# AVL tree

In

computer science, an

**AVL tree** is a

self-balancing binary search tree where the height of the two

child subtrees of any node differ by at most one, otherwise known as height-balanced. Look-up, insertion and deletion are all

O(log(

*n*)) in both the average and worst cases. Additions and deletions may require the tree to be rebalanced by one or more tree rotations. The AVL tree is named after its inventors, Adelson-Velskii and Landis (

1962).

See also: B-tree, red-black tree, splay tree