private AvlNode Find(int target, AvlNode current)
{
if (target < current.data)
{
if (target == current.data)
{
return(current);
}
return(Find(target, current.left));
}
if (target == current.data)
{
return(current);
}
return(Find(target, current.right));
}
private AvlNode RecursiveInsert(AvlNode current, AvlNode n)
{
if (current == null)
{
current = n;
return(current);
}
if (n.data < current.data)
{
current.left = RecursiveInsert(current.left, n);
current = balance_tree(current);
}
else if (n.data > current.data)
{
current.right = RecursiveInsert(current.right, n);
current = balance_tree(current);
}
return(current);
}
private AvlNode Delete(AvlNode current, int target)
{
AvlNode parent;
if (current == null)
{
return(null);
}
//left subtree
if (target < current.data)
{
current.left = Delete(current.left, target);
if (balance_factor(current) == -2) //here
{
if (balance_factor(current.right) <= 0)
{
current = RotateRR(current);
}
else
{
current = RotateRL(current);
}
}
}
//right subtree
else if (target > current.data)
{
current.right = Delete(current.right, target);
if (balance_factor(current) == 2)
{
if (balance_factor(current.left) >= 0)
{
current = RotateLL(current);
}
else
{
current = RotateLR(current);
}
}
}
//if target is found
else
{
if (current.right != null)
{
//delete its inorder successor
parent = current.right;
while (parent.left != null)
{
parent = parent.left;
}
current.data = parent.data;
current.right = Delete(current.right, parent.data);
if (balance_factor(current) == 2) //rebalancing
{
if (balance_factor(current.left) >= 0)
{
current = RotateLL(current);
}
else
{
current = RotateLR(current);
}
}
}
else
{
//if current.left != null
return(current.left);
}
}
return(current);
}
public void Delete(int target)
{
//and here
root = Delete(root, target);
}