• superkret@feddit.org
    link
    fedilink
    arrow-up
    8
    ·
    2 months ago

    What if the remainder is greater than the first, but not less than the latter?

    Like, for example, 1?

    • prime_number_314159@lemmy.world
      link
      fedilink
      arrow-up
      3
      ·
      2 months ago

      Then you should return false, unless the remainder is also greater than or equal to the twenty second root of 4194304. Note, that I’ve only checked up to 4194304 to make sure this works, so if you need bigger numbers, you’ll have to validate on your own.

      • fartripper
        link
        fedilink
        arrow-up
        5
        ·
        2 months ago

        i hate to bring this up, but we also need a separate function for negative numbers

        • prime_number_314159@lemmy.world
          link
          fedilink
          arrow-up
          1
          ·
          2 months ago

          You can just bitwise AND those with …000000001 (for however many bits are in your number). If the result is 0, then the number is even, and if it’s 1, then the number is odd. This works for negative numbers because it discards the negative signing bit.