[nl]

I've done the Google interview thing (had 5 interviews, got asked to do more, declined due to my wife taking another job), and I can confirm I had some (I think 4 or 5) of these questions.

In my interviews I generally started with a naive answer, got the good answer on my own and got to the best answer with some hints from the interviewer. They didn't seem to regard this as a bad thing.

At one point when I started working on the "better answer" straight after a "good answer", the interviewer asked me why. I confessed that it looked to be a similar class of problem to one in the previous interview, and he told me that was excellent.

There were two problems I did badly at. One was a math question (number theory), which I got after a bit of work. The other didn't really get anywhere with. It wasn't included in any of these linked items, either, so I guess I can't say much more about it. It was a fair question though.

[ajg1977]

Can I ask what interview stage you were asked these in, and what level the position was for?

While these are good questions, in my experience they're so widely known from books/websites that I'd be amazed if a company like Google was using them for anything other than early screening of candidates.

[nl]

I did the phone screen, plus on-site interviews. It was for a developer position - I've got 10 years experience.

I was going for an overseas position, which complicated the process, because they had to fly me to another city for a combination of onsite and video interviews.

Obviously they asked other questions, too.

My impression was that they hadn't planned on doing another round of interviews, but the mixed feed back I got confused them (I did very well on at least on question, but totally bombed on another). Who knows, though - the whole interviewing process was a bit of a mess to be honest.