public void Insert(int value)
{
root = InsertHelper(root, value);
}
private int Balance(AVLNode node)
{
return((node != null) ? Height(node.Left) - Height(node.Right) : 0);
}
private AVLNode RemoveHelper(AVLNode node, int value)
{
// Binary Search Tree deletion
if (node == null)
{
return(node);
}
if (value < node.Value)
// Node is in left subtree
{
node.Left = RemoveHelper(node.Left, value);
}
else if (value > node.Value)
// Node is in right subtree
{
node.Right = RemoveHelper(node.Right, value);
}
else
// Here we are
{
if ((node.Left == null) || (node.Right == null))
// Node with one child
{
AVLNode temp = null;
if (temp == node.Left)
{
temp = node.Right;
}
else
{
temp = node.Left;
}
if (temp == null)
{
temp = node;
node = null;
}
else
{
node = temp;
}
}
else
// Node with two children
{
AVLNode temp = FindMin(node.Right);
node.Value = temp.Value;
node.Right = RemoveHelper(node.Right, temp.Value);
}
}
if (node == null)
{
return(node); // Tree had one node
}
node.Height = 1 + Max(Height(node.Left), Height(node.Right));
int balance = Balance(node);
if (balance > 1 && Balance(node.Left) >= 0)
// Left Left Case
{
return(RightRotation(node));
}
else if (balance > 1 && Balance(node.Left) < 0)
// Left Right Case
{
node.Left = LeftRotation(node.Left);
return(RightRotation(node));
}
else if (balance < -1 && Balance(node.Right) <= 0)
// Right Right Case
{
return(LeftRotation(node));
}
else if (balance < -1 && Balance(node.Right) > 0)
// Right Left Case
{
node.Right = RightRotation(node.Right);
return(LeftRotation(node));
}
return(node);
}
private int Height(AVLNode node)
{
return((node != null) ? node.Height : 0);
}
public void Remove(int value)
{
root = RemoveHelper(root, value);
}
