For candidates who are fresh graduates, it looks it is the most effective way to ask algo and data structures. For a senior engineer who has at least 10 years of experiences, the interviewers cannot find some better questions to ask, to verify if the candidate is a good coder?
I was interviewed once. I was asked a question. I knew the question could be solved with a "fancy" algorithm, since I read the original paper in graduate school. It was elegant and beautiful, very creative. After so many years, I couldn't remember any details, and I had had no opportunity to use it in my work. I am not a genius, so I couldn't figure it out in 20 minutes during interview. Does that mean I am a fake?