By and large. Major League Hacking (the link above) is sort of like the national group "in charge" of hackathons and one of the requirements to be recognized by them is to be a purely under-grad event (though sometimes highschool students are admitted). That said, there are plenty hackathons that aren't sanctioned by MLH and therefore are more open.
It's also possible that my view of hackathons is skewed by the fact that I'm a university student at a school with a very active hackathon culture.
- Stable: Equal keys aren't reordered.
- Operates in place, requiring O(1) extra space.
- Worst-case O(n·lg(n)) key comparisons.
- Worst-case O(n) swaps.
- Adaptive: Speeds up to O(n) when data is nearly sorted or when there are few unique keys.
There is no algorithm that has all of these properties, and so the choice of sorting algorithm depends on the application."
Is there any formal proof that such an algorithm doesn't exist? Are some of those criterion mutually exclusive?