I have a basic algorithm below and I know that the worst case input BST is one that has degenerated to a linked list from inserts to only one side.

How would I compute the worst case complexity in terms of number of rotations for this BST to AVL conversion algorithm?

IF tree is right heavy
{
  IF tree's right subtree is left heavy
  {
     Perform Double Left rotation 
  }
  ELSE
  {
     Perform Single Left rotation
  }
}
ELSE IF tree is left heavy
{
  IF tree's left subtree is right heavy
  {
     Perform Double Right rotation
  }
  ELSE
  {
     Perform Single Right rotation
  }
}