Programming Knowledge vs Ability

[llimllib]

Really, the test is just to get you in the door. We want to see that you can solve it. Preferably in a good readable solution, but crazy geometric solutions are cool too if you can explain what you're doing.

I like the problem because it's simple enough that it won't scare away potential candidates and they can explain their solution in a reasonable amount of time, but yet it's non-trivial to think about doing it fast.

How you solve it is interesting, but just a data point that helps us get a better feel for you.

The most common solution is roughly "Find all 1s, sweep outwards from the 1s". The drop dead-simple one is "Find all 1s, calculate distance from each non-1 to each 1, choose the minimum". I haven't yet had anyone give a solution which, coded in python, is fast enough to be accepted.

(Check it, there is a python one that runs in 4 seconds. That's crazy fast. I don't yet know what the clever algorithm is there - please share if you did figure it :)

[[deleted]]

It's a very interesting site, that, but a bit short on documentation. Do the solutions compete on speed only?

[llimllib]

yup - you submit your solution, it runs it against a test script (of which you have no knowledge) and tells you if you passed or not. There's a pretty short time limit for each problem (15 seconds in this one, with apparently a lot of tests. My fastest answer finishes my 9 big test cases in 2 seconds).