Could be easily made 50% space saving by only iffin all odds and return even on else. Maybe one if before to handle overflow to avoid wrong even if over the last if.

[–] Deebster@programming.dev 41 points 9 months ago

Well yeah, if you allow cheating!

[–] bjorney@lemmy.ca 18 points 9 months ago* (last edited 9 months ago) (1 children)

Yeah but then ALL even numbers would be slow to compute because you would have to chain through every odd before you know that 2 is even.

Depends on the expected distribution of input values

[–] coloredgrayscale@programming.dev 1 points 9 months ago

Heuristic: keep it until 512, afterwards powers of 2, and numbers like 1000, 2000,.., 10000, 20000,... (regex: [0-9]000+)