The heights of the left and right subtrees differ by at most 1. In this tutorial, you will understand the working of various operations of an avl-black tree with working code in C, C++, Java, and Python. 21.3 has balance factor either 1 or less than that. Although it does not have AVL it does talk extensively about Red-Black trees, which i if find easier. This means the height of the AVL tree is in the order of log(n). Updating the height and getting the balance factor also take constant time. By the way, if you are familiar with java, for me the book Data Structures and Algorithms in Java, by Lafore helped me a lot to understand data structures. AVL trees are height balanced binary search trees. The AVL Tree Rotations Tutorial By John Hargrove Version 1.0.1, Updated Mar-22-2007 Abstract I wrote this document in an effort to cover what I consider to be a dark area of the AVL Tree concept. Rather, the tree will be called AVL tree, if the balance factor of each node in a tree is 0, 1 or –1. 2-3-4 Tree is a self-balancing multiway search tree. An AVL tree is a binary search tree which has the following properties: ->The sub-trees of every node differ in height by at most one. AVL tree is a self-balancing binary search tree in which each node maintains an extra information called as balance factor whose value is either -1, 0 or +1. An AVL tree is a self-balancing binary search tree. You must be remembering that the condition for a tree to be an AVL tree, every node’s balance needs not to be zero necessarily. ->Every sub-tree is an AVL tree. In this tutorial, we'll look at the insertions and deletions in the 2-3-4 tree. So every node in the tree in fig. AVL tree checks the height of the left and the right sub-trees and assures that the difference is not more than 1. Though we don't use 2-3-4 trees in practice, we study them to understand the theory behind Red-Black trees. When presented with the task of writing an AVL tree class in Java, I was left scouring the web for useful information on how this all works. Preorder traversal of the constructed AVL tree is 9 1 0 -1 5 2 6 10 11 Preorder traversal after deletion of 10 1 0 -1 9 5 2 6 11 Time Complexity: The rotation operations (left and right rotate) take constant time as only few pointers are being changed there.