of a queue.
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Constructor Summary
Constructors Constructor Description CharArrayFIFOQueue()
Creates a new empty queue with standard initial capacity.CharArrayFIFOQueue(int capacity)
Creates a new empty queue with given capacity.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Removes all elements from this queue.CharComparator
comparator()
Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.char
dequeueChar()
Dequeues the first element from the queue.char
dequeueLastChar()
Dequeues the last element from the queue.void
enqueue(char x)
Enqueues a new element.void
enqueueFirst(char x)
Enqueues a new element as the first element (in dequeuing order) of the queue.char
firstChar()
Returns the first element of the queue.char
lastChar()
Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).int
size()
Returns the number of elements in this queue.void
trim()
Trims the queue to the smallest possible size.-
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface it.unimi.dsi.fastutil.chars.CharPriorityQueue
dequeue, enqueue, first, last
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Methods inherited from interface it.unimi.dsi.fastutil.PriorityQueue
changed, isEmpty
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Field Detail
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INITIAL_CAPACITY
public static final int INITIAL_CAPACITY
The standard initial capacity of a queue.- See Also:
- Constant Field Values
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Constructor Detail
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CharArrayFIFOQueue
public CharArrayFIFOQueue(int capacity)
Creates a new empty queue with given capacity.- Parameters:
capacity
- the initial capacity of this queue.
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CharArrayFIFOQueue
public CharArrayFIFOQueue()
Creates a new empty queue with standard initial capacity.
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Method Detail
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comparator
public CharComparator comparator()
Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.Note that this specification strengthens the one given in
PriorityQueue.comparator()
.This implementation returns
null
(FIFO queues have no comparator).- Specified by:
comparator
in interfaceCharPriorityQueue
- Specified by:
comparator
in interfacePriorityQueue<java.lang.Character>
- Returns:
- the comparator associated with this priority queue.
- See Also:
PriorityQueue.comparator()
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dequeueChar
public char dequeueChar()
Description copied from interface:CharPriorityQueue
Dequeues the first element from the queue.- Specified by:
dequeueChar
in interfaceCharPriorityQueue
- Returns:
- the dequeued element.
- See Also:
CharPriorityQueue.dequeue()
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dequeueLastChar
public char dequeueLastChar()
Dequeues the last element from the queue.- Returns:
- the dequeued element.
- Throws:
java.util.NoSuchElementException
- if the queue is empty.
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enqueue
public void enqueue(char x)
Description copied from interface:CharPriorityQueue
Enqueues a new element.- Specified by:
enqueue
in interfaceCharPriorityQueue
- Parameters:
x
- the element to enqueue.- See Also:
PriorityQueue.enqueue(Object)
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enqueueFirst
public void enqueueFirst(char x)
Enqueues a new element as the first element (in dequeuing order) of the queue.- Parameters:
x
- the element to enqueue.
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firstChar
public char firstChar()
Description copied from interface:CharPriorityQueue
Returns the first element of the queue.- Specified by:
firstChar
in interfaceCharPriorityQueue
- Returns:
- the first element.
- See Also:
CharPriorityQueue.first()
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lastChar
public char lastChar()
Description copied from interface:CharPriorityQueue
Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).This default implementation just throws an
UnsupportedOperationException
.- Specified by:
lastChar
in interfaceCharPriorityQueue
- Returns:
- the last element.
- See Also:
CharPriorityQueue.last()
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clear
public void clear()
Description copied from interface:PriorityQueue
Removes all elements from this queue.- Specified by:
clear
in interfacePriorityQueue<java.lang.Character>
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trim
public void trim()
Trims the queue to the smallest possible size.
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size
public int size()
Description copied from interface:PriorityQueue
Returns the number of elements in this queue.- Specified by:
size
in interfacePriorityQueue<java.lang.Character>
- Returns:
- the number of elements in this queue.
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