[andrewcooke]

The second one isn't that hard once you recognise the kind of problem it is; then it's just a case of writing out a standard solution (I don't want to be more explicit in case I spoil it for someone else).

I have done a few of these puzzles; the ones I remember were for Quora and STA. Of those, this had least code and was quickest to write - it was fun to think about, but I didn't really learn much doing it.

In comparison, the Quora question involved various optimisations in C code (for speed) which was a bit of a time-waster - I think this tests a wider range of knowledge much more quickly. But my favourite was an STA question on inferring relatives from DNA which meant learning something new (high dimensional data; particularly locality sensitive hashing).

Personally I would prefer to see all the questions at the start, so I can see how interesting everything is, and how much time is involved. I don't really understand the advantage (to the people asking) of having them chained.

PS I find the spammy comments on this thread very odd. Are Hyperpublic themselves using sock puppets? That really makes you look bad.

[thedob]

Thanks for the feedback, and I agree that if we ever create more problems it'd be a good idea to help people learn along the way.

Re the spammy comments, our entire team are longtime HN users so we all know those hurt way more than they help, but think one of our "fans" wanted to "help" a little too much. Love their enthusiasm though.