It was notified that the challenge problem solutions will be rejudged after the contest.
However after rejudging, it shows a score of 0.037 against my name in the rank list, while on my submission page, it shows 0.642. When I resubmitted my solution in practice section, I received a score of 0.144.
The solutions which are pretty straight forward in their approach (print all black cells in this question) have received a higher score than me. I suppose my solution never gives an answer which is is greater than the brute solution’s answer. This is my solution:
Any insights would be really helpful.