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java.lang.Object | +--harpoon.Util.Collections.AbstractHeap | +--harpoon.Util.Collections.BinaryHeap
BinaryHeap
is an implementation of a binary heap.
The implementation in CLR is followed, except the comparisons
are reversed to keep the minimum element on the top of
the heap. In addition, the function names downheap()
(for what CLR calls 'heapify') and upheap()
(which
is part of the INSERT operation) have been adopted from
Sedgewick's book.
Heap
Constructor Summary | |
BinaryHeap()
Creates a new, empty BinaryHeap , which will
use the keys' natural order. |
|
BinaryHeap(Collection collection,
Comparator comparator)
Builds a binary heap from a collection of Map.Entry s
and a key comparator. |
|
BinaryHeap(Comparator c)
Creates a new, empty BinaryHeap with the
specified comparator. |
|
BinaryHeap(Heap h)
Builds a binary heap from the given heap, using the same key comparator as the given heap. |
Method Summary | |
void |
clear()
Removes all entries from this Heap . |
void |
decreaseKey(Map.Entry me,
Object newkey)
Replace the key in the specified map entry with the specified smaller key. |
void |
delete(Map.Entry me)
Remove the specified map entry from the mapping. |
Collection |
entries()
Returns a collection view of all the Map.Entry s
in this Heap . |
Map.Entry |
extractMinimum()
Remove and return a map entry with minimal key. |
Map.Entry |
insert(Object key,
Object value)
Inserts a node with the specified key and value into the Heap . |
static void |
main(String[] args)
Self-test function. |
Map.Entry |
minimum()
Returns a mapping entry with minimal key. |
protected Object |
setKey(Map.Entry me,
Object newkey)
This method should set the key for the specified Map.Entry to the given newkey . |
int |
size()
Returns the number of entries in this Heap . |
void |
union(Heap h)
Merges all of the mappings from the specified Heap
into this Heap . |
void |
updateKey(Map.Entry me,
Object newkey)
Replace the key in the specified map entry with the specified key, which may be either larger or smaller than its current key. |
Methods inherited from class harpoon.Util.Collections.AbstractHeap |
comparator, entryComparator, equals, hashCode, insert, isEmpty, keyComparator, toString |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
public BinaryHeap()
BinaryHeap
, which will
use the keys' natural order.
public BinaryHeap(Comparator c)
BinaryHeap
with the
specified comparator.
public BinaryHeap(Heap h)
public BinaryHeap(Collection collection, Comparator comparator)
Map.Entry
s
and a key comparator.
O(n) time.
Method Detail |
public Map.Entry insert(Object key, Object value)
Heap
Heap
. Returns the generated Map.Entry
which may be stored and eventually passed back to
decreaseKey()
or delete
to remove
this node.
insert
in interface Heap
insert
in class AbstractHeap
public Map.Entry minimum()
Heap
minimum
in interface Heap
minimum
in class AbstractHeap
public Map.Entry extractMinimum()
Heap
extractMinimum
in interface Heap
extractMinimum
in class AbstractHeap
public void union(Heap h)
Heap
Heap
into this Heap
. Note that duplicates are
permitted. After calling union()
, the Heap
passed in as an argument will be empty.
Note that usually efficient implementations of this method require
that the Heap
argument be from the same implementation
as this
. (That is, they must both be binomial heaps, or
both fibonacci heaps, etc.)
union
in interface Heap
union
in class AbstractHeap
public void decreaseKey(Map.Entry me, Object newkey)
Heap
decreaseKey
in interface Heap
decreaseKey
in class AbstractHeap
public void updateKey(Map.Entry me, Object newkey)
Heap
updateKey
in interface Heap
updateKey
in class AbstractHeap
public void delete(Map.Entry me)
Heap
delete
in interface Heap
delete
in class AbstractHeap
public void clear()
Heap
Heap
.
clear
in interface Heap
clear
in class AbstractHeap
public int size()
Heap
Heap
.
size
in interface Heap
size
in class AbstractHeap
public Collection entries()
Heap
Map.Entry
s
in this Heap
.
entries
in interface Heap
entries
in class AbstractHeap
protected final Object setKey(Map.Entry me, Object newkey)
AbstractHeap
Map.Entry
to the given newkey
.
Implementation is optional, but it is required if you use the
default implementation of updateKey()
.
setKey
in class AbstractHeap
public static void main(String[] args)
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