[chaoxu]

I was a TA in a few undergraduate algorithms classes in at UIUC. This level of problems can show up in the exams. Although I hold UIUC students in high regard, certainly we don't expect undergrads to be "faculty-level algorithm specialist."

The discovery of many things is done by people with a genius-level intellect. Like calculus, probability, etc. but I can certainly ask mechanical engineers calculus problems, or data scientist probability problems.

It is certainly difficult for someone who never seen anything related to it. But for people who had the background, it is not unreasonable. I think this kind of problem is biased toward people who

1. had a good (theoretical) CS education, or 2. solved lots of leetcode problems so they can just do "pattern matching".