Class DaryArrayAddressableHeap<K,V>
- java.lang.Object
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- org.jheaps.array.AbstractArrayAddressableHeap<K,V>
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- org.jheaps.array.DaryArrayAddressableHeap<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>
public class DaryArrayAddressableHeap<K,V> extends AbstractArrayAddressableHeap<K,V> implements java.io.Serializable
An array based d-ary addressable heap. 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.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_d(n)) time cost for theinsert
and amortized O(d log_d(n)) for thedeleteMin
operation. OperationfindMin
, is a worst-case O(1) operation. Operationsdelete
anddecreaseKey
take worst-case O(log(n)) time. 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(int, Object[], Object[])
orheapify(int, Object[], Object[], Comparator)
in linear time.Note that the ordering maintained by a d-ary 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 a binary heap performs all key comparisons using itscompareTo
(orcompare
) method, so two keys that are deemed equal by this method are, from the standpoint of the d-ary 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
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Nested classes/interfaces inherited from class org.jheaps.array.AbstractArrayAddressableHeap
AbstractArrayAddressableHeap.ArrayHandle
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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 protected int
d
Degreeprivate static java.lang.String
D_ARY_HEAPS_MUST_HAVE_AT_LEAST_2_CHILDREN_PER_NODE
static int
DEFAULT_HEAP_CAPACITY
Default initial capacity of the binary heap.private static long
serialVersionUID
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Fields inherited from class org.jheaps.array.AbstractArrayAddressableHeap
array, comparator, DOWNSIZING_MIN_HEAP_CAPACITY, MAX_HEAP_CAPACITY, MIN_HEAP_CAPACITY, minCapacity, NO_INDEX, size
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Constructor Summary
Constructors Constructor Description DaryArrayAddressableHeap(int d)
Constructs a new, empty heap, using the natural ordering of its keys.DaryArrayAddressableHeap(int d, int capacity)
Constructs a new, empty heap, with a provided initial capacity using the natural ordering of its keys.DaryArrayAddressableHeap(int d, java.util.Comparator<? super K> comparator)
Constructs a new, empty heap, ordered according to the given comparator.DaryArrayAddressableHeap(int d, java.util.Comparator<? super K> comparator, int capacity)
Constructs a new, empty heap, with a provided initial capacity ordered according to the given comparator.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description protected void
ensureCapacity(int capacity)
Ensure that the array representation has the necessary capacity.protected void
fixdown(int k)
protected void
fixdownWithComparator(int k)
protected void
fixup(int k)
protected void
fixupWithComparator(int k)
protected void
forceFixup(int k)
java.util.Iterator<AddressableHeap.Handle<K,V>>
handlesIterator()
Get an iterator for all handles currently in the heap.static <K,V>
DaryArrayAddressableHeap<K,V>heapify(int d, K[] keys, V[] values)
Create a heap from an array of elements.static <K,V>
DaryArrayAddressableHeap<K,V>heapify(int d, K[] keys, V[] values, java.util.Comparator<? super K> comparator)
Create a heap from an array of elements.-
Methods inherited from class org.jheaps.array.AbstractArrayAddressableHeap
checkCapacity, clear, comparator, deleteMin, findMin, insert, insert, isEmpty, size
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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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D_ARY_HEAPS_MUST_HAVE_AT_LEAST_2_CHILDREN_PER_NODE
private static final java.lang.String D_ARY_HEAPS_MUST_HAVE_AT_LEAST_2_CHILDREN_PER_NODE
- See Also:
- Constant Field Values
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DEFAULT_HEAP_CAPACITY
public static final int DEFAULT_HEAP_CAPACITY
Default initial capacity of the binary heap.- See Also:
- Constant Field Values
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d
protected int d
Degree
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Constructor Detail
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DaryArrayAddressableHeap
public DaryArrayAddressableHeap(int d)
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
.The initial capacity of the heap is
DEFAULT_HEAP_CAPACITY
and adjusts automatically based on the sequence of insertions and deletions.- Parameters:
d
- the number of children of each node in the d-ary heap- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2
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DaryArrayAddressableHeap
public DaryArrayAddressableHeap(int d, int capacity)
Constructs a new, empty heap, with a provided initial capacity 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
.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.
- Parameters:
d
- the number of children of each node in the d-ary heapcapacity
- the initial heap capacity- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2
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DaryArrayAddressableHeap
public DaryArrayAddressableHeap(int d, 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
.The initial capacity of the heap is
DEFAULT_HEAP_CAPACITY
and adjusts automatically based on the sequence of insertions and deletions.- Parameters:
d
- the number of children of each node in the d-ary heapcomparator
- the comparator that will be used to order this heap. Ifnull
, the natural ordering of the keys will be used.- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2 *
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DaryArrayAddressableHeap
public DaryArrayAddressableHeap(int d, java.util.Comparator<? super K> comparator, int capacity)
Constructs a new, empty heap, with a provided initial capacity 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
.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.
- Parameters:
d
- the number of children of each node in the d-ary heapcomparator
- the comparator that will be used to order this heap. Ifnull
, the natural ordering of the keys will be used.capacity
- the initial heap capacity- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2
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Method Detail
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heapify
public static <K,V> DaryArrayAddressableHeap<K,V> heapify(int d, K[] keys, V[] values)
Create a heap from an array of elements. The elements of the array are not destroyed. The method has linear time complexity.- Type Parameters:
K
- the type of keys maintained by the heapV
- the type of values maintained by the heap- Parameters:
d
- the number of children of the d-ary heapkeys
- an array of keysvalues
- an array of values, can be null- Returns:
- a d-ary heap
- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2java.lang.IllegalArgumentException
- in case the keys array is nulljava.lang.IllegalArgumentException
- in case the values array has different length than the keys array
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heapify
public static <K,V> DaryArrayAddressableHeap<K,V> heapify(int d, K[] keys, V[] values, java.util.Comparator<? super K> comparator)
Create a heap from an array of elements. The elements of the array are not destroyed. The method has linear time complexity.- Type Parameters:
K
- the type of keys maintained by the heapV
- the type of values maintained by the heap- Parameters:
d
- the number of children of the d-ary heapkeys
- an array of keysvalues
- an array of values, can be nullcomparator
- the comparator to use- Returns:
- a d-ary heap
- Throws:
java.lang.IllegalArgumentException
- in case the number of children per node are less than 2java.lang.IllegalArgumentException
- in case the keys array is nulljava.lang.IllegalArgumentException
- in case the values array has different length than the keys array
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handlesIterator
public java.util.Iterator<AddressableHeap.Handle<K,V>> handlesIterator()
Get an iterator for all handles currently in the heap. This method is especially useful when building a heap using the heapify method. Unspecified behavior will occur if the heap is modified while using this iterator.- Returns:
- an iterator which will return all handles of the heap
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ensureCapacity
protected void ensureCapacity(int capacity)
Ensure that the array representation has the necessary capacity.- Specified by:
ensureCapacity
in classAbstractArrayAddressableHeap<K,V>
- Parameters:
capacity
- the requested capacity
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forceFixup
protected void forceFixup(int k)
- Specified by:
forceFixup
in classAbstractArrayAddressableHeap<K,V>
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fixup
protected void fixup(int k)
- Specified by:
fixup
in classAbstractArrayAddressableHeap<K,V>
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fixupWithComparator
protected void fixupWithComparator(int k)
- Specified by:
fixupWithComparator
in classAbstractArrayAddressableHeap<K,V>
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fixdown
protected void fixdown(int k)
- Specified by:
fixdown
in classAbstractArrayAddressableHeap<K,V>
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fixdownWithComparator
protected void fixdownWithComparator(int k)
- Specified by:
fixdownWithComparator
in classAbstractArrayAddressableHeap<K,V>
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