## How do you delete an element in AVL tree?

If the node which is to be deleted is present in the left sub-tree of the critical node, then L rotation needs to be applied else if, the node which is to be deleted is present in the right sub-tree of the critical node, the R rotation will be applied.

**How do I add and delete in AVL tree?**

The insert and delete operation require rotations to be performed after violating the balance factor. The time complexity of insert, delete, and search operation is O(log N). AVL trees follow all properties of Binary Search Trees. The left subtree has nodes that are lesser than the root node.

### How do you remove a leaf node in AVL tree?

1) Perform the normal BST deletion. 2) The current node must be one of the ancestors of the deleted node. Update the height of the current node. 3) Get the balance factor (left subtree height – right subtree height) of the current node.

**How do you add elements to AVL tree?**

The new node is added into AVL tree as the leaf node….Insertion.

SN | Rotation | Description |
---|---|---|

3 | LR Rotation | The new node is inserted to the right sub-tree of the left sub-tree of the critical node. |

4 | RL Rotation | The new node is inserted to the left sub-tree of the right sub-tree of the critical node. |

#### How do you delete a node from a binary tree?

Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

- Starting at the root, find the deepest and rightmost node in binary tree and node which we want to delete.
- Replace the deepest rightmost node’s data with the node to be deleted.
- Then delete the deepest rightmost node.

**Why we use AVL tree instead of BST?**

the reason behind using AVL instead of BST is to make sure the search time is O(logn) because if we use BST and insert the values in a decreasing or increasing order then the BST would be one sided and the search time will be O(n), but if we do that using AVL then the tree will balance itself using rotations.

## Which rotations are performed to balanced AVL tree?

A left rotation is performed by making B the new root node of the subtree. A becomes the left subtree of its right subtree B. The tree is now balanced.

**What is the balance factor of an AVL tree node?**

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.