Table of Contents
- 1 What type of rotation do you need to rebalance an AVL tree?
- 2 What is double rotation in AVL tree?
- 3 What is the balance factor of AVL tree?
- 4 What are different methods to perform rotations in an AVL tree?
- 5 What is the balancing condition of an AVL tree?
- 6 What is the difference between RL rotation and AVL tree?
- 7 What is the height of an AVL tree after insertion?
What type of rotation do you need to rebalance an AVL tree?
right rotation
AVL tree may become unbalanced, if a node is inserted in the left subtree of the left subtree. The tree then needs a right rotation. As depicted, the unbalanced node becomes the right child of its left child by performing a right rotation.
What are the different rotations can be performed on AVL tree to make it balance explain all with examples?
AVL Insertion Process
- If there is an imbalance in the left child’s right sub-tree, perform a left-right rotation.
- If there is an imbalance in the left child’s left sub-tree, perform a right rotation.
- If there is an imbalance in the right child’s right sub-tree, perform a left rotation.
What is double rotation in AVL tree?
The key to an AVL tree is keeping it balanced when an insert or delete operation is performed. If we start with an AVL tree, then what is needed is either a single rotation or a double rotation (which is two single rotations) on the unbalanced node and that will always restore the balance property in O(1) time.
How many rotation operations are there in AVL tree?
There are basically four types of rotations which are as follows: L L rotation: Inserted node is in the left subtree of left subtree of A. R R rotation : Inserted node is in the right subtree of right subtree of A. L R rotation : Inserted node is in the right subtree of left subtree of A.
What is the balance factor of AVL tree?
Properties of an AVL tree: The balance factor of a node is the height of its right subtree minus the height of its left subtree and a node with a balance factor 1, 0, or -1 is considered balanced.
What is the balancing condition of an AVL tree Mcq?
Explanation: It is a self balancing tree with height difference atmost 1. Explanation: The property of AVL tree is it is height balanced tree with difference of atmost 1 between left and right subtrees. All AVL trees are binary search tree.
What are different methods to perform rotations in an AVL tree?
Rotation Techniques
- Right Rotation. A single rotation applied when a node is inserted in the left subtree of a left subtree.
- Left Rotation. A single rotation applied when a node is inserted in the right subtree of a right subtree.
- Left-Right Rotation.
- Right-Left Rotation.
Why do we need to rotate trees?
A tree rotation moves one node up in the tree and one node down. It is used to change the shape of the tree, and in particular to decrease its height by moving smaller subtrees down and larger subtrees up, resulting in improved performance of many tree operations.
What is the balancing condition of an AVL tree?
balance(n) = abs(height(n.left)−height(n.right)) Definition (AVL Balance Property) An AVL tree is balanced when: For every node n, balance(n) ≤ 1.
How do you determine the balance factor of an AVL tree?
How to Calculate AVL Tree Balance Factor?
- Balance factor = height of left subtree – height of right subtree.
- Left-Left Rotation.
- Right-Right Rotation.
- Left Right Rotation.
- Right Left Rotation.
What is the difference between RL rotation and AVL tree?
In RL Rotation, first every node moves one position to right then one position to left from the current position. AVL tree is binary search tree with additional property that difference between height of left sub-tree and right sub-tree of any node can’t be more than 1.
What is the balance factor in AVL trees?
In AVL trees, after each operation like insertion and deletion, the balance factor of every node needs to be checked. If every node satisfies the balance factor condition, then the operation can be concluded. Otherwise, the tree needs to be rebalanced using rotation operations.
What is the height of an AVL tree after insertion?
The height of an AVL tree is always O (Logn) where n is the number of nodes in the tree (See this video lecture for proof). To make sure that the given tree remains AVL after every insertion, we must augment the standard BST insert operation to perform some re-balancing.
What is left and right rotation in aavl?
AVL Tree Left – Left Rotation A single right rotation is performed. This type of rotation is identified when a node has a balanced factor as +2, and its left-child has a balance factor as +1. Right – Right Rotation