Class LeftistHeap<K,V>
- java.lang.Object
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- org.jheaps.tree.SkewHeap<K,V>
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- org.jheaps.tree.LeftistHeap<K,V>
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- Type Parameters:
K
- the type of keys maintained by this heapV
- the type of values maintained by this heap
- All Implemented Interfaces:
java.io.Serializable
,AddressableHeap<K,V>
,MergeableAddressableHeap<K,V>
public class LeftistHeap<K,V> extends SkewHeap<K,V>
Leftist heaps. The heap is sorted according to the natural ordering of its keys, or by aComparator
provided at heap creation time, depending on which constructor is used.Operations
insert
,deleteMin
,decreaseKey
, anddelete
take worst-case O(log(n)). OperationfindMin
is worst-case O(1).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 theHeap
interface. (SeeComparable
orComparator
for a precise definition of consistent with equals.) This is so because theHeap
interface is defined in terms of theequals
operation, but this heap performs all key comparisons using itscompareTo
(orcompare
) 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 withequals
; it just fails to obey the general contract of theHeap
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.
- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description (package private) static class
LeftistHeap.LeftistNode<K,V>
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Nested classes/interfaces inherited from class org.jheaps.tree.SkewHeap
SkewHeap.Node<K,V>
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Nested classes/interfaces inherited from interface org.jheaps.AddressableHeap
AddressableHeap.Handle<K,V>
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Field Summary
Fields Modifier and Type Field Description private static long
serialVersionUID
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Fields inherited from class org.jheaps.tree.SkewHeap
comparator, other, root, size
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Constructor Summary
Constructors Constructor Description LeftistHeap()
Constructs a new, empty heap, using the natural ordering of its keys.LeftistHeap(java.util.Comparator<? super K> comparator)
Constructs a new, empty heap, ordered according to the given comparator.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected SkewHeap.Node<K,V>
createNode(K key, V value)
Factory method for new node creationprotected void
swapChildren(SkewHeap.Node<K,V> n)
Swap the children of a node.protected SkewHeap.Node<K,V>
union(SkewHeap.Node<K,V> root1, SkewHeap.Node<K,V> root2)
Top-down union two skew heapsprotected SkewHeap.Node<K,V>
unionWithComparator(SkewHeap.Node<K,V> root1, SkewHeap.Node<K,V> root2)
Top-down union of two leftist heaps with comparator.-
Methods inherited from class org.jheaps.tree.SkewHeap
clear, comparator, delete, deleteMin, findMin, getParent, insert, insert, isEmpty, meld, size, unlinkAndUnionChildren, unlinkRightChild
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Field Detail
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serialVersionUID
private static final long serialVersionUID
- See Also:
- Constant Field Values
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Constructor Detail
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LeftistHeap
public LeftistHeap()
Constructs a new, empty heap, using the natural ordering of its keys.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 aClassCastException
for any keysk1
andk2
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), theinsert(Object key)
call will throw aClassCastException
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LeftistHeap
public LeftistHeap(java.util.Comparator<? super K> comparator)
Constructs a new, empty heap, ordered according to the given comparator.All keys inserted into the heap must be mutually comparable by the given comparator:
comparator.compare(k1, k2)
must not throw aClassCastException
for any keysk1
andk2
in the heap. If the user attempts to put a key into the heap that violates this constraint, theinsert(Object key)
call will throw aClassCastException
.- Parameters:
comparator
- the comparator that will be used to order this heap. Ifnull
, the natural ordering of the keys will be used.
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Method Detail
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createNode
protected SkewHeap.Node<K,V> createNode(K key, V value)
Factory method for new node creation- Overrides:
createNode
in classSkewHeap<K,V>
- Parameters:
key
- the keyvalue
- the value- Returns:
- the newly created node
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swapChildren
protected void swapChildren(SkewHeap.Node<K,V> n)
Swap the children of a node.- Parameters:
n
- the node
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union
protected SkewHeap.Node<K,V> union(SkewHeap.Node<K,V> root1, SkewHeap.Node<K,V> root2)
Top-down union two skew heaps
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unionWithComparator
protected SkewHeap.Node<K,V> unionWithComparator(SkewHeap.Node<K,V> root1, SkewHeap.Node<K,V> root2)
Top-down union of two leftist heaps with comparator.- Overrides:
unionWithComparator
in classSkewHeap<K,V>
- Parameters:
root1
- the root of the first heaproot2
- the root of the right heap- Returns:
- the new root of the merged heap
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