Need help with a binary tree class

Trips · Nov 13, 2010

Hi, I have only been using C# for a short time now and am learning about binary trees and trying to develop one for an application.
The one that I have seems to work fine except for the moveTo method. I get an error message for each of the switch cases. The message is "The name leftChild does not exist in the current context" I get the same message for
rightChild, parent, and rootNode.
Does anyone have any ideas as to why I am getting this message and how I might fix it?
The code is as follows:
using System; 
using System.Collections; 
using System.Collections.Generic; 
using System.Collections.ObjectModel; 
using System.Linq; 
using System.Text; 
 
namespace _CSharpTestingGrounds 
{ 
public class BinaryTree<T> 
{ 
 
private Node<T> root; 
private Node<T> current; 
private int size; 
 
public enum Relative 
{ leftChild = 0, rightChild = 1, parent = 2, rootNode = 3 }; 
 
public BinaryTree() 
{ 
root = null; 
current = null; 
size = 0; 
} 
 
public void Destroy(Node<T> n) 
{ 
if (n != null) 
{ 
Destroy(n.getLeft()); 
Destroy(n.getRight()); 
n = null; 
size--; 
} 
} 
 
public bool isEmpty() 
{ 
return root == null; 
} 
 
public bool isLeaf() 
{ 
bool isLeaf = false; 
 
isLeaf = (current.getLeft() == null && current.getRight() == null); 
 
return isLeaf; 
} 
 
public int getSize() 
{ 
return size; 
} 
 
public T getCurrent() 
{ 
return current.getElement(); 
} 
 
private Node<T> findParent(Node<T> n) 
{ 
Stack<Node<T>> s = new Stack<Node<T>>(); 
n = root; 
while (n.getLeft() != current && n.getRight() != current) 
{ 
if (n.getRight() != null) 
s.Push(n.getRight()); 
 
if (n.getLeft() != null) 
n = n.getLeft(); 
else 
n = s.Pop(); 
} 
s.Clear(); 
return n; 
} 
 
public bool moveTo(Relative rel) 
{ 
bool found = false; 
 
switch (rel) 
{ 
case leftChild: 
if (current.getLeft() != null) 
{ 
current = current.getLeft(); 
found = true; 
} 
break; 
case rightChild: 
if (current.getRight() != null) 
{ 
current = current.getRight(); 
found = true; 
} 
break; 
case parent: 
if (current != root) 
{ 
current = findParent(current); 
found = true; 
} 
break; 
case rootNode: 
if (root != null) 
{ 
current = root; 
found = true; 
} 
break; 
} // end Switch relative 
 
return found; 
} 
 
public Node<T> getRoot() 
{ 
return root; 
} 
 
public void Update(T el) 
{ 
current.setElement(el); 
} 
 
public bool insert(T value, Relative rel) 
{ 
bool inserted = true; 
 
Node<T> node = null; 
 
if ((rel == BinaryTree<T>.Relative.leftChild && current.getLeft() != null) 
|| (rel == BinaryTree<T>.Relative.rightChild && current.getRight() != null)) 
{ 
inserted = false; 
} 
else 
{ 
 
node = new Node<T>(value); 
 
switch (rel) 
{ 
case leftChild: 
current.setLeft(node); 
break; 
case rightChild: 
current.setRight(node); 
break; 
case rootNode: 
if (root == null) 
root = node; 
current = root; 
break; 
} 
} 
 
size++; 
 
return inserted; 
} 
 
public void inOrder(Node<T> p) 
{ 
if (p != null) 
{ 
inOrder(p.getLeft()); 
Console.Write(p.getElement().ToString()); 
inOrder(p.getRight()); 
} 
} 
 
public void preOrder(Node<T> p) 
{ 
if (p != null) 
{ 
Console.Write(p.getElement().ToString()); 
preOrder(p.getLeft()); 
preOrder(p.getRight()); 
} 
} 
 
public void postOrder(Node<T> p) 
{ 
if (p != null) 
{ 
postOrder(p.getLeft()); 
postOrder(p.getRight()); 
Console.Write(p.getElement().ToString()); 
} 
} 
 
} 
} 

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Need help with a binary tree class

Trips

Well-known member

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