The Nineteenth Byte

New Main Posts

22:05

-5

Jack is a little businessman. He found out a way to earn money by buying electricity on days when it's cheap and selling it when it's much more expensive. He stores the electricity in a battery he made by himself. You are given N, the number of days Jack knows the cost of electricity for, and X, ...

Zacharý

22:45

Holy downvotes

Anybody know what this static results from?

flawr

@DJMcMayhem you can also "overlook" and "overlook"

Zacharý

Anonymous

@Zacharý I'd guess a bad VGA connection/cable

caird coinheringaahing

Regex Q: If I have a repeated string and want to capture each of the repetitions, how would I go about that? E.g. "abc def ghi" => ["abc", "def", "ghi"]? (<match>)* doesn't seem to work :/

DJMcMayhem

@cairdcoinheringaahing What flavor?

Dennis

22:52

That's not really a regex question. What programming language are you using?

caird coinheringaahing

Python

DJMcMayhem

^^

Anonymous

s.split()?

caird coinheringaahing

No, the strings themselves are more complicated than that (hence regex)

DJMcMayhem

So re.findall("\a+", s), or even better what Mego said

Dennis

22:54

Well, split works only for whitespace or a fixed string.

@DJMcMayhem What's \a?

DJMcMayhem

In vim it's [a-zA-Z], but I don't really know other flavors, so maybe that isn't standard

Dennis

Python doesn't have it. tio.run/##K6gsycjPM/7/…

DJMcMayhem

Vim is the only regex I'm familiar with, and it has some quirks (for example, '+()?' all need to be escaped)

Pavel

@Dennis It's the regular string escape for the bell character

I think Dj meant \\A

DJMcMayhem

@Pavel That throws a ton of errors for some reason o_O

Dennis

22:56

@Pavel Fair point. r'\a' doesn't work either though.

Pavel

Which is start of line

@Dennis Right. Capital A.

DJMcMayhem

I think python regex just doesn't have that

Dennis

No, that doesn't work either.

Python's re doesn't use PCRE.

Anonymous

\A is start of string

Anonymous

Python doesn't have a shorthand for [a-zA-Z]

Pavel

22:57

Oh, I didn't know that's what you were trying to do

DJMcMayhem

@Dennis sigh. I just shouldn't ever be asked regex questions that aren't in vim

New Main Posts

-1

Q: John's lost arrays

John has made an array or a few containing numbers which are important to him. Unfortunately, John lost the arrays. Luckily, he knows some details about the arrays. You are given T, the number of test cases, and in each test case you are given N, the number of digits in the array, and M, the numb...

array-manipulation

Anonymous

The fact that \A and \Z are start and end of string (respectively) makes me happy

DJMcMayhem

What the heck? What's wrong with ^ and $?

Downgoat

.____.

Pavel

22:59

@DJMcMayhem ^$ are start and end of line.

\A and \Z are for multiline strings

Anonymous

@Pavel Exactly. \A and \Z aren't affected by the multiline setting

Dennis

@Downgoat Heh, that reminds me about the falsehoods programmers believe about time.

DJMcMayhem

How would you abbreviate micrograms if you can't type the weird 'u' symbol thing ('mu')? Using only ASCII

Would that just mcg?

Anonymous

@DJMcMayhem I'd probably do mmg, since m is 1/1000

DJMcMayhem

So... milli-milli-grams?

Dennis

23:06

mcg is the most common ASCII alternative.

Although, in the interest of clarity, I wouldn't abbreviate it at all.

Anonymous

@DJMcMayhem Sure, it's only slightly heinous

Anonymous

CMC: given a blasphemous abbreviation of a unit (like mmg for µg or kmm for m), normalize it

DJMcMayhem

@Mego How are you getting kmm=m?

Oh wait...

Kilo-milli-meters?

Anonymous

Yes

DJMcMayhem

@Mego My response is a kilo-ಠ_ಠ

Anonymous

23:09

i.e. multiply the scaling factors of the prefixes, and then use the appropriate prefix

Anonymous

@DJMcMayhem I did say blasphemous

Dennis

Please add mmHg as a test case.

Anonymous

@Dennis I think you mean µmkHg :P

Adám

@Mego µmkHgm/m

Dennis

Um, the second m is meter.

Anonymous

23:14

mJHg/kg/s/s

Pavel

I see Hg and can't parse it as anything but Mercury

Anonymous

@Pavel It's supposed to be mercury

Dennis

Yes, mmHg is millimeters of mercury.

Pavel

Ah, I thought there was an H prefix being applied to meters.

Dennis

A rather archaic unit that is still widely used to measure blood pressure.

Anonymous

23:15

mmHg is a standard unit of pressure, used in medicine

Pavel

@Mego Bonus points: Convert crap units to sane units, e.g. kyd -> .9144km

Zacharý

kyd?

DJMcMayhem

Kilo-yard I assume

Pavel

Yep

Zacharý

@Mego I forgot to give context, it was when I was running the Allegro5 library with a D wrapper.

Pavel

23:20

W|A parses it, therefore it's a real unit: wolframalpha.com/input/?i=7+kyd+to+m

Dennis

I always forget: how many pinky toes are there in a yard?

Pavel

I can't even remember how many feet there are. I just have a vague understanding of how much a yard or a foor or an inch is, and can't do unit conversions at all.

Dennis

3 ft = 1 yd

Adám

1U → 0.1778 m

DJMcMayhem

@Dennis ... 3?

Anonymous

23:21

@Dennis More than 1

Zacharý

@DJMcMayhem That's why USA is weird

Pavel

Also, 5280 feet in a mile. Dafuq.

DJMcMayhem

@Zacharý s/USA/imperial system

Zacharý

@Pavel I only remember that do to my friend's quiz he made a while ago.

Pavel

@DJMcMayhem Over 99% of people who use the imperial system are 'murican.

Zacharý

23:22

@DJMcMayhem It's technically a modified imperial system.

Dennis

Theoatmeal has a nice article on imperial units, but it's probably a bad idea to link it here.

Pavel

@Dennis Is it?

Adám

nLD → 0.380 m

Pavel

@Adám What's a U or a nLD?

Zacharý

@Adám WTF are you listing?

Dennis

23:23

@Pavel Generally NSFW.

DJMcMayhem

@Zacharý Oh? How so?

Adám

@Zacharý Unusual units which have an abbreviation.

Pavel

@Dennis Surely the one on units isn't.

Dennis

Looks like it isn't. theoatmeal.com/comics/senior_year

Adám

U is for rack Unit, LD is Lunar Distance.

Zacharý

23:25

@DJMcMayhem By fitting them exactly to metric (albeit with conversion factors aplenty), IIRC

Pavel

@Dennis Ok, "Five medium-sized gerbil penises" is a little NSFW.

DJMcMayhem

@Dennis It's not NSFW per se, but it does include Gerbil Genitals in the first panel :P

Pavel

ninja'd

Adám

1 mDDB → 0.1125 m³

DJMcMayhem

FWIW, I fully agree that imperial is dumb, and I would rather use metric. But since I don't use metric, and I've learned to think in imperial, there's no way I would switch.

Pavel

23:28

I'm fine with both, except I never did figure out Fahrenheit.

I grew up in a metric-system-using household.

Dennis

"Radians Fahrenheit or radians Celsius?" "Uh, sorry, gotta go!"

3

Zacharý

@DJMcMayhem That's the entire reason imperial/US units even exist any more

Pavel

@Adám I'm pretty sure that last one isn't a real unit

DJMcMayhem

@Zacharý Well, that and the staggeringly enormous cost it would take to change all existing infrastructure over to metric

Can you imagine how much it would cost to change every single road sign, not to mention the million other things that would have to change?

Adám

@Pavel It is.

Pavel

23:31

> Assuming new Routemaster double decker buses for "DDB" | Use old Routemaster double decker buses instead

Well shit

Zacharý

@DJMcMayhem I think there's a town in US that uses metric, due to this fact (as it was created right after an act allowed metric, or something)

Adám

@Pavel I guess my value applies to a different model.

Zacharý

23:44

Still, why would we need abbreviations for this stuff?

Zacharý

23:58

Like, really? Double decker buses?

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