nz.ac.waikato.jdsl.core.ref
Class PreOrderIterator

java.lang.Object
  nz.ac.waikato.jdsl.core.ref.PreOrderIterator

All Implemented Interfaces:

ObjectIterator, PositionIterator

public class PreOrderIterator
extends java.lang.Object
implements PositionIterator

The preorder iterator gives a preorder iteration of the tree. Creating this iterator takes O(N) where N = the number of positions in the tree, assuming that root, rightChild, leftChild, isInternal are O(1) in the tree implementation. All other methods take O(1) time.

Version:

JDSL 2.1.1

Author:

Ryan Shaun Baker

Constructor Summary

PreOrderIterator(InspectableBinaryTree tree)
Constructs a new PreOrderIterator to iterate over the given binary tree Puts a reference to each position into the array -- takes O(N) time where N = the number of positions in the tree

PreOrderIterator(InspectableTree tree)
Constructs a new PreOrderIterator to iterate over the given general tree Puts a reference to each position into the array -- takes O(N) time where N = the number of positions in the tree

Method Summary

java.lang.Object	element() Takes O(1) time
boolean	hasNext() Takes O(1) time
java.lang.Object	nextObject()
Position	nextPosition() Takes O(1) time
java.lang.Object	object()
Position	position() Takes O(1) time
void	reset() Takes O(1) time Sets the current node to the first node.

Methods inherited from class java.lang.Object

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

Constructor Detail

PreOrderIterator

public PreOrderIterator(InspectableBinaryTree tree)

Constructs a new PreOrderIterator to iterate over the given binary tree Puts a reference to each position into the array -- takes O(N) time where N = the number of positions in the tree

Parameters:

tree - The tree to iterate over

PreOrderIterator

public PreOrderIterator(InspectableTree tree)

Constructs a new PreOrderIterator to iterate over the given general tree Puts a reference to each position into the array -- takes O(N) time where N = the number of positions in the tree

Parameters:

tree - The tree to iterate over

Method Detail

hasNext

public boolean hasNext()

Takes O(1) time

Specified by:

hasNext in interface ObjectIterator

Returns:

Whether there is at least one object still unseen

nextObject

public java.lang.Object nextObject()

Specified by:

nextObject in interface ObjectIterator

Returns:

Next object to consider

object

public java.lang.Object object()

Specified by:

object in interface ObjectIterator

Returns:

The object returned by the most recent next()

reset

public void reset()

Takes O(1) time Sets the current node to the first node.

Specified by:

reset in interface ObjectIterator

nextPosition

public Position nextPosition()

Takes O(1) time

Specified by:

nextPosition in interface PositionIterator

Returns:

Next position to consider

position

public Position position()
                  throws java.util.NoSuchElementException

Takes O(1) time

Specified by:

position in interface PositionIterator

Returns:

The position returned by the most recent next()

Throws:

java.util.NoSuchElementException - When the iterator is in its initial, before-the-first-position state

element

public java.lang.Object element()
                         throws java.util.NoSuchElementException

Takes O(1) time

Specified by:

element in interface PositionIterator

Returns:

Element of the position that would be returned by position()

Throws:

java.util.NoSuchElementException - When the iterator is in its initial, before-the-first-position state