EmptyTree

java.lang.Object
- tree.EmptyTree<K,V>

All Implemented Interfaces:

Tree<K,V>
```
public class EmptyTree<K extends java.lang.Comparable<K>,V>
extends java.lang.Object
implements Tree<K,V>
```
This class is used to represent the empty search tree: a search tree that contains no entries. This class is a singleton class: since all empty search trees are the same, there is no need for multiple instances of this class. Instead, a single instance of the class is created and made available through the static field SINGLETON. The constructor is private, preventing other code from mistakenly creating additional instances of the class.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addKeysToCollection(java.util.Collection<K> c)` Add all keys bound in this tree to the collection c.
`Tree<K,V>`	`delete(K key)` Delete any binding the key has in this tree.
`static <K extends java.lang.Comparable<K>,V> EmptyTree<K,V>`	`getInstance()`
`int`	`height()` Returns the height (maximum level) in the tree.
`void`	`inorderTraversal(TraversalTask<K,V> p)` Performs the specified task on the tree using an inorder traversal.
`NonEmptyTree<K,V>`	`insert(K key, V value)` Insert/update the Tree with a new key:value pair.
`K`	`max()` Return the maximum key in the subtree
`K`	`min()` Return the minimum key in the subtree
`void`	`rightRootLeftTraversal(TraversalTask<K,V> p)` Performs the specified task on the tree using a right tree, root, left tree traversal.
`V`	`search(K key)` Find the value that this key is bound to in this tree.
`int`	`size()` Return number of keys that are bound in this tree.
`Tree<K,V>`	`subTree(K fromKey, K toKey)` Returns a Tree containing all entries between fromKey and toKey, inclusive.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getInstance
```
public static <K extends java.lang.Comparable<K>,V> EmptyTree<K,V> getInstance()
```
  - search
```
public V search(K key)
```
    Description copied from interface: Tree
    
    Find the value that this key is bound to in this tree.
    
    Specified by:
    
    search in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    key - -- Key to search for
    
    Returns:
    -- value associated with the key by this Tree, or null if the key does not have an association in this tree.
  - insert
```
public NonEmptyTree<K,V> insert(K key,
                       V value)
```
    Description copied from interface: Tree
    
    Insert/update the Tree with a new key:value pair. If the key already exists in the tree, update the value associated with it. If the key doesn't exist, insert the new key value pair. This method returns a reference to an Tree that represents the updated value. In many, but not all cases, the method may just return a reference to this. This method is annotated @CheckReturnValue because you have to pay attention to the return value; if you simply invoke insert on a Tree and ignore the return value, your code is almost certainly wrong.
    
    Specified by:
    
    insert in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    key - -- Key
    value - -- Value that the key maps to
    
    Returns:
    -- updated tree
  - delete
```
public Tree<K,V> delete(K key)
```
    Description copied from interface: Tree
    
    Delete any binding the key has in this tree. If the key isn't bound, this is a no-op This method returns a reference to an Tree that represents the updated value. In many, but not all cases, the method may just return a reference to this. This method is annotated @CheckReturnValue because you have to pay attention to the return value; if you simply invoke delete on a Tree and ignore the return value, your code is almost certainly wrong.
    
    Specified by:
    
    delete in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    key - -- Key
    
    Returns:
    -- updated tree
  - max
```
public K max()
                                      throws TreeIsEmptyException
```
    Description copied from interface: Tree
    
    Return the maximum key in the subtree
    
    Specified by:
    
    max in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Returns:
    maximum key
    
    Throws:
    
    TreeIsEmptyException - if the tree is empty
  - min
```
public K min()
                                      throws TreeIsEmptyException
```
    Description copied from interface: Tree
    
    Return the minimum key in the subtree
    
    Specified by:
    
    min in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Returns:
    minimum key
    
    Throws:
    
    TreeIsEmptyException - if the tree is empty
  - size
```
public int size()
```
    Description copied from interface: Tree
    
    Return number of keys that are bound in this tree.
    
    Specified by:
    
    size in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Returns:
    number of keys that are bound in this tree.
  - addKeysToCollection
```
public void addKeysToCollection(java.util.Collection<K> c)
```
    Description copied from interface: Tree
    
    Add all keys bound in this tree to the collection c. The elements can be added in any order.
    
    Specified by:
    
    addKeysToCollection in interface Tree<K extends java.lang.Comparable<K>,V>
  - subTree
```
public Tree<K,V> subTree(K fromKey,
                K toKey)
```
    Description copied from interface: Tree
    
    Returns a Tree containing all entries between fromKey and toKey, inclusive. It may not modify the original tree (a common mistake while implementing this method).
    
    Specified by:
    
    subTree in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    fromKey - - Lower bound value for keys in subtree
    toKey - - Upper bound value for keys in subtree
    
    Returns:
    Tree containing all entries between fromKey and toKey, inclusive
  - height
```
public int height()
```
    Description copied from interface: Tree
    
    Returns the height (maximum level) in the tree. A tree with only one entry has a height of 1.
    
    Specified by:
    
    height in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Returns:
    height of the tree.
  - inorderTraversal
```
public void inorderTraversal(TraversalTask<K,V> p)
```
    Description copied from interface: Tree
    
    Performs the specified task on the tree using an inorder traversal.
    
    Specified by:
    
    inorderTraversal in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    p - object defining task
  - rightRootLeftTraversal
```
public void rightRootLeftTraversal(TraversalTask<K,V> p)
```
    Description copied from interface: Tree
    
    Performs the specified task on the tree using a right tree, root, left tree traversal.
    
    Specified by:
    
    rightRootLeftTraversal in interface Tree<K extends java.lang.Comparable<K>,V>
    
    Parameters:
    p - object defining task

Class EmptyTree<K extends java.lang.Comparable<K>,V>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getInstance

search

insert

delete

max

min

size

addKeysToCollection

subTree

height

inorderTraversal

rightRootLeftTraversal