Object
- BinarySearchTree<E>

Type Parameters:

E - Comparable

All Implemented Interfaces:

Iterable<E>
```
public class BinarySearchTree<E extends Comparable<E>>
extends Object
implements Iterable<E>
```
Represents an (optionally balanced) Binary Search Tree.
Null elements are not allowed and duplicates can have unexpected behavior. Changing the value of the elements after being inserted into the tree is undefined. It's also undefined behavior if the elements are not consistent with equals.
Use the isSelfBalancing() and setSelfBalancing(boolean) methods to enable or disable self balancing. A balanced tree minimizes the tree depth and improves search performance. When self balancing is enabled, each insert or removal rebalances the tree as necessary.
This class can be used in conjunction with the BinarySearchTreeSearchCriteria interface to perform arbitrary searches on the tree.

Since:

2.2.0

Version:

4.0.0

Author:

William Bittle

Constructor Summary

Constructors
Constructor	Description
`BinarySearchTree()`	Creates a new binary search tree with automatic balancing off.
`BinarySearchTree(boolean selfBalancing)`	Creates a new binary search tree.
`BinarySearchTree(BinarySearchTree<E> tree)`	Copy constructor.
`BinarySearchTree(BinarySearchTree<E> tree, boolean selfBalancing)`	Copy constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`balanceTree()`	Re-balances the entire tree.
`void`	`clear()`	Empties this tree.
`boolean`	`contains(E comparable)`	Attempts to find the given comparable object within the tree.
`int`	`getHeight()`	Returns the maximum depth of the tree.
`E`	`getMaximum()`	Returns the maximum value of the tree.
`E`	`getMinimum()`	Returns the minimum value of the tree.
`E`	`getRoot()`	Returns the root of the tree.
`Iterator<E>`	`headIterator(E to)`	Returns the in-order (ascending) iterator.
`Iterator<E>`	`inOrderIterator()`	Returns a new iterator for traversing the tree in order.
`boolean`	`insert(E comparable)`	Inserts the given comparable into this binary tree.
`protected boolean`	`insertSubtree(BinarySearchTree<E> tree)`	Inserts the given subtree into this binary tree.
`boolean`	`isEmpty()`	Returns true if this tree is empty.
`boolean`	`isSelfBalancing()`	Returns true if this tree is self balancing.
`Iterator<E>`	`iterator()`	Returns the in-order (ascending) iterator.
`boolean`	`remove(E comparable)`	Removes the comparable object from the tree returning true if the comparable was found and removed
`E`	`removeMaximum()`	Removes the maximum value node from this tree.
`E`	`removeMinimum()`	Removes the minimum value node from this tree.
`protected boolean`	`removeSubtree(E comparable)`	Removes the node containing the given value and the corresponding subtree from this tree.
`Iterator<E>`	`reverseOrderIterator()`	Returns a new iterator for traversing the tree in reverse order.
`<T extends BinarySearchTreeSearchCriteria<E>> T`	`search(T criteria)`	Performs a binary search on this tree given the criteria.
`void`	`setSelfBalancing(boolean flag)`	Sets whether this tree should self balance.
`int`	`size()`	Returns the number of elements in the tree.
`Iterator<E>`	`subsetIterator(E from, E to)`	Returns the in-order (ascending) iterator.
`Iterator<E>`	`tailIterator(E from)`	Returns the in-order (ascending) iterator starting from the given node.
`String`	`toString()`

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface Iterable
forEach, spliterator

- Constructor Detail
  - BinarySearchTree
```
public BinarySearchTree()
```
    Creates a new binary search tree with automatic balancing off.
  - BinarySearchTree
```
public BinarySearchTree(boolean selfBalancing)
```
    Creates a new binary search tree.
    
    Parameters:
    
    selfBalancing - true if the tree should automatically balance
  - BinarySearchTree
```
public BinarySearchTree(BinarySearchTree<E> tree)
```
    Copy constructor.
    This performs a deep copy of the elements in the tree. The values contained in the tree are shallow copied.
    
    Parameters:
    
    tree - the tree to copy
    
    Since:
    
    3.0.0
  - BinarySearchTree
```
public BinarySearchTree(BinarySearchTree<E> tree,
                        boolean selfBalancing)
```
    Copy constructor.
    This performs a deep copy of the elements in the tree. The values contained in the tree are shallow copied.
    
    Parameters:
    
    tree - the tree to copy
    
    selfBalancing - true if the tree should self balance
    
    Since:
    
    3.0.0
- Method Detail
  - isSelfBalancing
```
public boolean isSelfBalancing()
```
    Returns true if this tree is self balancing.
    
    Returns:
    
    boolean
    
    Since:
    
    3.0.0
  - setSelfBalancing
```
public void setSelfBalancing(boolean flag)
```
    Sets whether this tree should self balance.
    When self balancing is enabled, adding and removing elements will perform a post step to make sure the tree stays balanced. Balancing minimizes the tree's depth, thereby increasing search performance.
    If enabled and the tree contains more than 2 elements, the tree will be balanced before this method returns.
    
    Parameters:
    
    flag - true if the tree should self balance
    
    Since:
    
    3.0.0
  - insert
```
public boolean insert(E comparable)
```
    Inserts the given comparable into this binary tree.
    Returns false if the given comparable is null.
    
    Parameters:
    
    comparable - the comparable object to insert
    
    Returns:
    
    boolean true if the insert was successful
  - remove
```
public boolean remove(E comparable)
```
    Removes the comparable object from the tree returning true if the comparable was found and removed
    If the given comparable is null, false is returned.
    
    Parameters:
    
    comparable - the comparable object
    
    Returns:
    
    boolean true if the element was found and removed
  - removeMinimum
```
public E removeMinimum()
```
    Removes the minimum value node from this tree.
    Returns null if the tree is empty.
    
    Returns:
    
    E the minimum value
  - removeMaximum
```
public E removeMaximum()
```
    Removes the maximum value node from this tree.
    Returns null if the tree is empty.
    
    Returns:
    
    E the maximum value
  - getMinimum
```
public E getMinimum()
```
    Returns the minimum value of the tree.
    Returns null if the tree is empty.
    
    Returns:
    
    E the minimum value
  - getMaximum
```
public E getMaximum()
```
    Returns the maximum value of the tree.
    Returns null if the tree is empty.
    
    Returns:
    
    E the maximum value
  - contains
```
public boolean contains(E comparable)
```
    Attempts to find the given comparable object within the tree.
    
    Parameters:
    
    comparable - the comparable object to find
    
    Returns:
    
    boolean true if the given comparable object was found
  - search
```
public <T extends BinarySearchTreeSearchCriteria<E>> T search(T criteria)
```
    Performs a binary search on this tree given the criteria.
    
    Type Parameters:
    
    T - the BinarySearchTreeSearchCriteria type
    
    Parameters:
    
    criteria - the criteria
    
    Returns:
    
    the criteria for chaining
    
    Since:
    
    3.2.0
  - getRoot
```
public E getRoot()
```
    Returns the root of the tree.
    
    Returns:
    
    E the root value; null if the tree is empty
  - clear
```
public void clear()
```
    Empties this tree.
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if this tree is empty.
    
    Returns:
    
    boolean true if empty
  - getHeight
```
public int getHeight()
```
    Returns the maximum depth of the tree.
    
    Returns:
    
    int the maximum depth
    
    Since:
    
    3.0.0
  - size
```
public int size()
```
    Returns the number of elements in the tree.
    
    Returns:
    
    int
  - iterator
```
public Iterator<E> iterator()
```
    Returns the in-order (ascending) iterator.
    
    Specified by:
    
    iterator in interface Iterable<E extends Comparable<E>>
    
    Returns:
    
    Iterator<E>
  - tailIterator
```
public Iterator<E> tailIterator(E from)
```
    Returns the in-order (ascending) iterator starting from the given node.
    
    Parameters:
    
    from - the starting value
    
    Returns:
    
    Iterator<E>
  - headIterator
```
public Iterator<E> headIterator(E to)
```
    Returns the in-order (ascending) iterator.
    
    Parameters:
    
    to - the ending value
    
    Returns:
    
    Iterator<E>
  - subsetIterator
```
public Iterator<E> subsetIterator(E from,
                                  E to)
```
    Returns the in-order (ascending) iterator.
    
    Parameters:
    
    from - the starting value
    
    to - the ending value
    
    Returns:
    
    Iterator<E>
  - inOrderIterator
```
public Iterator<E> inOrderIterator()
```
    Returns a new iterator for traversing the tree in order.
    
    Returns:
    
    Iterator<E>
  - reverseOrderIterator
```
public Iterator<E> reverseOrderIterator()
```
    Returns a new iterator for traversing the tree in reverse order.
    
    Returns:
    
    Iterator<E>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - insertSubtree
```
protected boolean insertSubtree(BinarySearchTree<E> tree)
```
    Inserts the given subtree into this binary tree.
    This method copies the elements from the given tree.
    
    Parameters:
    
    tree - the subtree
    
    Returns:
    
    boolean true if the insertion was successful
  - removeSubtree
```
protected boolean removeSubtree(E comparable)
```
    Removes the node containing the given value and the corresponding subtree from this tree.
    
    Parameters:
    
    comparable - the comparable to search for
    
    Returns:
    
    boolean true if the element was found and its subtree was removed
  - balanceTree
```
protected void balanceTree()
```
    Re-balances the entire tree.
    
    Since:
    
    3.0.0

Class BinarySearchTree<E extends Comparable<E>>

Constructor Summary

Method Summary

Methods inherited from class Object

Methods inherited from interface Iterable

Constructor Detail

BinarySearchTree

BinarySearchTree

BinarySearchTree

BinarySearchTree

Method Detail

isSelfBalancing

setSelfBalancing

insert

remove

removeMinimum

removeMaximum

getMinimum

getMaximum

contains

search

getRoot

clear

isEmpty

getHeight

size

iterator

tailIterator

headIterator

subsetIterator

inOrderIterator

reverseOrderIterator

toString

insertSubtree

removeSubtree

balanceTree