Why isn't it possible to run these contexts in a computer room with no access to the Internet? This plus a minimal amount of supervision would remove cheating?
Am I missing something?
Maybe schools don't have a computer room these days?
The first stage (this one, with ballpark 10000 competitors) is distributed and done in very heterogeneous environments, and it relies on local high school teachers taking time out of their day to set up whatever's needed, proctor the contest, and grade the results.
"could have", yes, but mostly didn't until LLMs showed up.
The problem is that LLMs lower the bar to cheating: using Stack Overflow still requires a pretty solid knowledge of the domain (and in a professional coding context, usually wouldn't even count as cheating). The LLMs also let you do this much faster.
I don’t know if I would consider this modern coding using modern coding tool chains anymore though. It might still be a nice competition to run, but it is increasingly displaced from what it means to be a professional programmer (I’ve stopped caring about these competition wins on resumes a long time ago).
Some of the best engineers (I mean that in the broad sense, not just “were good at coding up algorithms”) I had the privilege of working alongside with scored highly on these competitions.
Outside of being highly ironic, this is how you get a GAN arms race :)