org.apache.commons.math3.geometry.partitioning.utilities

## Class AVLTree.Node

- java.lang.Object
- - org.apache.commons.math3.geometry.partitioning.utilities.AVLTree.Node

Enclosing class:
  AVLTree<T extends java.lang.Comparable<T>>

    public class AVLTree.Node
    extends java.lang.Object

This class implements AVL trees nodes.

AVL tree nodes implement all the logical structure of the tree. Nodes are created by the `AVLTree` class.

The nodes are not independant from each other but must obey specific balancing constraints and the tree structure is rearranged as elements are inserted or deleted from the tree. The creation, modification and tree-related navigation methods have therefore restricted access. Only the order-related navigation, reading and delete methods are public.

See Also:
  `AVLTree`

### Field Summary

Fields
`private T` `element` Element contained in the current node.
`private AVLTree.Node` `left` Left sub-tree.
`private AVLTree.Node` `parent` Parent tree.
`private AVLTree.Node` `right` Right sub-tree.
`private AVLTree.Skew` `skew` Skew factor.

### Constructor Summary

Constructors
Constructor and Description
`AVLTree.Node(T element, AVLTree.Node parent)` Build a node for a specified element.

### Method Summary

Methods
`void` `delete()` Delete the node from the tree.
`T` `getElement()` Get the contained element.
`(package private) AVLTree.Node` `getLargest()` Get the node whose element is the largest one in the tree rooted at this node.
`AVLTree.Node` `getNext()` Get the node containing the next larger or equal element.
`AVLTree.Node` `getPrevious()` Get the node containing the next smaller or equal element.
`(package private) AVLTree.Node` `getSmallest()` Get the node whose element is the smallest one in the tree rooted at this node.
`(package private) boolean` `insert(T newElement)` Insert an element in a sub-tree.
`private boolean` `rebalanceLeftGrown()` Re-balance the instance as left sub-tree has grown.
`private boolean` `rebalanceLeftShrunk()` Re-balance the instance as left sub-tree has shrunk.
`private boolean` `rebalanceRightGrown()` Re-balance the instance as right sub-tree has grown.
`private boolean` `rebalanceRightShrunk()` Re-balance the instance as right sub-tree has shrunk.
`private void` `rotateCCW()` Perform a counter-clockwise rotation rooted at the instance.
`private void` `rotateCW()` Perform a clockwise rotation rooted at the instance.
`(package private) int` `size()` Get the number of elements of the tree rooted at this node.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Field Detail

#### element

    private T extends java.lang.Comparable<T> element

Element contained in the current node.

#### left

    private AVLTree.Node left

Left sub-tree.

#### right

    private AVLTree.Node right

Right sub-tree.

#### parent

    private AVLTree.Node parent

Parent tree.

#### skew

    private AVLTree.Skew skew

Skew factor.

### Constructor Detail

#### AVLTree.Node

    AVLTree.Node(T element,
                AVLTree.Node parent)

Build a node for a specified element.

Parameters:
  `element` - element
  `parent` - parent node

### Method Detail

#### getElement

    public T getElement()

Get the contained element.

Returns:
  element contained in the node

#### size

    int size()

Get the number of elements of the tree rooted at this node.

Returns:
  number of elements contained in the tree rooted at this node

#### getSmallest

    AVLTree.Node getSmallest()

Get the node whose element is the smallest one in the tree rooted at this node.

Returns:
  the tree node containing the smallest element in the tree rooted at this node or null if the tree is empty
See Also:
  `getLargest()`

#### getLargest

    AVLTree.Node getLargest()

Get the node whose element is the largest one in the tree rooted at this node.

Returns:
  the tree node containing the largest element in the tree rooted at this node or null if the tree is empty
See Also:
  `getSmallest()`

#### getPrevious

    public AVLTree.Node getPrevious()

Get the node containing the next smaller or equal element.

Returns:
  node containing the next smaller or equal element or null if there is no smaller or equal element in the tree
See Also:
  `getNext()`

#### getNext

    public AVLTree.Node getNext()

Get the node containing the next larger or equal element.

Returns:
  node containing the next larger or equal element (in which case the node is guaranteed not to be empty) or null if there is no larger or equal element in the tree
See Also:
  `getPrevious()`

#### insert

    boolean insert(T newElement)

Insert an element in a sub-tree.

Parameters:
  `newElement` - element to insert
Returns:
  true if the parent tree should be re-Skew.BALANCED

#### delete

    public void delete()

Delete the node from the tree.

#### rebalanceLeftGrown

    private boolean rebalanceLeftGrown()

Re-balance the instance as left sub-tree has grown.

Returns:
  true if the parent tree should be reSkew.BALANCED too

#### rebalanceRightGrown

    private boolean rebalanceRightGrown()

Re-balance the instance as right sub-tree has grown.

Returns:
  true if the parent tree should be reSkew.BALANCED too

#### rebalanceLeftShrunk

    private boolean rebalanceLeftShrunk()

Re-balance the instance as left sub-tree has shrunk.

Returns:
  true if the parent tree should be reSkew.BALANCED too

#### rebalanceRightShrunk

    private boolean rebalanceRightShrunk()

Re-balance the instance as right sub-tree has shrunk.

Returns:
  true if the parent tree should be reSkew.BALANCED too

#### rotateCW

    private void rotateCW()

Perform a clockwise rotation rooted at the instance.

The skew factor are not updated by this method, they must be updated by the caller

#### rotateCCW

    private void rotateCCW()

Perform a counter-clockwise rotation rooted at the instance.

The skew factor are not updated by this method, they must be updated by the caller