There are only two ways that a tree, or any subtree of a tree, can become unbalanced: through the insertion of a node or through the deletion of a node.

Question

Quizplus · Accepted Answer

The balance of a tree or any of its subtrees can only be altered by either inserting a new node, which may cause a previously balanced tree to become unbalanced if the new node is added in a way that disrupts the balance, or by deleting a node, which can remove a critical element that maintained the balance, thus potentially leading to an imbalance.

There Are Only Two Ways That a Tree, or Any