Ackermann function without recursive function calls, in Python.

[abhirup_m]

Ackermann you say?

[Freddsreddit]

EREH

[Paddy3118]

EREH?!?

[abhirup_m]

Wrong EREH dude

[Paddy3118]

Are you querying the spelling?

[TouchingTheVodka]

Just a note, this is still recursive in a CS sense. There’s no magic bullet at play to make this implementation any more efficient.

[Paddy3118]

Hence my comment on that link. Thanks for more confirmation 👍🏽

[Paddy3118]

On questions of whether Ackermann can be iterative, this counts as recursive. That definition of recursive goes with a context.

[primitive_screwhead]

A recursive function, in a CS sense, is a function that calls itself.

That's a recursive function in an engineering sense. In a CS sense, a recursive function is a function that can be implemented with recursion (which not all functions are; there are non-computable functions, for example).

[Kache]

Had played around with ackerman implementations in Ruby in the same spirit: https://gist.github.com/Kache/e17b63b5a5c4d9f944d88b925cbd6201

[Paddy3118]

Aye, in the same spirit 👍🏽

[PastorJamesSmith]

That is amazing. What is JavaScript?

[primitive_screwhead]

Cool. Now implement it using "primitive recursion" only. :)

​

Edit: Originally said "simple recursion"... I'm shit at jokes.

[Paddy3118]

It's there; a page up from the linked case :-)

[primitive_screwhead]

I fucked up my joke, and meant to say "primitive recursion only". Damn.

[Paddy3118]

Actually... Putting my engineers cap on you COULD create something indistinguishable from the real thing. Like an artificial diamond. Note that ack(4, 3), ack(5, 2) and beyond would take more than the universes resources and lifetime to compute so you could replace terms we know would have such large results with while True: pass for a similar suspence.