> It needed to run in less than 1 second I've always wondered how these competitions measure the program's runtime consistently. I guess the easiest way would

> It needed to run in less than 1 second I've always wondered how these competitions measure the program's runtime consistently. I guess the easiest way would be to specify the CPU the program will run on and use the bash `time` builtin, but that seems inconvenient for participants to obtain that CPU and controlling for the cache might be difficult (maybe a kernel module that clears the cache before the program runs and make sure the program runs fully in cores dedicated to that program and is consistent enough with memory accesses so L3 is comparable). On the other hand they could just count instructions run, which would be completely deterministic, but might lead to some "optimizations" that don't make sense like using `rep movs` to zero memory instead of loops. Using a higher-level bytecode would have the same problems. They could also give different values to each instruction and possibly memory access, but even then students would be ignoring important real-world cache or pipeline optimizations. But maybe I'm just overthinking this. This type of problem would be better suited for GPUs anyway.