Class RedBlackTree<T>
- java.lang.Object
-
- org.apache.uima.internal.util.rb_trees.RedBlackTree<T>
-
- All Implemented Interfaces:
Iterable<T>
public class RedBlackTree<T> extends Object implements Iterable<T>
Map from int to T (Object) An implementation of Red-Black Trees. This implementation follows quite closely the algorithms described in Cormen, Leiserson and Rivest (1990): "Introduction to Algorithms" (henceforth CLR). The main difference between our implementation and CLR is that our implementation does not allow duplicate keys in a tree. Since we will generally use our implementation to represent sets, this is a sensible restriction.The difference between this implementation and
TreeMap
is that we assume that keys are ints. This should provide for a constant factor speed-up. We also assume that we may copy this implementation to specialize for particular data element types.This class implements most methods required for a
Map
. However, since we use ints as keys, we can't implement the interface, as ints are not Objects, and so for exampleRedBlackTree.containsKey(int key)
does not specializeMap.containsKey(Object key)
.Note that this implementation is not thread-safe. A thread-safe version could easily be provided, but would come with additional overhead.
-
-
Constructor Summary
Constructors Constructor Description RedBlackTree()
Default constructor, does nothing.
-
Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Remove all elements from the tree.boolean
containsKey(int key)
Checks if the key is contained in the tree.boolean
containsValue(T o)
Check if the value object is contained in the tree.T
get(int key)
Get the object for a key.BinaryTree
getBinaryTree()
T
getFirst()
boolean
isEmpty()
Check if the map is empty.Iterator<T>
iterator()
int[]
keySet()
Return the set of keys as a sorted array.static void
main(String[] args)
void
printKeys()
Debugging aid.boolean
put(int key, T el)
Insert an object with a given key into the tree.T
remove(int key)
Delete the node with the given key from the tree, if it exists.int
size()
-
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
-
Methods inherited from interface java.lang.Iterable
forEach, spliterator
-
-
-
-
Method Detail
-
size
public final int size()
- Returns:
- The number of key/value pairs in the tree.
-
clear
public final void clear()
Remove all elements from the tree.
-
containsKey
public final boolean containsKey(int key)
Checks if the key is contained in the tree.- Parameters:
key
- The key.- Returns:
true
, if key is defined;false
, else.
-
containsValue
public final boolean containsValue(T o)
Check if the value object is contained in the tree. Inefficient, since it requires a traverse of the tree.- Parameters:
o
- The value we want to check.- Returns:
true
, if value is there;false
, else.
-
put
public final boolean put(int key, T el)
Insert an object with a given key into the tree.- Parameters:
key
- The key under which the Object is to be inserted.el
- The Object to be inserted.- Returns:
true
, if the key was not in the tree;false
, if an element with that key was already in the tree. The old element is overwritten with the new one.
-
remove
public final T remove(int key)
Delete the node with the given key from the tree, if it exists.- Parameters:
key
- The key to be deleted.- Returns:
- -
-
get
public final T get(int key)
Get the object for a key. If the key is not contained in the tree, returnsnull
. Sincenull
can also be a regular value, usecontainsKey()
to check if a key is defined or not.- Parameters:
key
- The key.- Returns:
- The corresponding element, or
null
if key is not defined.
-
isEmpty
public final boolean isEmpty()
Check if the map is empty.- Returns:
true
if map is empty;false
, else.
-
keySet
public final int[] keySet()
Return the set of keys as a sorted array.- Returns:
- A sorted array of the keys.
-
getFirst
public final T getFirst()
- Returns:
- The object associated with the smallest key, or
null
if the tree is empty.
-
getBinaryTree
public BinaryTree getBinaryTree()
- Returns:
- a copy of the red-black tree as a BinaryTree. The node values are key-value pairs (RBTKeyValuePair).
-
printKeys
public void printKeys()
Debugging aid.
-
main
public static void main(String[] args)
-
-