private Tuple <BinaryNode <int>, BinaryNode <int> > FindNode(int value, BinaryNode <int> node, BinaryNode <int> parent)
{
BinaryNode <int> target = null;
if (node != null)
{
if (value == node.value)
{
return(new Tuple <BinaryNode <int>, BinaryNode <int> >(node, parent));
}
else if (value > node.value)
{
return(FindNode(value, node.right, node));
}
else
{
return(FindNode(value, node.left, node));
}
}
else
{
return(null);
}
}
public bool RemoveNode(int value)
{
if (value < 0)
{
return(false);
}
bool found = false;
bool isRoot = false;
bool isRightChild = false;
BinaryNode <int> parent;
BinaryNode <int> target = FindWithParent(value, out parent);
BinaryNode <int> newNode = null;
BinaryNode <int> leftMostChildParent = null;
if (parent == null)
{
isRoot = true;
}
else
{
isRightChild = target.value > parent.value;
}
//if it has no right child
if (target.right == null)
{
//and it hasn't left too
if (target.left == null)
{
if (isRoot)
{
Root = null;
}
else
{
if (isRightChild)
{
parent.right = null;
}
else
{
parent.left = null;
}
}
found = true;
}
//the target has a left child only (no right of course)
else
{
if (isRoot)
{
Root = target.left;
}
else
{
if (isRightChild)
{
parent.right = target.left;
}
else
{
target.right.left = target.left;
}
}
found = true;
}
}
//has a right child
//it can have left child of course but our focus is on the right child
else
{
//that right child has a left child
if (target.right.left != null)
{
BinaryNode <int> leftMostChild = target.right;
//get most left child
while (leftMostChild.left.left != null)
{
leftMostChild = leftMostChild.left;
}
//to be able to get the parent of the left most child to remove it is pointer to our new target (which is its left child)
leftMostChildParent = leftMostChild;
leftMostChild = leftMostChild.left;
leftMostChildParent.left = null;
if (isRoot)
{
Root = leftMostChild;
Root.left = target.left;
Root.right = target.right;
}
else
{
if (isRightChild)
{
parent.right = leftMostChild;
parent.right.right = target.right;
parent.right.left = target.left;
}
else
{
parent.left = leftMostChild;
parent.left.right = target.right;
parent.left.left = target.left;
}
}
found = true;
}
//that right child doesn't have a left child
else
{
if (isRoot)
{
Root = target.right;
Root.left = target.left;
}
else
{
if (isRightChild)
{
parent.right = target.right;
parent.right.left = target.left;
}
else
{
//replace the node with its right child
parent.left = target.right;
//connects the node with any left child it was connected to before (parent.left is our new node)
parent.left.left = target.left;
}
}
found = true;
}
}
return(found);
}
/// <summary>
/// Constructor.
/// </summary>
public BinaryTree()
{
count = 0;
root = null;
}
private void myRoot(BinaryNode <T> root)
{
this.root = root;
}
private void Add(BinaryNode <T> newElement, BinaryNode <T> root)
{
if (root == null)
{
this.SetRoot(newElement);
count++;
this.root.SetPadre(null);
}
else
{
BinaryNode <T> binaryNode = this.root;
while (binaryNode != null)
{
int compare = newElement.Value.CompareTo(binaryNode.Value);
if (compare < 0)
{
BinaryNode <T> left = binaryNode.GetLeft();
if (left == null)
{
binaryNode.SetLeft(newElement);
binaryNode.GetLeft().SetPadre(binaryNode);
count++;
InsertBalance(binaryNode, 1);
return;
}
else
{
binaryNode = left;
}
}
else
{
if (compare > 0)
{
BinaryNode <T> right = binaryNode.GetRight();
if (right == null)
{
binaryNode.SetRight(newElement);
binaryNode.GetRight().SetPadre(binaryNode);
count++;
InsertBalance(binaryNode, -1);
return;
}
else
{
binaryNode = right;
}
}
else
{
binaryNode.Value = newElement.Value;
return;
}
}
}
}
}
public void Delete(int data)
{
Root = RecursivelyDelete(Root, data);
}
public AVLTree()
{
count = 0;
root = null;
}
public BinaryNode(K key, V value, BinaryNode left, BinaryNode right)
{
this.Record = new KeyValuePair <K, V>(key, value);
this.Left = left;
this.Right = right;
}
public bool Remove(K key)
{
BinaryNode parent = default(BinaryNode);
BinaryNode lastVisited = default(BinaryNode);
BinaryNode located = this.TraverseTo(this.root, key, out parent, out lastVisited);
if (located == null)
{
return(false);
}
else
{
if (parent == null)
{
if (this.NodeIsLeaf(this.root))
{
this.root = null;
}
else if (this.root.Left != null && this.root.Right != null)
{
this.TwoChildRemove(this.root);
}
else if (this.root.Left == null)
{
this.root = this.root.Right;
}
else
{
this.root = this.root.Left;
}
}
else
{
if (parent.Left != null && parent.Left.Record.Key.Equals(key))
{
if (this.NodeIsLeaf(located))
{
parent.Left = null;
}
else if (located.Left != null && located.Right != null)
{
this.TwoChildRemove(parent.Left);
}
else if (located.Left == null)
{
parent.Left = parent.Left.Right;
}
else
{
parent.Left = parent.Left.Left;
}
}
else
{
if (this.NodeIsLeaf(located))
{
parent.Right = null;
}
else if (located.Left != null && located.Right != null)
{
this.TwoChildRemove(parent.Right);
}
else if (located.Left == null)
{
parent.Right = parent.Right.Right;
}
else
{
parent.Right = parent.Right.Left;
}
}
}
this.Count--;
return(true);
}
}
public void Clear()
{
this.root = null;
this.Count = 0;
}
private BinaryNode TraverseTo(BinaryNode start, K key, out BinaryNode parent, out BinaryNode lastVisited)
{
BinaryNode previous = null;
BinaryNode current = start;
while ((current != null && !current.Record.Key.Equals(key)) && !this.NodeIsLeaf(current))
{
if (key.CompareTo(current.Record.Key) < 0)
{
if (current.Left == null)
{
break;
}
previous = current;
current = current.Left;
}
else
{
if (current.Right == null)
{
break;
}
previous = current;
current = current.Right;
}
}
parent = previous;
lastVisited = current;
if (current != null && current.Record.Key.Equals(key))
{
return(current);
}
else
{
return(null);
}
}