Class LongArrayList
- All Implemented Interfaces:
LongCollection
,LongIterable
,LongList
,LongStack
,Stack<Long>
,Serializable
,Cloneable
,Comparable<List<? extends Long>>
,Iterable<Long>
,Collection<Long>
,List<Long>
,RandomAccess
This class implements a lightweight, fast, open, optimized, reuse-oriented version of array-based
lists. Instances of this class represent a list with an array that is enlarged as needed when new
entries are created (by increasing its current length by 50%), but is never made smaller
(even on a clear()
). A family of trimming methods lets you control
the size of the backing array; this is particularly useful if you reuse instances of this class.
Range checks are equivalent to those of java.util
's classes, but they are delayed as much
as possible. The backing array is exposed by the elements()
method.
This class implements the bulk methods removeElements()
, addElements()
and
getElements()
using high-performance system calls (e.g.,
System.arraycopy()
) instead of expensive
loops.
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.longs.AbstractLongList
AbstractLongList.LongRandomAccessSubList, AbstractLongList.LongSubList
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Field Summary
Modifier and TypeFieldDescriptionstatic final int
The initial default capacity of an array list. -
Constructor Summary
ConstructorDescriptionCreates a new array list withDEFAULT_INITIAL_CAPACITY
capacity.LongArrayList
(int capacity) Creates a new array list with given capacity.LongArrayList
(long[] a) Creates a new array list and fills it with the elements of a given array.LongArrayList
(long[] a, int offset, int length) Creates a new array list and fills it with the elements of a given array.Creates a new array list and fills it with a given type-specific collection.Creates a new array list and fills it with the elements returned by a type-specific iterator..Creates a new array list and fills it with a given type-specific list.LongArrayList
(Collection<? extends Long> c) Creates a new array list and fills it with a given collection.LongArrayList
(Iterator<? extends Long> i) Creates a new array list and fills it with the elements returned by an iterator.. -
Method Summary
Modifier and TypeMethodDescriptionvoid
add
(int index, long k) Inserts the specified element at the specified position in this list (optional operation).boolean
add
(long k) Ensures that this collection contains the specified element (optional operation).boolean
addAll
(int index, LongCollection c) Inserts all of the elements in the specified type-specific collection into this type-specific list at the specified position (optional operation).boolean
Inserts all of the elements in the specified type-specific list into this type-specific list at the specified position (optional operation).void
addElements
(int index, long[] a, int offset, int length) Adds elements to this type-specific list using optimized system calls.void
clear()
clone()
int
Compares this array list to another array list.int
Compares this list to another object.long[]
elements()
Returns the backing array of this list.void
ensureCapacity
(int capacity) Ensures that this array list can contain the given number of entries without resizing.boolean
Compares this type-specific array list to another one.boolean
void
forEach
(LongConsumer action) Performs the given action for each element of this type-specificIterable
until all elements have been processed or the action throws an exception.void
getElements
(int from, long[] a, int offset, int length) Copies element of this type-specific list into the given array using optimized system calls.long
getLong
(int index) Returns the element at the specified position in this list.int
indexOf
(long k) Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.boolean
isEmpty()
Checks whether the stack is empty.int
lastIndexOf
(long k) Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.listIterator
(int index) Returns a type-specific list iterator on the list starting at a given index.static LongArrayList
of()
Creates a new empty array list.static LongArrayList
of
(long... init) Creates an array list using an array of elements.boolean
rem
(long k) Removes a single instance of the specified element from this collection, if it is present (optional operation).boolean
Remove from this collection all elements in the given type-specific collection.void
removeElements
(int from, int to) Removes elements of this type-specific list using optimized system calls.long
removeLong
(int index) Removes the element at the specified position in this list (optional operation).long
set
(int index, long k) Replaces the element at the specified position in this list with the specified element (optional operation).void
setElements
(int index, long[] a, int offset, int length) Sets elements to this type-specific list using optimized system calls.int
size()
void
size
(int size) Sets the size of this list.void
sort
(LongComparator comp) Sort a list using a type-specific comparator.Returns a type-specific spliterator on the elements of this list.subList
(int from, int to) Returns a type-specific view of the portion of this list from the indexfrom
, inclusive, to the indexto
, exclusive.long[]
toArray
(long[] a) Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.static LongArrayList
toList
(LongStream stream) Collects the result of a primitiveStream
into a new ArrayList.static LongArrayList
toListWithExpectedSize
(LongStream stream, int expectedSize) Collects the result of a primitiveStream
into a new ArrayList, potentially pre-allocated to handle the given size.void
trim()
Trims this array list so that the capacity is equal to the size.void
trim
(int n) Trims the backing array if it is too large.void
unstableSort
(LongComparator comp) Sorts this list using a sort not assured to be stable.static LongArrayList
wrap
(long[] a) Wraps a given array into an array list.static LongArrayList
wrap
(long[] a, int length) Wraps a given array into an array list of given size.Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongList
addAll, addAll, addAll, addElements, contains, hashCode, iterator, listIterator, peekLong, popLong, push, replaceAll, toLongArray, topLong, toString
Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongCollection
add, contains, containsAll, containsAll, forEach, remove, removeAll, removeIf, retainAll, retainAll, toLongArray
Methods inherited from class java.util.AbstractCollection
toArray, toArray
Methods inherited from interface java.util.Collection
toArray
Methods inherited from interface it.unimi.dsi.fastutil.longs.LongCollection
containsAll, longIterator, longParallelStream, longSpliterator, longStream, parallelStream, removeIf, removeIf, removeIf, retainAll, stream, toLongArray
Methods inherited from interface it.unimi.dsi.fastutil.longs.LongIterable
forEach, forEach
Methods inherited from interface it.unimi.dsi.fastutil.longs.LongList
add, add, addAll, contains, get, indexOf, lastIndexOf, remove, remove, replaceAll, replaceAll, set, setElements, setElements, sort, unstableSort
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Field Details
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DEFAULT_INITIAL_CAPACITY
public static final int DEFAULT_INITIAL_CAPACITYThe initial default capacity of an array list.- See Also:
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Constructor Details
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LongArrayList
public LongArrayList(int capacity) Creates a new array list with given capacity.- Parameters:
capacity
- the initial capacity of the array list (may be 0).
-
LongArrayList
public LongArrayList()Creates a new array list withDEFAULT_INITIAL_CAPACITY
capacity. -
LongArrayList
Creates a new array list and fills it with a given collection.- Parameters:
c
- a collection that will be used to fill the array list.
-
LongArrayList
Creates a new array list and fills it with a given type-specific collection.- Parameters:
c
- a type-specific collection that will be used to fill the array list.
-
LongArrayList
Creates a new array list and fills it with a given type-specific list.- Parameters:
l
- a type-specific list that will be used to fill the array list.
-
LongArrayList
public LongArrayList(long[] a) Creates a new array list and fills it with the elements of a given array.- Parameters:
a
- an array whose elements will be used to fill the array list.
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LongArrayList
public LongArrayList(long[] a, int offset, int length) Creates a new array list and fills it with the elements of a given array.- Parameters:
a
- an array whose elements will be used to fill the array list.offset
- the first element to use.length
- the number of elements to use.
-
LongArrayList
Creates a new array list and fills it with the elements returned by an iterator..- Parameters:
i
- an iterator whose returned elements will fill the array list.
-
LongArrayList
Creates a new array list and fills it with the elements returned by a type-specific iterator..- Parameters:
i
- a type-specific iterator whose returned elements will fill the array list.
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Method Details
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elements
public long[] elements()Returns the backing array of this list.- Returns:
- the backing array.
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wrap
Wraps a given array into an array list of given size.Note it is guaranteed that the type of the array returned by
elements()
will be the same (see the comments in the class documentation).- Parameters:
a
- an array to wrap.length
- the length of the resulting array list.- Returns:
- a new array list of the given size, wrapping the given array.
-
wrap
Wraps a given array into an array list.Note it is guaranteed that the type of the array returned by
elements()
will be the same (see the comments in the class documentation).- Parameters:
a
- an array to wrap.- Returns:
- a new array list wrapping the given array.
-
of
Creates a new empty array list.- Returns:
- a new empty array list.
-
of
Creates an array list using an array of elements.- Parameters:
init
- a the array the will become the new backing array of the array list.- Returns:
- a new array list backed by the given array.
- See Also:
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toList
Collects the result of a primitiveStream
into a new ArrayList.This method performs a terminal operation on the given
Stream
- API Notes:
- Taking a primitive stream instead of returning something like a
Collector
is necessary because there is no primitiveCollector
equivalent in the Java API.
-
toListWithExpectedSize
Collects the result of a primitiveStream
into a new ArrayList, potentially pre-allocated to handle the given size.This method performs a terminal operation on the given
Stream
- API Notes:
- Taking a primitive stream instead returning something like a
Collector
is necessary because there is no primitiveCollector
equivalent in the Java API.
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ensureCapacity
public void ensureCapacity(int capacity) Ensures that this array list can contain the given number of entries without resizing.- Parameters:
capacity
- the new minimum capacity for this array list.
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add
public void add(int index, long k) Description copied from class:AbstractLongList
Inserts the specified element at the specified position in this list (optional operation).- Specified by:
add
in interfaceLongList
- Overrides:
add
in classAbstractLongList
- See Also:
-
add
public boolean add(long k) Description copied from class:AbstractLongList
Ensures that this collection contains the specified element (optional operation).- Specified by:
add
in interfaceLongCollection
- Specified by:
add
in interfaceLongList
- Overrides:
add
in classAbstractLongList
- See Also:
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getLong
public long getLong(int index) Description copied from interface:LongList
Returns the element at the specified position in this list. -
indexOf
public int indexOf(long k) Description copied from interface:LongList
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.- Specified by:
indexOf
in interfaceLongList
- Overrides:
indexOf
in classAbstractLongList
- See Also:
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lastIndexOf
public int lastIndexOf(long k) Description copied from interface:LongList
Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.- Specified by:
lastIndexOf
in interfaceLongList
- Overrides:
lastIndexOf
in classAbstractLongList
- See Also:
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removeLong
public long removeLong(int index) Description copied from class:AbstractLongList
Removes the element at the specified position in this list (optional operation).- Specified by:
removeLong
in interfaceLongList
- Overrides:
removeLong
in classAbstractLongList
- See Also:
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rem
public boolean rem(long k) Description copied from class:AbstractLongList
Removes a single instance of the specified element from this collection, if it is present (optional operation).- Specified by:
rem
in interfaceLongCollection
- Overrides:
rem
in classAbstractLongList
- See Also:
-
set
public long set(int index, long k) Description copied from class:AbstractLongList
Replaces the element at the specified position in this list with the specified element (optional operation).- Specified by:
set
in interfaceLongList
- Overrides:
set
in classAbstractLongList
- See Also:
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clear
public void clear()Description copied from class:AbstractLongList
- Specified by:
clear
in interfaceCollection<Long>
- Specified by:
clear
in interfaceList<Long>
- Overrides:
clear
in classAbstractLongList
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size
public int size()- Specified by:
size
in interfaceCollection<Long>
- Specified by:
size
in interfaceList<Long>
- Specified by:
size
in classAbstractCollection<Long>
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size
public void size(int size) Description copied from interface:LongList
Sets the size of this list.If the specified size is smaller than the current size, the last elements are discarded. Otherwise, they are filled with 0/
null
/false
.- Specified by:
size
in interfaceLongList
- Overrides:
size
in classAbstractLongList
- Parameters:
size
- the new size.
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isEmpty
public boolean isEmpty()Description copied from interface:Stack
Checks whether the stack is empty. -
trim
public void trim()Trims this array list so that the capacity is equal to the size.- See Also:
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trim
public void trim(int n) Trims the backing array if it is too large. If the current array length is smaller than or equal ton
, this method does nothing. Otherwise, it trims the array length to the maximum betweenn
andsize()
.This method is useful when reusing lists. Clearing a list leaves the array length untouched. If you are reusing a list many times, you can call this method with a typical size to avoid keeping around a very large array just because of a few large transient lists.
- Parameters:
n
- the threshold for the trimming.
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subList
Description copied from interface:LongList
Returns a type-specific view of the portion of this list from the indexfrom
, inclusive, to the indexto
, exclusive. -
getElements
public void getElements(int from, long[] a, int offset, int length) Copies element of this type-specific list into the given array using optimized system calls.- Specified by:
getElements
in interfaceLongList
- Overrides:
getElements
in classAbstractLongList
- Parameters:
from
- the start index (inclusive).a
- the destination array.offset
- the offset into the destination array where to store the first element copied.length
- the number of elements to be copied.
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removeElements
public void removeElements(int from, int to) Removes elements of this type-specific list using optimized system calls.- Specified by:
removeElements
in interfaceLongList
- Overrides:
removeElements
in classAbstractLongList
- Parameters:
from
- the start index (inclusive).to
- the end index (exclusive).
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addElements
public void addElements(int index, long[] a, int offset, int length) Adds elements to this type-specific list using optimized system calls.- Specified by:
addElements
in interfaceLongList
- Overrides:
addElements
in classAbstractLongList
- Parameters:
index
- the index at which to add elements.a
- the array containing the elements.offset
- the offset of the first element to add.length
- the number of elements to add.
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setElements
public void setElements(int index, long[] a, int offset, int length) Sets elements to this type-specific list using optimized system calls.- Specified by:
setElements
in interfaceLongList
- Overrides:
setElements
in classAbstractLongList
- Parameters:
index
- the index at which to start setting elements.a
- the array containing the elements.offset
- the offset of the first element to add.length
- the number of elements to add.
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forEach
Description copied from class:AbstractLongList
Performs the given action for each element of this type-specificIterable
until all elements have been processed or the action throws an exception.- Specified by:
forEach
in interfaceLongIterable
- Overrides:
forEach
in classAbstractLongList
- Parameters:
action
- the action to be performed for each element.- See Also:
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addAll
Description copied from interface:LongList
Inserts all of the elements in the specified type-specific collection into this type-specific list at the specified position (optional operation).- Specified by:
addAll
in interfaceLongList
- Overrides:
addAll
in classAbstractLongList
- See Also:
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addAll
Description copied from interface:LongList
Inserts all of the elements in the specified type-specific list into this type-specific list at the specified position (optional operation). -
removeAll
Description copied from interface:LongCollection
Remove from this collection all elements in the given type-specific collection.- Specified by:
removeAll
in interfaceLongCollection
- Overrides:
removeAll
in classAbstractLongCollection
- Parameters:
c
- a type-specific collection.- Returns:
true
if this collection changed as a result of the call.- See Also:
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toArray
public long[] toArray(long[] a) Description copied from interface:LongCollection
Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.Note that, contrarily to
Collection.toArray(Object[])
, this methods just writes all elements of this collection: no special value will be added after the last one.- Specified by:
toArray
in interfaceLongCollection
- Overrides:
toArray
in classAbstractLongList
- Parameters:
a
- if this array is big enough, it will be used to store this collection.- Returns:
- a primitive type array containing the items of this collection.
- See Also:
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listIterator
Description copied from class:AbstractLongList
Returns a type-specific list iterator on the list starting at a given index.- Specified by:
listIterator
in interfaceList<Long>
- Specified by:
listIterator
in interfaceLongList
- Overrides:
listIterator
in classAbstractLongList
- See Also:
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spliterator
Returns a type-specific spliterator on the elements of this list.List spliterators must report at least
Spliterator.SIZED
andSpliterator.ORDERED
.See
List.spliterator()
for more documentation on the requirements of the returned spliterator.The returned spliterator is late-binding; it will track structural changes after the current index, up until the first
trySplit()
, at which point the maximum index will be fixed.
Structural changes before the current index or after the firsttrySplit()
will result in unspecified behavior.- Specified by:
spliterator
in interfaceCollection<Long>
- Specified by:
spliterator
in interfaceIterable<Long>
- Specified by:
spliterator
in interfaceList<Long>
- Specified by:
spliterator
in interfaceLongCollection
- Specified by:
spliterator
in interfaceLongIterable
- Specified by:
spliterator
in interfaceLongList
- Returns:
- a type-specific spliterator on the elements of this collection.
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sort
Description copied from interface:LongList
Sort a list using a type-specific comparator.Pass
null
to sort using natural ordering. -
unstableSort
Description copied from interface:LongList
Sorts this list using a sort not assured to be stable.Pass
null
to sort using natural ordering.This differs from
List.sort(java.util.Comparator)
in that the results are not assured to be stable, but may be a bit faster.Unless a subclass specifies otherwise, the results of the method if the list is concurrently modified during the sort are unspecified.
- Specified by:
unstableSort
in interfaceLongList
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clone
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equals
Compares this type-specific array list to another one.- Parameters:
l
- a type-specific array list.- Returns:
- true if the argument contains the same elements of this type-specific array list.
- API Notes:
- This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.
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equals
- Specified by:
equals
in interfaceCollection<Long>
- Specified by:
equals
in interfaceList<Long>
- Overrides:
equals
in classAbstractLongList
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compareTo
Compares this array list to another array list.- Parameters:
l
- an array list.- Returns:
- a negative integer, zero, or a positive integer as this list is lexicographically less than, equal to, or greater than the argument.
- API Notes:
- This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.
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compareTo
Description copied from class:AbstractLongList
Compares this list to another object. If the argument is aList
, this method performs a lexicographical comparison; otherwise, it throws aClassCastException
.- Specified by:
compareTo
in interfaceComparable<List<? extends Long>>
- Overrides:
compareTo
in classAbstractLongList
- Parameters:
l
- a list.- Returns:
- if the argument is a
List
, a negative integer, zero, or a positive integer as this list is lexicographically less than, equal to, or greater than the argument.
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