blogspot.software_and_algorithms.stern_library.data_structure

Class RedBlackTree<T>

java.lang.Object

blogspot.software_and_algorithms.stern_library.data_structure.RedBlackTree<T>

All Implemented Interfaces:

Iterable<T>

Direct Known Subclasses:

OrderLinkedRedBlackTree

public class RedBlackTree<T>
extends Object
implements Iterable<T>

A red-black tree is a binary search tree guaranteeing that no path from root to leaf is more than twice as long as any other such path. This property provides an assurance that the height of a red-black tree is logarithmic in the number of nodes in the tree.

This implementation is based upon Cormen, Leiserson, Rivest, Stein's Introduction to Algorithms book.

See Also:

"Introduction to Algorithms Cormen, Leiserson, Rivest, and Stein. Introduction to Algorithms. 2nd ed. Cambridge, MA: MIT Press, 2001. ISBN: 0262032937."

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RedBlackTree.Node<T> A red-black tree node is a binary tree node augmented to hold an additional piece of information called the node's color.

Constructor Summary

Constructors

Constructor and Description
RedBlackTree() Default constructor.
RedBlackTree(Comparator<? super T> comparator) Construct a new tree which uses the specified custom comparator.

Method Summary

Modifier and Type	Method and Description
void	clear() Clear all entries from this tree.
boolean	contains(T value) Test whether or not the specified value is an element of this tree.
protected RedBlackTree.Node<T>	createNewNode(T value) Create a new node with the specified value.
RedBlackTree.Node<T>	delete(T value) Delete the specified value from this tree.
protected void	exchangeValues(RedBlackTree.Node<T> node, RedBlackTree.Node<T> successor) Called by delete(T) when the node to be removed is a leaf.
protected void	fixAfterDeletion(RedBlackTree.Node<T> node) Re-balance the tree after a delete operation.
protected void	fixAfterInsertion(RedBlackTree.Node<T> node) Re-balance the tree after an insert operation.
RedBlackTree.Node<T>	getFirstNode() Get the node containing the smallest value held by this tree.
RedBlackTree.Node<T>	getNode(T value) Get the node that holds the specified value.
RedBlackTree.Node<T>	getPredecessor(RedBlackTree.Node<T> node) Get the predecessor of the specified node.
RedBlackTree.Node<T>	getRoot() Get the root of this tree.
int	getSize() Get the number of elements contained within this tree.
RedBlackTree.Node<T>	getSuccessor(RedBlackTree.Node<T> node) Get the successor of the specified node.
RedBlackTree.Node<T>	insert(T value) Insert the specified value into this tree.
boolean	isEmpty()
Iterator<T>	iterator() Returns an Iterator over the elements of this tree.
protected void	leftRotate(RedBlackTree.Node<T> node) Perform a left rotate operation on the specified node.
protected void	rightRotate(RedBlackTree.Node<T> node) Perform a right rotate operation on the specified node.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

RedBlackTree

public RedBlackTree()

Default constructor. Tree uses the natural ordering of elements defined by Comparable.compareTo(Object); for custom ordering see RedBlackTree(Comparator).

RedBlackTree

public RedBlackTree(Comparator<? super T> comparator)

Construct a new tree which uses the specified custom comparator.

Parameters:

comparator - the comparator to use when ordering elements.

Method Detail

clear

public void clear()

Clear all entries from this tree.

contains

public boolean contains(T value)

Test whether or not the specified value is an element of this tree.

Parameters:

value - the query value.

Returns:

true if the specified value is an element of this tree, false otherwise.

createNewNode

protected RedBlackTree.Node<T> createNewNode(T value)

Create a new node with the specified value. This method allows a subclass to assert control over the type of the nodes held by this tree.

Parameters:

value - the value to apply to the new node.

Returns:

a new node holding the specified value.

delete

public RedBlackTree.Node<T> delete(T value)

Delete the specified value from this tree.

Parameters:

value - the value to delete.

Returns:

the node which contained the value before it was removed from this tree, null if the value is not an element of this tree.

exchangeValues

protected void exchangeValues(RedBlackTree.Node<T> node,
                              RedBlackTree.Node<T> successor)

Called by delete(T) when the node to be removed is a leaf. In this case, the node's value is exchanged with its successor as per the typical binary tree node removal operation. This method allows a subclass to influence value exchange behavior (e.g. if additional node information needs to be exchanged).

Parameters:

node - the node whose value is to be removed.

successor - the node to actually be removed.

fixAfterDeletion

protected void fixAfterDeletion(RedBlackTree.Node<T> node)

Re-balance the tree after a delete operation.

Parameters:

node - the deleted node or the swap node.

See Also:

"CLRS Introduction to Algorithms"

fixAfterInsertion

protected void fixAfterInsertion(RedBlackTree.Node<T> node)

Re-balance the tree after an insert operation.

Parameters:

node - the inserted node.

See Also:

"CLRS Introduction to Algorithms"

getFirstNode

public RedBlackTree.Node<T> getFirstNode()

Get the node containing the smallest value held by this tree.

Returns:

the node containing the smallest value held by this tree.

getNode

public RedBlackTree.Node<T> getNode(T value)

Get the node that holds the specified value.

Parameters:

value - the query value.

Returns:

the node that holds the specified value, null if none.

getPredecessor

public RedBlackTree.Node<T> getPredecessor(RedBlackTree.Node<T> node)

Get the predecessor of the specified node. The predecessor of a node n is the node with the largest value in the tree smaller than the value held by n.

Parameters:

node - the node compared to which predecessor node will be found

Returns:

the predecessor of the specified node

See Also:

"CLRS"

getRoot

public RedBlackTree.Node<T> getRoot()

Get the root of this tree.

Returns:

the root of this tree.

getSize

public int getSize()

Get the number of elements contained within this tree.

Returns:

the number of elements contained within this tree.

getSuccessor

public RedBlackTree.Node<T> getSuccessor(RedBlackTree.Node<T> node)

Get the successor of the specified node. The successor of a node n is the node with the smallest value in the tree larger than the value held by n.

Parameters:

node - the node compared to which successor node will be found

Returns:

the successor of the specified node

See Also:

"CLRS"

insert

public RedBlackTree.Node<T> insert(T value)

Insert the specified value into this tree.

Parameters:

value - the value to insert.

Returns:

the new node containing the specified value if the value was not already present in the tree, null otherwise.

isEmpty

public boolean isEmpty()

Returns:

true if there are no items in this tree, false otherwise.

iterator

public Iterator<T> iterator()

Returns an Iterator over the elements of this tree.

Specified by:

iterator in interface Iterable<T>

Returns:

an Iterator over the elements of this tree.

leftRotate

protected void leftRotate(RedBlackTree.Node<T> node)

Perform a left rotate operation on the specified node.

Parameters:

node - the node on which the left rotate operation will be performed.

See Also:

"CLRS Introduction to Algorithms"

rightRotate

protected void rightRotate(RedBlackTree.Node<T> node)

Perform a right rotate operation on the specified node.

Parameters:

node - the node on which a right rotate operation is to be performed.

See Also:

"CLRS Introduction to Algorithms"

toString

public String toString()

Overrides:

toString in class Object