[HN Gopher] Unscrambling the hidden secrets of superpermutations
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Unscrambling the hidden secrets of superpermutations
Author : RafelMri
Score : 38 points
Date : 2024-02-10 10:39 UTC (1 days ago)
(HTM) web link (www.quantamagazine.org)
(TXT) w3m dump (www.quantamagazine.org)
| saagarjha wrote:
| [?]F "Haruhi" yields no results. Disappointed that they didn't
| even name the show!
| plagiarist wrote:
| It's frustrating the article just ends right there. "Then in
| 2014 someone did even better. The End." What was the new
| technique?
| defrost wrote:
| Eight months ago on HN:
|
| _Mystery math whiz and novelist advance permutation problem_
| (quantamagazine.org)
|
| https://www.quantamagazine.org/sci-fi-writer-greg-egan-and-a...
|
| 218 points by sashank_1509 8 months ago | hide | past | favorite
| | 97 comments
|
| https://news.ycombinator.com/item?id=36191831
|
| This new Quanta article:
|
| https://www.quantamagazine.org/unscrambling-the-hidden-secre...
| dragontamer wrote:
| Combinatorics are fun.
|
| People who like reading this article would absolutely like
| Knuth's 4A volume of The Art of Computer Programming.
|
| Which discusses Permutations, Combinations, Partitions, boolean
| tricks and more.
|
| I'm think every so often someone asks if TAOCP is worth reading.
| Well, yes. It's like this article but denser and more
| mathematical.
|
| ------
|
| I dont think TAOCP covers this superpermutaion problem. Maybe as
| an exercise though? I've only read the main section, not really
| dived into the exercise problems yet... Which are substantial and
| cover more obscure subjects.
| _a_a_a_ wrote:
| A very quick skim of the article immediately brought these to
| mind: https://en.wikipedia.org/wiki/De_Bruijn_sequence
|
| (Edit: I don't know if it's true but I've heard a story that
| these sequences were actually used by car thieves to cycle
| through all N-digit combinations with maximal efficiency. Who
| says maths isn't useful)
|
| Now, are there any combinatorists here who would be willing to
| have a private chat with me about something I stumbled upon a few
| years ago? Almost certainly well known, but I can't find any
| prior art and I've looked hard.
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