I had to scroll down a bazillion solutions to find someone else who bothered to solve in O(log n) time, o(1) space. Good job!

I wonder whether sorting the set and using bisect.bisect_left to find the endpoints of the numbers in [a,b) would pay off? It was only a 7 kyu problem, so I skipped that part.

I solved in Ruby, which is where the broken test case is, but the "guessed degrees" part applies to all languages.

The Python translation is getting warnings, too:

/workspace/default/preloaded.py:34: FutureWarning: Possible nested set at position 1
parse(re.finditer(f'[[\]]|[^[\]]+',solution))

Looks like f-strings aren't needed here, and re.finditer(r'\\|[^\\]+'), solution) will do what the above code seems to be trying to do.

Nice...that was quick!!

The JS translation is getting a ton of "assertSimilar is deprecated, use assert.deepEqual" warnings on stderr. It's not critical, but should be fixed to avoid confusing beginners.