Common Mistakes

• Confusing search and startsWith: Search requires isEndOfWord check; startsWith only checks path existence.
• Memory overhead with array children: Using $26$-element arrays wastes memory. Hash maps are more space-efficient for sparse alphabets.
• Not marking word boundaries: Forgetting isEndOfWord flag means "app" matches when only "apple" was inserted.
• Case sensitivity: Decide upfront if trie is case-sensitive.

Normalize input if case-insensitive.