BinaryTreeSoftHeap (JHeaps)

java.lang.Object
- org.jheaps.tree.BinaryTreeSoftHeap<K>

Type Parameters:

K - the type of keys maintained by this heap

All Implemented Interfaces:

Serializable, Heap<K>, MergeableHeap<K>
```
public class BinaryTreeSoftHeap<K>
extends Object
implements Heap<K>, MergeableHeap<K>, Serializable
```
A binary tree soft heap. The heap is sorted according to the natural ordering of its keys, or by a Comparator provided at heap creation time, depending on which constructor is used.
If n elements are inserted into a soft heap, then up to εn of the elements still contained in the heap, for a given error parameter ε, may be corrupted, i.e., have their keys artificially increased. In exchange for allowing these corruptions, each soft heap operation is performed in O(log 1/ε) amortized time. Note that n here is the number of elements inserted into the heaps, not the current number of elements in the heap which may be considerably smaller. Moreover the user has no control on which elements may be corrupted.
This variant of the soft heap is due to Kaplan and Zwick, described in detail in the following paper:
- Haim Kaplan and Uri Zwick, A simpler implementation and analysis of Chazelle's Soft Heaps, In Proceedings of the 20th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2009), 477--485, 2009.
Note that the ordering maintained by a soft 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 a pairing 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 the 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.
Author:

Dimitrios Michail

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor and Description
`BinaryTreeSoftHeap(double errorRate)` Constructs a new, empty heap, using the natural ordering of its keys.
`BinaryTreeSoftHeap(double errorRate, Comparator<? super K> comparator)` Constructs a new, empty heap, ordered according to the given comparator.

Method Summary

All Methods Instance Methods Concrete Methods
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`	`deleteMin()` Delete and return an element with the minimum key.
`K`	`findMin()` Find an element with the minimum key.
`void`	`insert(K key)` Insert a key into the heap.
`boolean`	`isEmpty()` Returns `true` if this heap is empty.
`void`	`meld(MergeableHeap<K> other)` Meld a heap into the current heap.
`long`	`size()` Returns the number of elements in this heap.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - BinaryTreeSoftHeap
```
public BinaryTreeSoftHeap(double errorRate)
```
    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 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.
    
    Parameters:
    
    errorRate - the error rate
    
    Throws:
    
    IllegalArgumentException - if the error rate is less or equal to zero
    
    IllegalArgumentException - if the error rate is greater or equal to one
  - BinaryTreeSoftHeap
```
public BinaryTreeSoftHeap(double errorRate,
                          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 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.
    
    Parameters:
    
    errorRate - the error rate
    
    comparator - the comparator that will be used to order this heap. If null, the natural ordering of the keys will be used.
    
    Throws:
    
    IllegalArgumentException - if the error rate is less or equal to zero
    
    IllegalArgumentException - if the error rate is greater or equal to one
- Method Detail
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if this heap is empty.
    
    Specified by:
    
    isEmpty in interface Heap<K>
    
    Returns:
    
    true if this heap is empty, false otherwise
  - size
```
public long size()
```
    Returns the number of elements in this heap.
    
    Specified by:
    
    size in interface Heap<K>
    
    Returns:
    
    the number of elements in this heap
  - comparator
```
public 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.
    
    Specified by:
    
    comparator in interface Heap<K>
    
    Returns:
    
    the comparator used to order the keys in this heap, or null if this heap uses the natural ordering of its keys
  - clear
```
public void clear()
```
    Clear all the elements of this heap.
    
    Specified by:
    
    clear in interface Heap<K>
  - meld
```
public void meld(MergeableHeap<K> other)
```
    Meld a heap into the current heap. After the operation the other heap will be empty and will not permit further insertions.
    
    Specified by:
    
    meld in interface MergeableHeap<K>
    
    Parameters:
    
    other - a merge-able heap
    
    Throws:
    
    IllegalArgumentException - if other has a different error rate
  - insert
```
public void insert(K key)
```
    Insert a key into the heap.
    
    Specified by:
    
    insert in interface Heap<K>
    
    Parameters:
    
    key - the key to insert
  - findMin
```
public K findMin()
```
    Find an element with the minimum key.
    
    Specified by:
    
    findMin in interface Heap<K>
    
    Returns:
    
    an element with the minimum key
  - deleteMin
```
public K deleteMin()
```
    Delete and return an element with the minimum key. If multiple such elements exists, only one of them will be deleted.
    
    Specified by:
    
    deleteMin in interface Heap<K>
    
    Returns:
    
    the deleted element with the minimum key

Class BinaryTreeSoftHeap<K>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

BinaryTreeSoftHeap

BinaryTreeSoftHeap

Method Detail

isEmpty

size

comparator

clear

meld

insert

findMin

deleteMin