Heh…I once was in a state-level coding event (it was a small portion of a larger competition) where half of the test was turning in code on a CD during the competition, with the written half during the event. My CD was deemed unusable for whatever reason (it had worked on XP and Fedora 6 or 7 at home) and didn't count towards my score. I still got second in the event. I declined to continue because I couldn't trust that the judges would be able judge my submission fairly and that with half of my score missing I still got second that I didn't need to prove anything else at the cost of more after-school practice hours and wrecking my perfect attendance record during my senior year to travel to nationals.
I dropped out of college (the UK version, I guess equivalent to senior high school in the US) shortly after discovering that the final assessment of my Computing project would be performed by the examiner reading a printed version of the source code, without ever executing it, because the exam board were so scared of examiners computers being destroyed.
Does high school attendance matter for anything? Genuine question. Always seemed like pre-college schooling always wanted you to think everything was more important long-term than it really was.
Perfect attendance is not a good goal to aspire to. Kids force themselves (or get forced by parents) to go to school while sick, which is probably bad for their health and also risks everybody else's health.