Let us substitute: ( - x, ) - y
Thus ()() becomes xyxy
())( becomes xyyx
Now clearly it can be seen, even while high, that the second one is and the first isn’t
for those too lazy to google,
palindrome /păl′ĭn-drōm″/
noun
A word, verse, or sentence, that is the same when read backward or forward.
"madam; Hannah; or Lewd did I live, & evil I did dwel."
Calm down, everyone. Brackets form a tree structure, and can be represented by a free magma, while strings with concatenation are equivalent to a free monoid. You're essentially asking for the two respective common involutory operations to be connected by this map, just because they're involutory, which put that way is a wild guess at best. In fact, reversing this string produces something outside the range of the map entirely, which is injective and so can't be surjective for combinatorical reasons.
... Yeah I might be the only person that finds that useful.
::: spoiler I mean,
the part about the "wild" guess is, but this is a counterexample, and something like the reciprocal vs the negative of reals or rationals when moved across the log map would be an example. So, either you're a galaxybrain that just instantly knows if the transformation is structure-preserving in that way, or you're guessing to some degree as well.
:::
The symbols and abstractions have touched me in no-no ways. I miss okaybuddyphd on r*ddit, they knew the pain.
I suppose I could also just say that characters which aren't just drawn asymmetrical, but actually point in a direction as part of their function, look wrong when reversed like this. So, (e) -> )e( is no good, but bed -> deb is fine.
I was saying unipotent at first instead of involutory, which was actually the wrong jargon because of the context, but I've fixed that now. Yes, they're all real.
Map, although in this context I could probably have just said function. I go with map by default when thinking bidirectionally.
I think most people here will know combinatorics, the study of the different possible configurations of something. The number of n-length strings with two possible characters is 2^n^, as coders should all know, and the number of trees turns out to be Catalan numbers, many of which have prime factors other than 2. This is an injective map from n node trees to 2n character strings, so it's possible, but you'll (almost?) never get a perfect match, so by the pigeonhole principle it can't be surjective.
I'm wondering now if Catalan numbers are O(n!). The equation has a lot of n! but it also has a certain smell like it might depend on big or little o.
Edit: D'oh, they must grow no faster than 2^2n^; I just wrote that. So, exponential.
Yes it does bother me a little that the letters in the latter half of my username can't be written backwards. (Well, some can, and the p can become a q, but then it's not a p any more.)
That's a palindrome because the reverse is the same. The comment above you shows that the one above isn't a palindrome since the reverse is different, not showing a palindrome
It's not complicated at all: https://en.m.wikipedia.org/wiki/Palindrome. Not really something that's education-specific, in this instance (though I suppose it's commonly used in entry-level programming classes since it's a simple concept).
Yea but I'm just generally dumb in a pool of smart people. Not like I'm using palindromes in everyday conversation so when I see it I gotta look it up. Like when I saw a Fibonacci sequence and mentioned that it looks like something I've seen before but couldn't remember where. This doesn't even touch on why the syntax mentioned is a palindrome 😆
They are only useful as nerd jokes, interesting math facts (with no real world application), and stupid leetcode algorithms (with no real world application).
Nearly everybody here knows about them because nearly everybody here is exposed to lots of instances of those 3 categories. You could be feeling out of the loop, but you shouldn't at all get impostor syndrome from it.
That's actually a great response and just wanted to let you know I appreciate it. I'm actually pretty good with where I'm at and just joking around but your messages made me feel good and I wanted to let you know that and I appreciated it
All it means is if you were to reverse the order of the characters, you'd get the same string you started with. So "dog" isn't a palindrome because when you reverse it, you get "god". "dog god" is a palindrome, though, because if you read it backwards, it's also "dog god".
This is especially terrible when lying in bed. With a keyboard or pen and paper you can make sense of it, it hurts my brain a bit to visualize it though.
It's curious, but in my mind these types of mathematical or logical visualizations are the sheep I count, trying to sense the deeper flow and patterns where the emergent oddities even out.
That's when I know I will soon fall fast asleep, when my mind starts getting abstract.
It looks very weird, but if you put it like abab vs abba, it makes more sense
bdbd is not a palindrome but bddb is
I hate it
bddb is my favorite word to pronounce
I think you just hacked my modem
Is it pronounced like that Super Troopers Porsche song?
Maijin bddb
Yes, baddragonbaddragon is, in fact, not a palindrome.
Username checks out.
:3
This is much easier to parse for me than the one in the post. Interesting. I guess letters are easier to abstract
I hate this even more than the original one. At least the original one had a horizontal line of symmetry to calm me a bit.
mamma mia
Here I go again
"()()" is an ambigram, which wikipedia describes as "visual palindromes", for whatever that's worth.
WIKIPEDIA CAN SHOW GIFS?!
Oh boy, they have some good ones. You've been missing out.
Edit: Quicksort has a nice one. SVD for linear/matrix operations too.
I'm pretty sure I've seen even better ones that could almost stand as a YouTube video but I can't remember where now
I love that the word ambigram can be made to look as an ambigram whereas palindrome - wtf, could have done so much better with naming that guys.
hippopotomonstrosesquipedaliophobia (Fear of long words) was clearly not defined by anyone suffering from the phobia either.
Well that's just mean.
This is an unacceptable glitch in the universe.
It's time to reboot it with a patch.
Let us substitute: ( - x, ) - y
Thus ()() becomes xyxy
())( becomes xyyx
Now clearly it can be seen, even while high, that the second one is and the first isn’t
for those too lazy to google,
palindrome /păl′ĭn-drōm″/ noun A word, verse, or sentence, that is the same when read backward or forward. "madam; Hannah; or Lewd did I live, & evil I did dwel."
() () backwards is )( )(
() )( backwards is () )(
This has ruined my day.
this took me a while but after converting to ascii in hex I get it
"())(" = 40 41 41 40
"()()" = 40 41 40 41
As long your strings aren't null terminated
What kind of monstrous bug prone language would do that?
What about ⊂((・▽・))⊃
⊃))・▽・((⊂
(╯°□°）╯︵ ┻━┻
┻━┻ ︵╯）°□°╯(
Why would you do this to me 😭
Oh god, please no 😄
1212 isn't a palindrome, but 1221 is.
That's horrible and horrifying and I'm never gonna sleep again and also I hate you :(
Had to take a break and come back later before it made sense.
Calm down, everyone. Brackets form a tree structure, and can be represented by a free magma, while strings with concatenation are equivalent to a free monoid. You're essentially asking for the two respective common involutory operations to be connected by this map, just because they're involutory, which put that way is a wild guess at best. In fact, reversing this string produces something outside the range of the map entirely, which is injective and so can't be surjective for combinatorical reasons.
... Yeah I might be the only person that finds that useful.
yeah but that's just like your opinion man
::: spoiler I mean, the part about the "wild" guess is, but this is a counterexample, and something like the reciprocal vs the negative of reals or rationals when moved across the log map would be an example. So, either you're a galaxybrain that just instantly knows if the transformation is structure-preserving in that way, or you're guessing to some degree as well. :::
The symbols and abstractions have touched me in no-no ways. I miss okaybuddyphd on r*ddit, they knew the pain.
I suppose I could also just say that characters which aren't just drawn asymmetrical, but actually point in a direction as part of their function, look wrong when reversed like this. So, (e) -> )e( is no good, but bed -> deb is fine.
I'm just going to assume those 4 dollar words are real and you aren't just misspelling normal words to fuck with us.
Non surjective free magma? What about the doblastic amortized basalt?
I was saying unipotent at first instead of involutory, which was actually the wrong jargon because of the context, but I've fixed that now. Yes, they're all real.
A glossary:
Involution
Surjective
Injective
Free magma
Free monoid
Map, although in this context I could probably have just said function. I go with map by default when thinking bidirectionally.
I think most people here will know combinatorics, the study of the different possible configurations of something. The number of n-length strings with two possible characters is 2^n^, as coders should all know, and the number of trees turns out to be Catalan numbers, many of which have prime factors other than 2. This is an injective map from n node trees to 2n character strings, so it's possible, but you'll (almost?) never get a perfect match, so by the pigeonhole principle it can't be surjective.
I'm wondering now if Catalan numbers are O(n!). The equation has a lot of n! but it also has a certain smell like it might depend on big or little o.
Edit: D'oh, they must grow no faster than 2^2n^; I just wrote that. So, exponential.
You are awesome.
Lemmy is better for you being here. Thanks for the reading material!
You're very welcome! How kind.
I'm not saying I was having a good day before, but this made it that lil bit worse.
Thank you for letting me hate it as well.
Yes it does bother me a little that the letters in the latter half of my username can't be written backwards. (Well, some can, and the p can become a q, but then it's not a p any more.)
Best palindrome I ever come across is boob. I heard Jimmy Carr say it, but he could be repeating somebody else's joke.
dood
Wild stuff.
fuck that was unexpected
What about ))-((
The reverse would be ((-))
Wouldn't it be ()-)( as a palindrome?
That's a palindrome because the reverse is the same. The comment above you shows that the one above isn't a palindrome since the reverse is different, not showing a palindrome
Yeah I realized
A palindrome is about symbols. Not the visual representation of those symbols.
Palindromes? Haha right guys so funny
Totally not feeling inadequate as a vs graduate again. How bout them FAANGS, haha Arch
It's not complicated at all: https://en.m.wikipedia.org/wiki/Palindrome. Not really something that's education-specific, in this instance (though I suppose it's commonly used in entry-level programming classes since it's a simple concept).
Yea but I'm just generally dumb in a pool of smart people. Not like I'm using palindromes in everyday conversation so when I see it I gotta look it up. Like when I saw a Fibonacci sequence and mentioned that it looks like something I've seen before but couldn't remember where. This doesn't even touch on why the syntax mentioned is a palindrome 😆
Nobody uses palindromes in everyday conversation.
They are only useful as nerd jokes, interesting math facts (with no real world application), and stupid leetcode algorithms (with no real world application).
Nearly everybody here knows about them because nearly everybody here is exposed to lots of instances of those 3 categories. You could be feeling out of the loop, but you shouldn't at all get impostor syndrome from it.
That's actually a great response and just wanted to let you know I appreciate it. I'm actually pretty good with where I'm at and just joking around but your messages made me feel good and I wanted to let you know that and I appreciated it
All it means is if you were to reverse the order of the characters, you'd get the same string you started with. So "dog" isn't a palindrome because when you reverse it, you get "god". "dog god" is a palindrome, though, because if you read it backwards, it's also "dog god".
Do you even nerd bro? I bet you have sex too.
Only Arch in my day is the one in my girlfriend's back as I crank my hog to old Superbowls on VHS bro
This is especially terrible when lying in bed. With a keyboard or pen and paper you can make sense of it, it hurts my brain a bit to visualize it though.
By the gods
Tbh, at first sight I was like "wtf they're talking about? Is this a regexp or some kind of string formatting? In which language?"
Ahaha I hate you. Have a great day !
Fucking.
It's curious, but in my mind these types of mathematical or logical visualizations are the sheep I count, trying to sense the deeper flow and patterns where the emergent oddities even out.
That's when I know I will soon fall fast asleep, when my mind starts getting abstract.
open close open close
open close close open
I don't know what a palindrome is, it looks like iam better off this way.
A word, number or string that can be read the same backwards and forwards. Like 2112, 11/11/11, "A Toyotas a Toyota", "Was it a cat I saw?".
I can't be the only one who has no issue seeing this right? It's very obvious which is a palindrome and which isn't.
🥇
I'd like to thank the academy of palindrome sciences
I was like you earlier. It will hit you.