I am pretty sure (and given this is HN I'm sure a googler will be along soon to confirm/deny this) that Google have a policy of no longer asking those kind of b

I am pretty sure (and given this is HN I'm sure a googler will be along soon to confirm/deny this) that Google have a policy of no longer asking those kind of brain-teasers for their software engineering roles. They may still do so for PMs, etc. Certainly when I had my Google on-site for an engineering role I was spared the infamous questions that crop up in articles like this from time to time.