Explain 'Trie' (Prefix Tree) deletion.

Explain 'Trie' (Prefix Tree) deletion.

Approach: Describe the recursive cleanup of nodes after removing a word.

Unmark the end-of-word flag. If the node has no children and is not the end of another word, delete it and recurse upwards to its parent.

Follow-up: What happens if the word to delete is a prefix of another word?

Key concepts: end-of-word marker, node cleanup.