##AVL Tree

###This is a self-balancing binary search tree

According to Wikipedia, an AVL tree , named after inventors Adelson-Velsky and Landis is a self-balancing binary search tree. The heights of the two child subtrees of any node differ by at most one; if at any time they differ by more than one, rebalancing is done to restore this property.

BalanceFactor = Heigh of Right Subtree - Height of Left subtree

Insertion

Whenever a node insertion happens, the tree rotates based on the BalanceFactor, thereby adding the new node to the best place where the tree is most balanced.

Rotation

There are two types of rotations - single rotation and double rotation