Backstory: Autocomplete with trie tutorial teaches how to implement trie and use it to solve automcomplete problem, a popular interview question. This is a question from Amazon for software engineer position. The interviewer specifically asks to use trie.
Why I picked this question: When I studied Computer Science in college and graduate school, trie was not in textbook yet. Now it becomes a popular data structure you must know. You have to keep learning to survive as software engineer.