Missing the instruction panel where the customer is attempting to follow the baffling instructions and has to use a wired phone to call the store for help.

Getting quicksort's boundary conditions right (avoiding off-by-one errors, infinite recursion, etc.) can be tricky.

Another popular algorithm that can be hard to get right is binary search.

BINÄRY SEARCH has you covered. (-:

* https://idea-instructions.com/binary-search/

The second page is borderline incomprehensible, I'm not sure I would ever understand what it's trying to say if I didn't already know.

Stuck in second round of step 2, since there is no middle cup to lift!

I kind of get it, but just like Ikea instructions, you start second guessing yourself, then you realize, its BACKWARDS after you flip back 5 pages in when something doesn't fit.

Reminds me of when I was assembling some drawers and put in the bottom of one upside-down. At least I wasn't the one using them...

Are you on about the ones where the bottom is carboard that could go either way? LOL I hate building those.

Ikea instructions are like an Easy to Medium level test in reverse engineering skills, with occasional EXPERT TIER SUPREME level skills needed because of subtleties.

at best I can see trouble in interpreting "throw cube and shade a bar" as "choose randomly"

but if you don't understand it at all... I have bad news for you

I can understand it after some deciphering, but I think that’s only because I already know quicksort. I’d be interested in seeing if anyone new to sorting algorithms finds it illuminating.

Then again, maybe that’s not important to the author - it is a pretty funny illustration to those in the know.

I'm a programmer (after a fashion) but I don't know how quicksort works.

This is how I understand it after reading these instructiöns, without looking up any further explanation:

1. Choose a random element as the 'center' point of the sort

2. That element defines the maximum 'height' (value)

3. Anything that is larger than that value, is moved to the right side of the 'center'

4. Anything that is smaller than that value, is moved to the left side of the center. After this, the array is partially sorted.

5. The sorting process is repeated on both 'sides' independently, picking a new random center element and so on

What isn't clear, is how often the process needs to be repeated, or when the algorithm 'knows' that the sorting has been finished - surely it can't be just three iterations?

By now I've already looked up how the algorithm actually works, but the above is what I got out of the illustration :)

Yeah, that's about it. Personally, I'm not sure I'd get this much out of the picture, but you can see the information is there.

> surely it can't be just three iterations?

To save others a search: you stop when the remaining sub-arrays are sorted by definition (ie. [] or [x]/size of 0 or 1).

Also, to save any further puzzling: In practice the very fast sort you use, even if it is labelled "Quicksort" probably doesn't actually do this "all the way down" even though that's the strict algorithm.

They'll have a highly optimised small sort and use that whenever sorting very small things. So e.g. IPN Sort the Rust stdlib unstable sort will do this for 16 items, even though for a big slice it'd quick sort them by default, once it's down to say 10 items they're going to the specialised small sort.

Any serious "fast" sort in 2025 will be a hybrid, using several of these classic sorting algortihms, plus other insights to produce the overall best solution to their problem on modern hardware.

Would be better if the die had lettered sides that matched up to the bar positions. With "3" it's hard to be certain it's the bar position and not the height.