Implement the trie with all three operations. Design choices: - Hash map vs. array for children: Hash map is flexible (any character set).
Array is faster for fixed alphabets (constant-time child lookup). - Separate class for node: Cleaner code, easier to extend with additional fields.
Testing checklist: - Insert and search same word - Search for prefix of existing word (should return false) - startsWith for prefix of existing word (should return true) - Search/startsWith for non-existent strings Time: for all operations. Space: .