java.util
Class TreeSet
- Cloneable, Collection, Serializable, Set, SortedSet
This class provides a TreeMap-backed implementation of the SortedSet
interface. The elements will be sorted according to their
natural
order, or according to the provided
Comparator
.
Most operations are O(log n), but there is so much overhead that this
makes small sets expensive. Note that the ordering must be
consistent
with equals to correctly implement the Set interface. If this
condition is violated, the set is still well-behaved, but you may have
suprising results when comparing it to other sets.
This implementation is not synchronized. If you need to share this between
multiple threads, do something like:
SortedSet s
= Collections.synchronizedSortedSet(new TreeSet(...));
The iterators are
fail-fast, meaning that any structural
modification, except for
remove()
called on the iterator
itself, cause the iterator to throw a
ConcurrentModificationException
rather than exhibit
non-deterministic behavior.
TreeSet() - Construct a new TreeSet whose backing TreeMap using the "natural"
ordering of keys.
|
TreeSet(Collection collection) - Construct a new TreeSet whose backing TreeMap uses the "natural"
orering of the keys and which contains all of the elements in the
supplied Collection.
|
TreeSet(Comparator comparator) - Construct a new TreeSet whose backing TreeMap uses the supplied
Comparator.
|
TreeSet(SortedSet sortedSet) - Construct a new TreeSet, using the same key ordering as the supplied
SortedSet and containing all of the elements in the supplied SortedSet.
|
boolean | add(Object obj) - Adds the spplied Object to the Set if it is not already in the Set;
returns true if the element is added, false otherwise.
|
boolean | addAll(Collection c) - Adds all of the elements in the supplied Collection to this TreeSet.
|
void | clear() - Removes all elements in this Set.
|
Object | clone() - Returns a shallow copy of this Set.
|
Comparator | comparator() - Returns this Set's comparator.
|
boolean | contains(Object obj) - Returns true if this Set contains the supplied Object, false otherwise.
|
Object | first() - Returns the first (by order) element in this Set.
|
SortedSet | headSet(Object to) - Returns a view of this Set including all elements less than
to .
|
boolean | isEmpty() - Returns true if this Set has size 0, false otherwise.
|
Iterator | iterator() - Returns in Iterator over the elements in this TreeSet, which traverses
in ascending order.
|
Object | last() - Returns the last (by order) element in this Set.
|
boolean | remove(Object obj) - If the supplied Object is in this Set, it is removed, and true is
returned; otherwise, false is returned.
|
int | size() - Returns the number of elements in this Set
|
SortedSet | subSet(Object from, Object to) - Returns a view of this Set including all elements greater or equal to
from and less than to (a half-open interval).
|
SortedSet | tailSet(Object from) - Returns a view of this Set including all elements greater or equal to
from .
|
add , addAll , clear , contains , containsAll , isEmpty , iterator , remove , removeAll , retainAll , size , toArray , toArray , toString |
clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
TreeSet
public TreeSet()
Construct a new TreeSet whose backing TreeMap using the "natural"
ordering of keys. Elements that are not mutually comparable will cause
ClassCastExceptions down the road.
TreeSet
public TreeSet(Collection collection)
Construct a new TreeSet whose backing TreeMap uses the "natural"
orering of the keys and which contains all of the elements in the
supplied Collection. This runs in n*log(n) time.
collection
- the new Set will be initialized with all
of the elements in this Collection
TreeSet
public TreeSet(Comparator comparator)
Construct a new TreeSet whose backing TreeMap uses the supplied
Comparator. Elements that are not mutually comparable will cause
ClassCastExceptions down the road.
comparator
- the Comparator this Set will use
TreeSet
public TreeSet(SortedSet sortedSet)
Construct a new TreeSet, using the same key ordering as the supplied
SortedSet and containing all of the elements in the supplied SortedSet.
This constructor runs in linear time.
sortedSet
- the new TreeSet will use this SortedSet's comparator
and will initialize itself with all its elements
add
public boolean add(Object obj)
Adds the spplied Object to the Set if it is not already in the Set;
returns true if the element is added, false otherwise.
- add in interface Set
- add in interface Collection
- add in interface AbstractCollection
obj
- the Object to be added to this Set
clone
public Object clone()
Returns a shallow copy of this Set. The elements are not cloned.
- clone in interface Object
headSet
public SortedSet headSet(Object to)
Returns a view of this Set including all elements less than
to
. The returned set is backed by the original, so changes
in one appear in the other. The subset will throw an
IllegalArgumentException
for any attempt to access or add an
element beyond the specified cutoff. The returned set does not include
the endpoint; if you want inclusion, pass the successor element.
- headSet in interface SortedSet
to
- the (exclusive) cutoff point
- a view of the set less than the cutoff
ClassCastException
- if to
is not compatible with
the comparator (or is not Comparable, for natural ordering)NullPointerException
- if to is null, but the comparator does not
tolerate null elements
remove
public boolean remove(Object obj)
If the supplied Object is in this Set, it is removed, and true is
returned; otherwise, false is returned.
- remove in interface Set
- remove in interface Collection
- remove in interface AbstractCollection
obj
- the Object to remove from this Set
- true if the set was modified
subSet
public SortedSet subSet(Object from,
Object to)
Returns a view of this Set including all elements greater or equal to
from
and less than
to
(a half-open interval).
The returned set is backed by the original, so changes in one appear in
the other. The subset will throw an
IllegalArgumentException
for any attempt to access or add an element beyond the specified cutoffs.
The returned set includes the low endpoint but not the high; if you want
to reverse this behavior on either end, pass in the successor element.
- subSet in interface SortedSet
from
- the (inclusive) low cutoff pointto
- the (exclusive) high cutoff point
- a view of the set between the cutoffs
tailSet
public SortedSet tailSet(Object from)
Returns a view of this Set including all elements greater or equal to
from
. The returned set is backed by the original, so
changes in one appear in the other. The subset will throw an
IllegalArgumentException
for any attempt to access or add an
element beyond the specified cutoff. The returned set includes the
endpoint; if you want to exclude it, pass in the successor element.
- tailSet in interface SortedSet
from
- the (inclusive) low cutoff point
- a view of the set above the cutoff
ClassCastException
- if from
is not compatible with
the comparator (or is not Comparable, for natural ordering)NullPointerException
- if from is null, but the comparator
does not tolerate null elements
TreeSet.java -- a class providing a TreeMap-backed SortedSet
Copyright (C) 1999, 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
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