it.unimi.dsi.fastutil.ints
Class IntArrayList

java.lang.Object
  it.unimi.dsi.fastutil.ints.AbstractIntCollection
      it.unimi.dsi.fastutil.ints.AbstractIntList
          it.unimi.dsi.fastutil.ints.IntArrayList

All Implemented Interfaces:

Cloneable, Collection, Comparable, IntCollection, IntList, IntStack, List, RandomAccess, Serializable, Stack

public class IntArrayList

extends AbstractIntList

implements RandomAccess, Cloneable, Serializable

A type-specific array-based list; provides some additional methods that use polymorphism to reduce type juggling.

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 dividing the current length by the golden ratio), 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

Field Summary

static int	DEFAULT_INITIAL_CAPACITY The initial default capacity of an array list.
static long	serialVersionUID

Constructor Summary

IntArrayList()
Creates a new array list with DEFAULT_INITIAL_CAPACITY capacity.

IntArrayList(Collection c)
Creates a new array list and fills it with a given collection.

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(Iterator i)
Creates a new array list and fills it with the elements returned by an iterator..

Method Summary

boolean	add(int k)
void	add(int index, int k)
boolean	addAll(int index, IntCollection c) Delegates to a more generic method.
boolean	addAll(int index, IntList l) Delegates to a more generic method.
boolean	addAll(IntList l) Delegates to a more generic method.
void	addElements(int index, int[] a, int offset, int length) Adds elements to this type-specific list using optimized system calls.
void	clear()
Object	clone()
int	compareTo(IntArrayList l)
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)
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)
int	indexOf(int k)
IntListIterator	intListIterator(int index) Returns a type-specific list iterator on the list starting at a given index.
boolean	isEmpty() Checks whether the stack is empty.
int	lastIndexOf(int k)
boolean	rem(int k) Note that this method should be called remove(), but the clash with the similarly named index-based method in the List interface forces us to use a distinguished name.
void	removeElements(int from, int to) Removes elements of this type-specific list using optimized system calls.
int	removeInt(int index)
int	set(int index, int k)
int	size()
void	size(int size) Sets the size of this list.
int[]	toIntArray(int[] a) Builds a primitive type array containing the items of this collection.
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.
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

add, addAll, addAll, addAll, addElements, compareTo, contains, equals, get, hashCode, indexOf, intIterator, intListIterator, intSubList, lastIndexOf, listIterator, listIterator, peek, peekInt, pop, popInt, push, push, remove, set, subList, top, topInt, toString

Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractIntCollection

add, contains, containsAll, containsAll, iterator, rem, remove, removeAll, removeAll, retainAll, retainAll, toArray, toArray, toArray, toIntArray

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

add, contains, containsAll, iterator, remove, removeAll, retainAll, toArray, toArray

Methods inherited from interface it.unimi.dsi.fastutil.ints.IntCollection

containsAll, removeAll, retainAll, toArray, toIntArray

Field Detail

DEFAULT_INITIAL_CAPACITY

public static final int DEFAULT_INITIAL_CAPACITY

The initial default capacity of an array list.

See Also:

Constant Field Values

serialVersionUID

public static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

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 with DEFAULT_INITIAL_CAPACITY capacity.

IntArrayList

public IntArrayList(Collection c)

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

public IntArrayList(IntCollection c)

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

public IntArrayList(IntList l)

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

public IntArrayList(Iterator i)

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

public IntArrayList(IntIterator i)

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.

Method Detail

elements

public int[] elements()

Returns the backing array of this list.

Returns:

the backing array.

wrap

public static IntArrayList wrap(int[] a,
                                int length)

Wraps a given array into an array list of given size.

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

public static IntArrayList wrap(int[] a)

Wraps a given array into an array list.

Parameters:

a - an array to wrap.

Returns:

a new array list wrapping the given array.

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)

Specified by:

add in interface IntList

Overrides:

add in class AbstractIntList

add

public boolean add(int k)

Specified by:

add in interface IntCollection

Overrides:

add in class AbstractIntCollection

addAll

public boolean addAll(int index,
                      IntCollection c)

Description copied from class: AbstractIntList

Delegates to a more generic method.

Specified by:

addAll in interface IntList

Overrides:

addAll in class AbstractIntList

addAll

public boolean addAll(int index,
                      IntList l)

Description copied from class: AbstractIntList

Delegates to a more generic method.

Specified by:

addAll in interface IntList

Overrides:

addAll in class AbstractIntList

addAll

public boolean addAll(IntList l)

Description copied from class: AbstractIntList

Delegates to a more generic method.

Specified by:

addAll in interface IntList

Overrides:

addAll in class AbstractIntList

getInt

public int getInt(int index)

Specified by:

getInt in interface IntList

See Also:

List.get(int)

indexOf

public int indexOf(int k)

Specified by:

indexOf in interface IntList

Overrides:

indexOf in class AbstractIntList

lastIndexOf

public int lastIndexOf(int k)

Specified by:

lastIndexOf in interface IntList

Overrides:

lastIndexOf in class AbstractIntList

removeInt

public int removeInt(int index)

Specified by:

removeInt in interface IntList

Overrides:

removeInt in class AbstractIntList

rem

public boolean rem(int k)

Description copied from interface: IntCollection

Note that this method should be called remove(), but the clash with the similarly named index-based method in the List interface forces us to use a distinguished name. For simplicity, the set interfaces reinstates remove().

Specified by:

rem in interface IntCollection

Overrides:

rem in class AbstractIntList

set

public int set(int index,
               int k)

Specified by:

set in interface IntList

Overrides:

set in class AbstractIntList

clear

public void clear()

Specified by:

clear in interface List

Overrides:

clear in class AbstractIntCollection

size

public int size()

Specified by:

size in interface List

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 interface IntList

Overrides:

size in class AbstractIntList

isEmpty

public boolean isEmpty()

Description copied from interface: Stack

Checks whether the stack is empty.

Specified by:

isEmpty in interface List

Overrides:

isEmpty in class AbstractIntCollection

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 to n, or if the number of elements is larger than n, this method does nothing. Otherwise, it trims the array length to n.

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 interface IntList

Overrides:

getElements in class AbstractIntList

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.

removeElements

public void removeElements(int from,
                           int to)

Removes elements of this type-specific list using optimized system calls.

Specified by:

removeElements in interface IntList

Overrides:

removeElements in class AbstractIntList

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 interface IntList

Overrides:

addElements in class AbstractIntList

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.

toIntArray

public int[] toIntArray(int[] a)

Description copied from interface: IntCollection

Builds a primitive type array containing the items of this collection.

Specified by:

toIntArray in interface IntCollection

Overrides:

toIntArray in class AbstractIntCollection

intListIterator

public IntListIterator intListIterator(int index)

Description copied from interface: IntList

Returns a type-specific list iterator on the list starting at a given index.

The iterator returned by the List.listIterator() method and by this method are identical; however, using this method you can save a type casting.

Specified by:

intListIterator in interface IntList

See Also:

List.listIterator(int)

clone

public Object clone()

equals

public boolean equals(IntArrayList l)

compareTo

public int compareTo(IntArrayList l)