Class TreeList.AVLNode<E>
java.lang.Object
org.apache.commons.collections4.list.TreeList.AVLNode<E>
Implements an AVLNode which keeps the offset updated.
This node contains the real work.
TreeList is just there to implement List
.
The nodes don't know the index of the object they are holding. They
do know however their position relative to their parent node.
This allows to calculate the index of a node while traversing the tree.
The Faedelung calculation stores a flag for both the left and right child to indicate if they are a child (false) or a link as in linked list (true).
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate int
How many levels of left/right are below this one.private TreeList.AVLNode
<E> The left child node or the predecessor ifleftIsPrevious
.private boolean
Flag indicating that left reference is not a subtree but the predecessor.private int
The relative position, root holds absolute position.private TreeList.AVLNode
<E> The right child node or the successor ifrightIsNext
.private boolean
Flag indicating that right reference is not a subtree but the successor.private E
The stored element. -
Constructor Summary
ConstructorsModifierConstructorDescriptionprivate
AVLNode
(int relativePosition, E obj, TreeList.AVLNode<E> rightFollower, TreeList.AVLNode<E> leftFollower) Constructs a new node with a relative position.private
AVLNode
(Collection<? extends E> coll) Constructs a new AVL tree from a collection.private
AVLNode
(Iterator<? extends E> iterator, int start, int end, int absolutePositionOfParent, TreeList.AVLNode<E> prev, TreeList.AVLNode<E> next) Constructs a new AVL tree from a collection. -
Method Summary
Modifier and TypeMethodDescriptionprivate TreeList.AVLNode
<E> addAll
(TreeList.AVLNode<E> otherTree, int currentSize) Appends the elements of another tree list to this tree list by efficiently merging the two AVL trees.private TreeList.AVLNode
<E> balance()
Balances according to the AVL algorithm.(package private) TreeList.AVLNode
<E> get
(int index) Locate the element with the given index relative to the offset of the parent of this node.private int
getHeight
(TreeList.AVLNode<E> node) Returns the height of the node or -1 if the node is null.private TreeList.AVLNode
<E> Gets the left node, returning null if its a faedelung.private int
getOffset
(TreeList.AVLNode<E> node) Gets the relative position.private TreeList.AVLNode
<E> Gets the right node, returning null if its a faedelung.(package private) E
getValue()
Gets the value.private int
Returns the height difference right - left(package private) int
Locate the index that contains the specified object.(package private) TreeList.AVLNode
<E> Inserts a node at the position index.private TreeList.AVLNode
<E> insertOnLeft
(int indexRelativeToMe, E obj) private TreeList.AVLNode
<E> insertOnRight
(int indexRelativeToMe, E obj) private TreeList.AVLNode
<E> max()
Gets the rightmost child of this node.private TreeList.AVLNode
<E> min()
Gets the leftmost child of this node.(package private) TreeList.AVLNode
<E> next()
Gets the next node in the list after this one.(package private) TreeList.AVLNode
<E> previous()
Gets the node in the list before this one.private void
Sets the height by calculation.(package private) TreeList.AVLNode
<E> remove
(int index) Removes the node at a given position.private TreeList.AVLNode
<E> private TreeList.AVLNode
<E> private TreeList.AVLNode
<E> Removes this node from the tree.private TreeList.AVLNode
<E> private TreeList.AVLNode
<E> private void
setLeft
(TreeList.AVLNode<E> node, TreeList.AVLNode<E> previous) Sets the left field to the node, or the previous node if that is nullprivate int
setOffset
(TreeList.AVLNode<E> node, int newOffest) Sets the relative position.private void
setRight
(TreeList.AVLNode<E> node, TreeList.AVLNode<E> next) Sets the right field to the node, or the next node if that is null(package private) void
Sets the value.(package private) void
Stores the node and its children into the array specified.toString()
Used for debugging.
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Field Details
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left
The left child node or the predecessor ifleftIsPrevious
. -
leftIsPrevious
private boolean leftIsPreviousFlag indicating that left reference is not a subtree but the predecessor. -
right
The right child node or the successor ifrightIsNext
. -
rightIsNext
private boolean rightIsNextFlag indicating that right reference is not a subtree but the successor. -
height
private int heightHow many levels of left/right are below this one. -
relativePosition
private int relativePositionThe relative position, root holds absolute position. -
value
The stored element.
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Constructor Details
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AVLNode
private AVLNode(int relativePosition, E obj, TreeList.AVLNode<E> rightFollower, TreeList.AVLNode<E> leftFollower) Constructs a new node with a relative position.- Parameters:
relativePosition
- the relative position of the nodeobj
- the value for the noderightFollower
- the node with the value following this oneleftFollower
- the node with the value leading this one
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AVLNode
Constructs a new AVL tree from a collection.The collection must be nonempty.
- Parameters:
coll
- a nonempty collection
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AVLNode
private AVLNode(Iterator<? extends E> iterator, int start, int end, int absolutePositionOfParent, TreeList.AVLNode<E> prev, TreeList.AVLNode<E> next) Constructs a new AVL tree from a collection.This is a recursive helper for
AVLNode(Collection)
. A call to this method will construct the subtree for elementsstart
throughend
of the collection, assuming the iteratore
already points at elementstart
.- Parameters:
iterator
- an iterator over the collection, which should already point to the element at indexstart
within the collectionstart
- the index of the first element in the collection that should be in this subtreeend
- the index of the last element in the collection that should be in this subtreeabsolutePositionOfParent
- absolute position of this node's parent, or 0 if this node is the rootprev
- theAVLNode
corresponding to element (start - 1) of the collection, or null if start is 0next
- theAVLNode
corresponding to element (end + 1) of the collection, or null if end is the last element of the collection
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Method Details
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getValue
E getValue()Gets the value.- Returns:
- the value of this node
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setValue
Sets the value.- Parameters:
obj
- the value to store
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get
Locate the element with the given index relative to the offset of the parent of this node. -
indexOf
Locate the index that contains the specified object. -
toArray
Stores the node and its children into the array specified.- Parameters:
array
- the array to be filledindex
- the index of this node
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next
TreeList.AVLNode<E> next()Gets the next node in the list after this one.- Returns:
- the next node
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previous
TreeList.AVLNode<E> previous()Gets the node in the list before this one.- Returns:
- the previous node
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insert
Inserts a node at the position index.- Parameters:
index
- is the index of the position relative to the position of the parent node.obj
- is the object to be stored in the position.
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insertOnLeft
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insertOnRight
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getLeftSubTree
Gets the left node, returning null if its a faedelung. -
getRightSubTree
Gets the right node, returning null if its a faedelung. -
max
Gets the rightmost child of this node.- Returns:
- the rightmost child (greatest index)
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min
Gets the leftmost child of this node.- Returns:
- the leftmost child (smallest index)
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remove
Removes the node at a given position.- Parameters:
index
- is the index of the element to be removed relative to the position of the parent node of the current node.
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removeMax
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removeMin
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removeSelf
Removes this node from the tree.- Returns:
- the node that replaces this one in the parent
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balance
Balances according to the AVL algorithm. -
getOffset
Gets the relative position. -
setOffset
Sets the relative position. -
recalcHeight
private void recalcHeight()Sets the height by calculation. -
getHeight
Returns the height of the node or -1 if the node is null. -
heightRightMinusLeft
private int heightRightMinusLeft()Returns the height difference right - left -
rotateLeft
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rotateRight
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setLeft
Sets the left field to the node, or the previous node if that is null- Parameters:
node
- the new left subtree nodeprevious
- the previous node in the linked list
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setRight
Sets the right field to the node, or the next node if that is null- Parameters:
node
- the new left subtree nodenext
- the next node in the linked list
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addAll
Appends the elements of another tree list to this tree list by efficiently merging the two AVL trees. This operation is destructive to both trees and runs in O(log(m + n)) time.- Parameters:
otherTree
- the root of the AVL tree to merge with this onecurrentSize
- the number of elements in this AVL tree- Returns:
- the root of the new, merged AVL tree
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toString
Used for debugging.
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