The eighth post of the series of programming job interview challenge is out. 68 readers provided answers to job interview challenge #7 and most of them had the correct solution. As rvh mentioned, the trick here was to understand that the round table has a symmetric shape and: Actually this algorithm isn’t limited to just a round table. It will work with any shape that is symmetric with respect to both x and y axes. I couldn’t describe the correct answer better than Yoav Zobel, as he was the first one who also formally proved his algorithm:

The Correct answer (as provided by Yoav Zobel):