@Leo heh, nice, I thought about turning that into a challenge as well :)

a simple modification of your ordinal formatter to handle odd length inputs: tio.run/nexus/…

actually, I just realised the challenge is simpler because we don't need the surrounding mirrors, so this should work: tio.run/nexus/alice#@6@fr1cX6W@taB1pXxekz@XgGaVnXxeVW6doXxUZ8/@/…

Yeah, that was about what I had in mind, but you have a useless swap in there tio.run/nexus/alice#@6@fr1cX6Z@rqBhZVRcTw@XgGaVnbx1lXWdvHxT5/…

hm, I thought I needed that for something. maybe I was trying something else, can't remember.

tio.run/nexus/… for codegolf.stackexchange.com/q/122215/8478?

the control flow can probably be improved

Wow, that looks complex

the second line is a subroutine that computes a Fibonacci number

the first line calls it once, then gets the divisors and then calls it once again for each divisor (treating the stack like a queue by processing the individual divisors from the bottom up, so that we can defer computing the sum to the end)

the return stack shenanigans are quite fun though, because the code continues after the subroutine once the loop on the first line is depleted

ok, I got your tricks with return stack, nice :)

fun fact: the outer loop over the divisors runs once more than it needs to, but it doesn't matter because F(1) = 1

nope, I didn't get this

why are you doing B1?

the B is the divisors, the 1 is just because I have the ; which discards the other Fibonacci result at the beginning of the loop

the 1 could literally be anything that pushes a single value

(and the reason I have the ; at the beginning of the loop is that I can save on a k this way... remember the nested loop trick we talked about a few days ago, which requires nested loops to be at the end of the surrounding loop?)

I remember the trick, but this is definitely more advanced :D I don't have enough time right now, I'll look at it again later to understand it better^^

@MartinEnder unrelated, but is this a bug?

hmmm, interesting

even more interesting: tio.run/nexus/alice#@6@eYOOQDwTq//8DAA

oh yeah, I know why that happens

should be fixed (on github)

and now also on TIO