What are the techniques for balancing AVL trees?

What are the techniques for balancing AVL trees?

AVL trees use rotations to maintain balance. The main techniques are single rotations (left or right) and double rotations (left-right or right-left).

Can you explain how single rotations work?

Sure! A single rotation is performed when a node becomes unbalanced due to an insertion in its left or right subtree. For example, a right rotation is used when a node's left child is taller.

What about double rotations? When are they used?

Double rotations are used when a node's left child has a right-heavy subtree or vice versa. They involve two rotations: first a single rotation on the child, followed by a single rotation on the unbalanced node.

Are there any specific cases where these techniques are particularly useful?

Yes, single rotations are useful for simple imbalances, while double rotations are essential for more complex cases, ensuring the tree remains balanced after insertions.