Class IntArrayList
- All Implemented Interfaces:
IntCollection
,IntIterable
,IntList
,IntStack
,Stack<Integer>
,Serializable
,Cloneable
,Comparable<List<? extends Integer>>
,Iterable<Integer>
,Collection<Integer>
,List<Integer>
,RandomAccess
public class IntArrayList extends AbstractIntList implements RandomAccess, Cloneable, Serializable
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 doubling
its current length), 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:
ArrayList
, Serialized Form
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Nested Class Summary
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.ints.AbstractIntList
AbstractIntList.IntSubList
-
Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_INITIAL_CAPACITY
The initial default capacity of an array list. -
Constructor Summary
Constructors Constructor Description IntArrayList()
Creates a new array list withDEFAULT_INITIAL_CAPACITY
capacity.IntArrayList(int capacity)
Creates a new array list with given capacity.IntArrayList(int[] a)
Creates a new array list and fills it with the elements of a given array.IntArrayList(int[] a, int offset, int length)
Creates a new array list and fills it with the elements of a given array.IntArrayList(IntCollection c)
Creates a new array list and fills it with a given type-specific collection.IntArrayList(IntIterator i)
Creates a new array list and fills it with the elements returned by a type-specific iterator..IntArrayList(IntList l)
Creates a new array list and fills it with a given type-specific list.IntArrayList(Collection<? extends Integer> c)
Creates a new array list and fills it with a given collection.IntArrayList(Iterator<? extends Integer> i)
Creates a new array list and fills it with the elements returned by an iterator.. -
Method Summary
Modifier and Type Method Description boolean
add(int k)
Ensures that this collection contains the specified element (optional operation).void
add(int index, int k)
Inserts the specified element at the specified position in this list (optional operation).boolean
addAll(int index, IntCollection c)
Inserts all of the elements in the specified type-specific collection into this type-specific list at the specified position (optional operation).boolean
addAll(int index, IntList l)
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, int[] a, int offset, int length)
Adds elements to this type-specific list using optimized system calls.void
clear()
IntArrayList
clone()
int
compareTo(IntArrayList l)
Compares this array list to another array list.int[]
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
equals(IntArrayList l)
Compares this type-specific array list to another one.void
getElements(int from, int[] a, int offset, int length)
Copies element of this type-specific list into the given array using optimized system calls.int
getInt(int index)
Returns the element at the specified position in this list.int
indexOf(int 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(int 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.IntListIterator
listIterator(int index)
Returns a type-specific list iterator on the list starting at a given index.static IntArrayList
of(int... init)
Creates an array list using a list of elements.boolean
rem(int k)
Removes a single instance of the specified element from this collection, if it is present (optional operation).boolean
removeAll(IntCollection c)
Remove from this collection all elements in the given type-specific collection.boolean
removeAll(Collection<?> c)
void
removeElements(int from, int to)
Removes elements of this type-specific list using optimized system calls.int
removeInt(int index)
Removes the element at the specified position in this list (optional operation).int
set(int index, int k)
Replaces the element at the specified position in this list with the specified element (optional operation).void
setElements(int index, int[] 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(IntComparator comp)
Sort a list using a type-specific comparator.int[]
toArray(int[] 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.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(IntComparator comp)
Sorts this list using a sort not assured to be stable.static IntArrayList
wrap(int[] a)
Wraps a given array into an array list.static IntArrayList
wrap(int[] a, int length)
Wraps a given array into an array list of given size.Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractIntList
addAll, addAll, addAll, addAll, addElements, compareTo, contains, equals, hashCode, iterator, listIterator, peekInt, popInt, push, subList, topInt, toString
Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractIntCollection
add, contains, containsAll, containsAll, remove, retainAll, retainAll, toIntArray, toIntArray
Methods inherited from class java.util.AbstractCollection
toArray, toArray
Methods inherited from interface java.util.Collection
parallelStream, stream, toArray
Methods inherited from interface it.unimi.dsi.fastutil.ints.IntCollection
containsAll, removeIf, removeIf, retainAll, toIntArray, toIntArray
Methods inherited from interface it.unimi.dsi.fastutil.ints.IntIterable
forEach, forEach
Methods inherited from interface it.unimi.dsi.fastutil.ints.IntList
add, add, contains, get, indexOf, lastIndexOf, remove, remove, set, setElements, setElements, sort, unstableSort
Methods inherited from interface java.util.List
containsAll, replaceAll, retainAll, spliterator, toArray, toArray
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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:
- Constant Field Values
-
-
Constructor Details
-
IntArrayList
public IntArrayList(int capacity)Creates a new array list with given capacity.- Parameters:
capacity
- the initial capacity of the array list (may be 0).
-
IntArrayList
public IntArrayList()Creates a new array list withDEFAULT_INITIAL_CAPACITY
capacity. -
IntArrayList
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.
-
IntArrayList
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.
-
IntArrayList
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.
-
IntArrayList
public IntArrayList(int[] 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.
-
IntArrayList
public IntArrayList(int[] 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.
-
IntArrayList
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.
-
IntArrayList
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 int[] elements()Returns the backing array of this list.- Returns:
- the backing array.
-
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 an array list using a list of elements.- Parameters:
init
- a list of elements that will be used to initialize the list.- Returns:
- a new array list containing the given elements.
-
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.
-
add
public void add(int index, int k)Description copied from class:AbstractIntList
Inserts the specified element at the specified position in this list (optional operation).This implementation always throws an
UnsupportedOperationException
.- Specified by:
add
in interfaceIntList
- Overrides:
add
in classAbstractIntList
- See Also:
List.add(int,Object)
-
add
public boolean add(int k)Description copied from class:AbstractIntList
Ensures that this collection contains the specified element (optional operation).This implementation always throws an
UnsupportedOperationException
.This implementation delegates to the type-specific version of
List.add(int, Object)
.- Specified by:
add
in interfaceIntCollection
- Specified by:
add
in interfaceIntList
- Overrides:
add
in classAbstractIntList
- See Also:
Collection.add(Object)
-
getInt
public int getInt(int index)Description copied from interface:IntList
Returns the element at the specified position in this list.- Specified by:
getInt
in interfaceIntList
- See Also:
List.get(int)
-
indexOf
public int indexOf(int k)Description copied from interface:IntList
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 interfaceIntList
- Overrides:
indexOf
in classAbstractIntList
- See Also:
List.indexOf(Object)
-
lastIndexOf
public int lastIndexOf(int k)Description copied from interface:IntList
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 interfaceIntList
- Overrides:
lastIndexOf
in classAbstractIntList
- See Also:
List.lastIndexOf(Object)
-
removeInt
public int removeInt(int index)Description copied from class:AbstractIntList
Removes the element at the specified position in this list (optional operation).This implementation always throws an
UnsupportedOperationException
.- Specified by:
removeInt
in interfaceIntList
- Overrides:
removeInt
in classAbstractIntList
- See Also:
List.remove(int)
-
rem
public boolean rem(int k)Description copied from class:AbstractIntList
Removes a single instance of the specified element from this collection, if it is present (optional operation).This implementation delegates to
indexOf()
.- Specified by:
rem
in interfaceIntCollection
- Overrides:
rem
in classAbstractIntList
- See Also:
List.remove(Object)
-
set
public int set(int index, int k)Description copied from class:AbstractIntList
Replaces the element at the specified position in this list with the specified element (optional operation).This implementation always throws an
UnsupportedOperationException
.- Specified by:
set
in interfaceIntList
- Overrides:
set
in classAbstractIntList
- See Also:
List.set(int,Object)
-
clear
public void clear()Description copied from class:AbstractIntList
This implementation delegates to
AbstractIntList.removeElements(int, int)
.- Specified by:
clear
in interfaceCollection<Integer>
- Specified by:
clear
in interfaceList<Integer>
- Overrides:
clear
in classAbstractIntList
-
size
public int size()- Specified by:
size
in interfaceCollection<Integer>
- Specified by:
size
in interfaceList<Integer>
- Specified by:
size
in classAbstractCollection<Integer>
-
size
public void size(int size)Description copied from interface:IntList
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 interfaceIntList
- Overrides:
size
in classAbstractIntList
- Parameters:
size
- the new size.
-
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:
ArrayList.trimToSize()
-
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.
-
getElements
public void getElements(int from, int[] a, int offset, int length)Copies element of this type-specific list into the given array using optimized system calls.- Specified by:
getElements
in interfaceIntList
- Overrides:
getElements
in classAbstractIntList
- 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 interfaceIntList
- Overrides:
removeElements
in classAbstractIntList
- Parameters:
from
- the start index (inclusive).to
- the end index (exclusive).
-
addElements
public void addElements(int index, int[] a, int offset, int length)Adds elements to this type-specific list using optimized system calls.- Specified by:
addElements
in interfaceIntList
- Overrides:
addElements
in classAbstractIntList
- 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, int[] a, int offset, int length)Sets elements to this type-specific list using optimized system calls.- Specified by:
setElements
in interfaceIntList
- 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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toArray
public int[] toArray(int[] a)Description copied from interface:IntCollection
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 interfaceIntCollection
- Overrides:
toArray
in classAbstractIntCollection
- 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:
Collection.toArray(Object[])
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addAll
Description copied from interface:IntList
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 interfaceIntList
- Overrides:
addAll
in classAbstractIntList
- See Also:
List.addAll(int,java.util.Collection)
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addAll
Description copied from class:AbstractIntList
Inserts all of the elements in the specified type-specific list into this type-specific list at the specified position (optional operation).This implementation delegates to the type-specific version of
List.addAll(int, Collection)
.- Specified by:
addAll
in interfaceIntList
- Overrides:
addAll
in classAbstractIntList
- See Also:
List.add(int,Object)
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removeAll
Description copied from interface:IntCollection
Remove from this collection all elements in the given type-specific collection.- Specified by:
removeAll
in interfaceIntCollection
- Overrides:
removeAll
in classAbstractIntCollection
- Parameters:
c
- a type-specific collection.- Returns:
true
if this collection changed as a result of the call.- See Also:
Collection.removeAll(Collection)
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removeAll
Description copied from class:AbstractIntCollection
This implementation delegates to the type-specific version if given a type-specific collection, otherwise is uses the implementation from
AbstractCollection
.- Specified by:
removeAll
in interfaceCollection<Integer>
- Specified by:
removeAll
in interfaceList<Integer>
- Overrides:
removeAll
in classAbstractIntCollection
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listIterator
Description copied from class:AbstractIntList
Returns a type-specific list iterator on the list starting at a given index.This implementation is based on the random-access methods.
- Specified by:
listIterator
in interfaceIntList
- Specified by:
listIterator
in interfaceList<Integer>
- Overrides:
listIterator
in classAbstractIntList
- See Also:
List.listIterator(int)
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sort
Description copied from interface:IntList
Sort a list using a type-specific comparator.Pass
null
to sort using natural ordering.- Specified by:
sort
in interfaceIntList
- See Also:
List.sort(java.util.Comparator)
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unstableSort
Description copied from interface:IntList
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 interfaceIntList
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clone
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equals
Compares this type-specific array list to another one.This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.
- Parameters:
l
- a type-specific array list.- Returns:
- true if the argument contains the same elements of this type-specific array list.
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compareTo
Compares this array list to another array list.This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.
- 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.
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