LinkedIn Sr. Software Engineer interview questions

I got a call from recruiter for technical phone screen round. She mentioned I would be expected to solve two DSA questions. I was asked 1 dsa question , Find leaves of binary tree leetcode question. I was able to give optimal approach in 15 min. Interviewer didn’t understand it and went on to ask about 1NF, diff between unqiue key and primary key and indexing. He also asked another coding question in last 10 min. I was able to give answer to the first part.