I posted this as a comment on the last contest, but upon request, I turned it into a blog post so that it may get more attention.
Is there any way to hack consistently with regard to a segfault? There were a few times that I've seen people accessing, say, s[n] when s only had n elements allocated to it, which should cause a segfault, but because of the magic of operating systems, segfaults only happen sometimes. These people will probably fail during systests, but I can't reliably hack because even if I submit a hack, the OS might not complain about a segfault and I'll get an unsuccessful hack. Is there any way around this or should I just not try to induce a segfault in a hack?