> The contest was initially inspired by Daniel Horn’s Obfuscated V contest in the fall of 2004 (note: the original page is long gone, and this link goes to a snapshot from archive.org). The object of that contest was to write a simple program to count votes, that somehow miscounts the votes on election day. I was greatly impressed to see how even a short program to simply count characters in a text file can be made to fail, and fail only on one specific day, so that the bug isn't noticed in testing.
Interesting that the case they were using was the Nuclear Threat Initiative and FP uncertainties, I've audited some, ah, nuclear-physics-related code that had an issue due to FP uncertainties...
https://underhanded-c.org/_page_id_7.html
I looked through a few trying not to read the short description and missed a lot of simple things, really makes you think...
https://graphics.stanford.edu/~danielh/vote/vote.html