K - the type of keys maintained by this heappublic class MinMaxBinaryArrayDoubleEndedHeap<K> extends Object implements DoubleEndedHeap<K>, Serializable
Comparator provided at heap creation time, depending on which
constructor is used.
For details about the implementation see the following paper:
The implementation uses an array in order to store the elements and
automatically maintains the size of the array much like a
Vector does, providing amortized O(log(n)) time cost for
the insert, deleteMin, and deleteMax operations.
Operations findMin and findMax are worst-case O(1). The
bounds are worst-case if the user initializes the heap with a capacity larger
or equal to the total number of elements that are going to be inserted into
the heap.
Constructing such a heap from an array of elements can be performed using the
method heapify(Object[]) or heapify(Object[], Comparator)
in linear time.
Note that the ordering maintained by this heap, like any heap, and whether or
not an explicit comparator is provided, must be consistent with
equals if this heap is to correctly implement the Heap
interface. (See Comparable or Comparator for a precise
definition of consistent with equals.) This is so because the
Heap interface is defined in terms of the equals operation,
but this heap performs all key comparisons using its compareTo (or
compare) method, so two keys that are deemed equal by this method
are, from the standpoint of this heap, equal. The behavior of a heap
is well-defined even if its ordering is inconsistent with
equals; it just fails to obey the general contract of the
Heap interface.
Note that this implementation is not synchronized. If multiple threads access a heap concurrently, and at least one of the threads modifies the heap structurally, it must be synchronized externally. (A structural modification is any operation that adds or deletes one or more elements or changing the key of some element.) This is typically accomplished by synchronizing on some object that naturally encapsulates the heap.
| Modifier and Type | Field and Description |
|---|---|
static int |
DEFAULT_HEAP_CAPACITY
Default initial capacity of the heap.
|
| Constructor and Description |
|---|
MinMaxBinaryArrayDoubleEndedHeap()
Constructs a new, empty heap, using the natural ordering of its keys.
|
MinMaxBinaryArrayDoubleEndedHeap(Comparator<? super K> comparator)
Constructs a new, empty heap, ordered according to the given comparator.
|
MinMaxBinaryArrayDoubleEndedHeap(Comparator<? super K> comparator,
int capacity)
Constructs a new, empty heap, with a provided initial capacity ordered
according to the given comparator.
|
MinMaxBinaryArrayDoubleEndedHeap(int capacity)
Constructs a new, empty heap, with a provided initial capacity using the
natural ordering of its keys.
|
| Modifier and Type | Method and Description |
|---|---|
void |
clear()
Clear all the elements of this heap.
|
Comparator<? super K> |
comparator()
Returns the comparator used to order the keys in this heap, or
null if this heap uses the natural
ordering of its keys. |
K |
deleteMax()
Delete and return an element with the maximum key.
|
K |
deleteMin()
Delete and return an element with the minimum key.
|
K |
findMax()
Find an element with the maximum key.
|
K |
findMin()
Find an element with the minimum key.
|
static <K> MinMaxBinaryArrayDoubleEndedHeap<K> |
heapify(K[] array)
Create a heap from an array of elements.
|
static <K> MinMaxBinaryArrayDoubleEndedHeap<K> |
heapify(K[] array,
Comparator<? super K> comparator)
Create a heap from an array of elements.
|
void |
insert(K key)
Insert a key into the heap.
|
boolean |
isEmpty()
Returns
true if this heap is empty. |
long |
size()
Returns the number of elements in this heap.
|
public static final int DEFAULT_HEAP_CAPACITY
public MinMaxBinaryArrayDoubleEndedHeap()
All keys inserted into the heap must implement the Comparable
interface. Furthermore, all such keys must be mutually
comparable: k1.compareTo(k2) must not throw a
ClassCastException for any keys k1 and k2 in the
heap. If the user attempts to put a key into the heap that violates this
constraint (for example, the user attempts to put a string key into a
heap whose keys are integers), the insert(Object key) call will
throw a ClassCastException.
The initial capacity of the heap is DEFAULT_HEAP_CAPACITY and
adjusts automatically based on the sequence of insertions and deletions.
public MinMaxBinaryArrayDoubleEndedHeap(int capacity)
All keys inserted into the heap must implement the Comparable
interface. Furthermore, all such keys must be mutually
comparable: k1.compareTo(k2) must not throw a
ClassCastException for any keys k1 and k2 in the
heap. If the user attempts to put a key into the heap that violates this
constraint (for example, the user attempts to put a string key into a
heap whose keys are integers), the insert(Object key) call will
throw a ClassCastException.
The initial capacity of the heap is provided by the user and is adjusted automatically based on the sequence of insertions and deletions. The capacity will never become smaller than the initial requested capacity.
capacity - the initial heap capacitypublic MinMaxBinaryArrayDoubleEndedHeap(Comparator<? super K> comparator)
All keys inserted into the heap must be mutually comparable by
the given comparator: comparator.compare(k1,
k2) must not throw a ClassCastException for any keys k1
and k2 in the heap. If the user attempts to put a key into the
heap that violates this constraint, the insert(Object key) call
will throw a ClassCastException.
The initial capacity of the heap is DEFAULT_HEAP_CAPACITY and
adjusts automatically based on the sequence of insertions and deletions.
comparator - the comparator that will be used to order this heap. If
null, the natural ordering of
the keys will be used.public MinMaxBinaryArrayDoubleEndedHeap(Comparator<? super K> comparator, int capacity)
All keys inserted into the heap must be mutually comparable by
the given comparator: comparator.compare(k1,
k2) must not throw a ClassCastException for any keys k1
and k2 in the heap. If the user attempts to put a key into the
heap that violates this constraint, the insert(Object key) call
will throw a ClassCastException.
The initial capacity of the heap is provided by the user and is adjusted automatically based on the sequence of insertions and deletions.The capacity will never become smaller than the initial requested capacity.
comparator - the comparator that will be used to order this heap. If
null, the natural ordering of
the keys will be used.capacity - the initial heap capacitypublic static <K> MinMaxBinaryArrayDoubleEndedHeap<K> heapify(K[] array)
K - the type of keys maintained by the heaparray - an array of elementsIllegalArgumentException - in case the array is nullpublic static <K> MinMaxBinaryArrayDoubleEndedHeap<K> heapify(K[] array, Comparator<? super K> comparator)
K - the type of keys maintained by the heaparray - an array of elementscomparator - the comparator to useIllegalArgumentException - in case the array is nullpublic K findMax()
findMax in interface DoubleEndedHeap<K>public K deleteMax()
deleteMax in interface DoubleEndedHeap<K>public K findMin()
public void insert(K key)
key - the key to insertpublic K deleteMin()
public boolean isEmpty()
true if this heap is empty.public long size()
public Comparator<? super K> comparator()
null if this heap uses the natural
ordering of its keys.comparator in interface Heap<K>null if this heap uses the natural ordering of its keysCopyright © 2018. All rights reserved.