Think about this. You need to calculate the number of permutation for 4 digit codes. Then you need to arrange them in every order possible to brute force. So that’s 4!!. That’s a lot: roughly 620000000000000000000000 combos.
That's the number of possible codes. Not the number of possible ways you could arrange all 10000 codes to see which ordering contains the most shortcuts.
i have a python script running through that right now to find "the shortest" and it's been burning a single core for at least 6 hours. So it looks like you are right and i am wrong ;-)
i assume my pc on a single core can do ~1billion permutations per second, this will take 19,647 millennia. AFK.
what do you think the chances are, if i let this run, that it would find a shorter solution than 625 keypresses? the naive De Bruijn algorithm popped that out in like 2 seconds.