[tekkk]

You'd think so, but from my experience the folk that are very interested in algorithmic design and so forth produce highly abstract and hard to understand solutions to simple problems, which, in the end, are the majority in the regular dev work.

Sure if you're applying for a job that really demands algorithmic design skills it should be a great asset but in general the most valuable skills any programmer has is producing simple and robust code that works and others can continue building on. I don't deny that knowing algorithmic design skills well helps a lot but it does seem to feed the egos of the programmers to produce overly complicated solutions.

[teachingassist]

This is a nice point -

I'd answer this type of algorithm question in truth by identifying the relevant library wherever possible, not by coding it myself, and I'd strongly expect anyone I was working with to do the same.

[water8]

"I always code my own AES libraries because I'm an expert" - said no expert ever.