The Nineteenth Byte

Bigtoes

19:00

If you get the digit sum without stringifying it, you get 80 bytes:

int a(char[]a){int s=1,t;for(int b:a){for(t=0;b>0;b/=10)t+=b%10;s*=t;}return s;}

But you lose the smiley :/

Poke

just change one of the other vars

Bigtoes

Yea, b to c would work

Poke

i was about to say that assumes a 2 digit ascii code but... yeah ascii

Bigtoes

I think it only assumes a non-zero code, but either way, yea.

Poke

oh yeah my bad

Bigtoes

19:03

Let's just hope the input string doesn't have nulls o_O

Poke

and there are 3 digit ascii codes for letters anyway

so i'm a dumb

@TimmyD can the input contain null

TimmyD

@Bigtoes That's a safe assumption.

Poke

noice

TimmyD

We'll limit to printable ASCII

Poke

man if only toCharArray() wasn't a million characters

though i think yours still might be better...

TimmyD

19:06

@Bigtoes Does Java not care that the function name and the input variable name are the same?

Bigtoes

Nope

Poke

java has good type safety which is a pro for java i guess

that left shift mask that i mentioned earlier applies to java as well so java has netted 0 today

Nathan Merrill

@Poke its going to apply to nearly every language, unless they wrote their own bit shifter

Poke

Go and python don't do it iirc

Nathan Merrill

its 0xFFFFFFFF<<32, right??

Poke

19:10

ye

TimmyD

PowerShell apparently wraps

PS C:\Tools\Scripts\golfing> [int]$a=0xFFFFFFFF;$a;$a-shl31;$a-shl32;$a-shl33
-1
-2147483648
-1
-2

Nathan Merrill

func main() {

	fmt.Println(0xFFFFFFFF<<32)
}
prog.go:8: constant 281470681743360 overflows int

it tried to compiletime generate XP

Poke

haha

feersum

looks like PS allows the hardware to decide the behavior

TimmyD

In binary:

PS C:\Tools\Scripts\golfing> [int]$a=0xFFFFFFFF;[convert]::ToString($a,2);[convert]::ToString($a-shl31,2);[convert]::ToString($a-shl32,2);[convert]::ToString($a-shl33,2)
11111111111111111111111111111111
10000000000000000000000000000000
11111111111111111111111111111111
11111111111111111111111111111110

feersum

19:13

in x86 x << y is equivalent to x << (y & 31) in 32-bit ints

TimmyD

Maybe it takes modulo, lol

Nathan Merrill

hmmm

func main() {
	for i := uint32(0); i < 32; i++ {
		fmt.Println(0xFFFFFFFF<<i)
	}
}

this is still throwing an overflow error

so, it appears that its bitshift to make a bunch of zeros doesn't even work

feersum

What if you make 0xFFFFFFFF unsigned? or is it already?

Nathan Merrill

oooh, got it

func main() {
	for i := uint32(0); i < 33; i++ {
		fmt.Println(uint32(0xFFFFFFFF<<i))
	}
}

feersum

That doesn't make sense

You shifted it before making it unsigned

Nathan Merrill

19:16

nah, I was casting it so it doesn't throw an overflow error

everything is unsigned

feersum

How can Print(x) be an overflow but Print(uint32t(x)) not?

Nathan Merrill

er, not sure about 0xFFFFFFFF, but I don't think it matters

@feersum because its an explicit cast

feersum

I don't know this language; how could that matter?

Nathan Merrill

well, the bitshift is trying to produce a number outside the range of int

so, by default, it throws an error

but since I cast it to an int, I say that its ok, and to simply trim off the upper bits

Poke

"unsigned" is how it's interpreted. 0xFFFFFFFF is 32 1-bits. You can interpret it as an unsigned int (2^32 - 1) or as a signed int (-2^31) through (2^31 - 1)

well that was two different thoughts mashed together

but you get the point, i hope?

feersum

19:20

@Poke Do you know this language, or are you making stuff up?

Poke

this is how computers work

o.O

it's language independent

feersum

You're making stuff up. I see.

Poke

?

0xFFFFFFFF is a 32 bit integer

you can interpret it however you want

mbomb007

I think I found a bug with filtering on the site. If I try to exclude a tag, that tag's text is included in the search, further narrowing the scope of my search past my intended scope.
http://codegolf.stackexchange.com/search?q=-%5Bcode-golf%5D

Searching for simply `[code-golf]` returns only questions tagged with that tag, but searching for `-[code-golf]` does not return all questions NOT tagged with it, and it also returns answers containing either `code` or `golf`.

I have to specify "is:question" to get what I want.

feersum

@NathanMerrill What is the type of 0xFFFFFFFF in Go?

Nathan Merrill

19:21

no idea

TimmyD

@Poke Big endian or little endian? :p

Poke

/cringe

Nathan Merrill

@feersum looked it up, its an "Integer literal", which says to me signed, but I don't know for sure

8

Q: Searching for posts without a tag borks the search parameters

Currently, search seems to be doing odd things when you search for posts without certain tag(s) using the not operator. For example: -[css] -[html] should return a list of posts that do not have the CSS or HTML tags, and it correctly looks for that criteria. However, it also seems to change my s...

TimmyD

In PowerShell, the 0x is actually an operator that returns a signed int

mbomb007

@NathanMerrill Thanks.

TimmyD

19:25

so, something like [uint32]$a=0xFFFFFFFF would throw a cast error

feersum

I found this in Go spec:

> Except for shift operations, if one operand is an untyped constant and the other operand is not, the constant is converted to the type of the other operand.

I don't see what happens for shift operations.

But an untyped constant seems to be what you have.

TimmyD

I suppose, technically, it's throwing an ArgumentTransformationMetadataException error. Because PowerShell.

flawr

ArgumentTransformationMetadataExceptionThrowerBuilderClassFactoryTemplate

Nathan Merrill

errr, I'm pretty confused now

TimmyD

@flawr you forgot the throws ArgumentTransformationMetadataException

feersum

19:29

var i = 1<<s           // 1 has type int
var j int32 = 1<<s     // 1 has type int32; j == 0

Nathan Merrill

func main() {
	fmt.Println(0xFFFFFFFF)
}

^ that throws an error

constant 4294967295 overflows int

TimmyD

It's probably because Println is overloaded

feersum

I don't think so.

It's because the default type for untyped integer literals to covert to is int

Which is equivalent to int32 at least in this implementation

mbomb007

7

Q: Tag search NOT operator is broken

Searching for "-[feature-request] [comments]" should return a list of questions that have the tag [comments] but not the tag [feature-request]. The right hand sidebar says that, but the search results are identical to "[feature-request] [comments]". As random points out, the operator works, bu...

bug status-completed tags search

TimmyD

Ah, that makes sense

feersum

19:31

Woo 0 to language lawyer in 60 seconds

mbomb007

Searching with only a NOT operator is apparently not allowed/supported.

Nathan Merrill

huh

flawr

@TimmyD oh right=)

Nathan Merrill

good to know

mbomb007

Makes sense for other sites with millions of results.

But when 4/5 questions on PPCG is code-golf, I wanted to see the others. Fixed by using is:question

TimmyD

19:33

I wonder what sort of magical parsing causes - to break it.

Nice find, though. That's a useful tidbit.

Nathan Merrill

so, it looks like 0x...is always unsigned

and then it casts it to a signed integer

aka, fmt.Println(0x7FFFFFFF) works, but fmt.Println(0x80000000) doesn't

its also not related to the Println

var a = 0x80000000 throws an error as well

RenderSettings

Is there a collapsible spoiler tag I can use in a post?

Nathan Merrill

@Poke just tested in in python: it uses its own integer datatype, so bitmasking won't really work

@RenderSettings there isn't anything collapsible in a post, IIRC

the best you can do is a stack snippet I think

RenderSettings

Hm. :/ The finite field challenge wants me to post a multiplication table, which is long...

Poke

pastebin?

FryAmTheEggman

19:43

If it isn't totally necessary to show your answer is valid, you could link to pastebin or something

RenderSettings

"If you use a built-in function, please also describe in words which result it produces (e.g. provide a multiplication table)."

Also pastebin is evil

FryAmTheEggman

You could describe one illustrative case, then show the rest?

Nathan Merrill

@RenderSettings the other answers don't seem to be providing a table, so I'd just follow suit

RenderSettings

They aren't using a built-in

Nathan Merrill

ah, you're right

RenderSettings

19:45

Whatever, I can just show (m 0x53 0xca) == 1

Eᴀsᴛᴇʀʟʏ Iʀᴋ

halllooo

flawr

@EᴀsᴛᴇʀʟʏIʀᴋ hi mister irk

Eᴀsᴛᴇʀʟʏ Iʀᴋ

s/mi/ea/

flawr

@EᴀsᴛᴇʀʟʏIʀᴋ haha, that took a few moments=)

TimmyD

Easter was a couple months ago

flawr

19:53

@TimmyD and it will be again in a couple months

Bálint

I need help

I have a very good internet, but becuase of reasons, I need to be at least 30 meters from the router

Thus my current download speed doesn't hit 1MB/s

FryAmTheEggman

"wires"

Bálint

Is there anything I could do about this?

@FryAmTheEggman Oh, also, I have a wall between me and my router

FryAmTheEggman

Drill a hole?

flawr

@Bálint Wrap some auminium foild around antenna?

Nathan Merrill

20:02

@Bálint if your location is fixed, is the router's location fixed?

Bálint

@FryAmTheEggman I don't think they sell 40 meter long cables

FryAmTheEggman

You can attach wires to other wires ;)

Bálint

@flawr I use a small USB based device to have internet

Nathan Merrill

32

Q: How can I boost my wifi range?

I want to be able to connect to my wifi network from downstairs in the garage. My apartment is three floors up, and, while the signal is detectable there, it's very weak. I have tried lifting the laptop up higher. The reason is depicted here: How can I extend the range of my wifi router?

technology wifi

Bálint

Wich is also not very good because I have a PC

flawr

20:04

@NathanMerrill I once made some experiments, was able to reach about 1.5 miles=)

Nathan Merrill

@flawr the real question is what your bit loss rate was

flawr

@NathanMerrill How can you find out?

Nathan Merrill

I can listen to a signal across the world with a 50% accuracy rate

@flawr no idea

Bálint

The router is fix, in fact, some idiot took the net cable (wich goes in the router) and nailed it to the floor

flawr

Well I still had pretty much full speed as if i was just 30 feet away.

Bálint

20:06

It can be moved around in a 2 m area

flawr

@NathanMerrill Nope, certainly not 2.4GHz 100mW

Nathan Merrill

@flawr no, I can. I simply need to guess on each bit, and I'll get it right 50% of the time

Bálint

I try to place some aluminium around the antennas tomorrow, to see if it works or not

flawr

Haha, still nope, you do not find out whether there is a signal at all or not

Bálint

I might buy a signal extender if everything fails

Or a 40 m long internet cable, depends on the price

TimmyD

20:09

@Bálint Sure they do. The maximum single-segment length is 100m for 1000BASE-T connectivity.

Or heck, buy a spool, some ends, a crimper, and roll your own.

Bálint

@TimmyD I would stay away from this method

FryAmTheEggman

@TimmyD People seem to be very averse to using wires nowadays... Spoiled by too effective wireless :P

TimmyD

@Bálint You, personally? Or a general recommendation?

@FryAmTheEggman This is true.

Bálint

@TimmyD I personally

TimmyD

Any particular reason? Crimping your own Ethernet cables is really simple.

Bálint

20:15

It would help, if...I don't know...The router wasn't on the exact opposite side of the house

Nathan Merrill

@Bálint you're talking ethernet cable? do you have access to the modem?

not router*

Bálint

@NathanMerrill No, I'm not a talking ethernet cable

And technically yes, but practically don't

Nathan Merrill

so, the coax cable is nailed to the floor?

Bálint

@NathanMerrill Yes

Nathan Merrill

and I'm guessing there aren't any other coax ports in the house?

Bálint

20:20

I don't know the technical terms, and that bothers me

Nathan Merrill

look for one of these:

to see if you can hook up your modem somewhere else

(simply having a port doesn't guarantee that it'll work, but it often does)

Bálint

@NathanMerrill Sorry, you misunderstood me, I don't know the technical terms, but I know what cable does what

TimmyD

Depending upon pricing, you could run a 40m coax cable with a gender changer on one end. That may or may not be cheaper than a 40m Ethernet cable.

Bálint

I can't change the positioning of the router

Nathan Merrill

why not? is the router nailed as well?

Bálint

20:25

I counted, and I need 20 m of ethernet cable at least to connect the computer and the router

@NathanMerrill No, but my parents use the internet for their job, so they need it

TimmyD

Ah, I had thought the coax cable was the limiting factor in the movement.

Bálint

I try to put some alu around it

@TimmyD It is one of the limiting factors

Because the coax cable is nailed down

Nathan Merrill

if you can't move the router, then the fact that the coax is immovable is irrelevant :)

TimmyD

Precisely.

With the coax being nailed down, you could pop in a female/female RG6 coupler, plunk down another 20m coax cable (or whatever length) and move the router wherever you want.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@flawr :P

Nathan Merrill

20:29

actually, how do coax splitters work with two modems?

TimmyD

If the router itself can't move, though, then your options are a) swap the router for a higher-power model, b) add some aluminium/aluminum foil, c) buy a lengthy Ethernet cable.

@NathanMerrill They don't.

Nathan Merrill

d) wifi repeater

TimmyD

You'd need to negotiate specially with your provider to use a different set of frequencies, else at least one modem wouldn't be able to communicate.

A wifi repeater is an option, but given that we're only talking 20m, it seems egregiously overkill.

flawr

> egregiously

Nathan Merrill

yeah. And while I haven't used them, it seems like it would increase ping more than the other options

TimmyD

20:31

@flawr It's a perfectly cromulent word.

flawr

> cromulent

@TimmyD I just looked it up, didn't know it was an actual english word.

TimmyD

@NathanMerrill It also depends upon how busy the spectrum is in the area, too -- might not have a free channel available to setup a repeater.

flawr

But remdinded me of this

Bálint

I just made 3 siggnal strengthener (aka aluminium folia pieces), let's try it

Nathan Merrill

@TimmyD am I correct that it would increase latency more than the other options though?

Bálint

20:32

I'm curious what my mom will say, when she notices them

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Upgoat are you sure you aren't @Bálint?? :P

/s

Bálint

@EᴀsᴛᴇʀʟʏIʀᴋ ??

TimmyD

@NathanMerrill Yes, but probably on the order of a few ms, likely not noticeable.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

He has bad speleling for the most part.

TimmyD

> speleling

Bálint

20:34

@EᴀsᴛᴇʀʟʏIʀᴋ But I have a reason for it

Eᴀsᴛᴇʀʟʏ Iʀᴋ

yes

Nathan Merrill

wifi is one of my least favorite thing about apartments

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Upgoat types on his iPad.

Nathan Merrill

we have our own router, but we have to compete for channels with other routers

TimmyD

5Ghz for the win

Nathan Merrill

20:35

my computer doesn't support :/

Upgoat

@EᴀsᴛᴇʀʟʏIʀᴋ shit, the cat found out my sock is Ba— idk what you're talking about :P

Eᴀsᴛᴇʀʟʏ Iʀᴋ

10/10 nice coverup

TIL @Bálint is goat.

TimmyD

@NathanMerrill You can buy a nano USB 5GHz wifi adapter for like $15

Upgoat

@Bálint what is? You don't have hooves to blame

Nathan Merrill

@TimmyD router + 2 computers comes to around $80

we're moving soon anyways, so hopefully we won't have as many problems

(aka hoping that people are dumb and are all on the same channel)

Eᴀsᴛᴇʀʟʏ Iʀᴋ

20:40

@Upgoat Non-native-english speaker.

TimmyD

Ah

I run almost exclusively wired

Nathan Merrill

actually, maybe we'll be able to do that with our main computer at home at the new place

I have no idea

TimmyD

mainly because I'm paying for a 150Mbps connection, and that's tough to actually maintain on Wifi at any distance

Bálint

My download speed is half of the one before the aluminium

Nathan Merrill

@Bálint aluminium reflects signal, so it definitely requires tweaking to make sure it points to your computer

TimmyD

20:42

Also, you should be using one sheet, not three little pieces

The idea is to reflect all the Omni-directional signals into a mono-directional signal

From the link Nathan posted earlier:

Bálint

I have three separate antennas

Now, it doubled, awesome

Still less than 3 MB, but at least I can send messages

TimmyD

Depending upon your home electrical wiring, and availability in your area, you could also look at doing a powerline connection

Quill

morning

Bálint

I'm still waiting for fiber, 1 GB sounds awesome

TimmyD

Power-line communication

Power-line communication (PLC) is a communication protocol that uses electrical wiring to simultaneously carry both data, and Alternating Current (AC) electric power transmission or electric power distribution. It is also known as power-line carrier, power-line digital subscriber line (PDSL), mains communication, power-line telecommunications, or power-line networking (PLN). A wide range of power-line communication technologies are needed for different applications, ranging from home automation to Internet access which is often called broadband over power lines (BPL). Most PLC technologies limit...

Bálint

20:46

Anyone knows, how much that cost

@TimmyD I think I just buy a cable

TimmyD

It's totally dependent upon what companies are selling in your area, since it has to account for the style of mains plug and the frequency of the mains electricity.

Eᴀsᴛᴇʀʟʏ Iʀᴋ

@Quill hey!

You are blue now!

Quill

yeah... I woke up to a diamond

10

Bálint

7

Programming resources

Proposed Q&A site for programmers looking after viable resources on different algorithms and techniques.

Currently in definition.

Anyone joining?

El'endia Starman

@Quill \o/

flawr

20:52

@Bálint I don't think they're gonna make another computer/cs/programming/etc SE

Martin Ender

@Quill congrats :)

Bálint

@flawr It depends on how much followers it gets

flawr

Eiffel 65 - I'm blue (official Video)

►

Quill

Thanks @El'endiaStarman, @MartinEnder, @flawr (I think)

flawr

@flawr cannot find that word, can you explain?

Quill

20:54

Cat In The Hat - I'm So Excited!

►

Eᴀsᴛᴇʀʟʏ Iʀᴋ

Any TF2 player help?

TimmyD

Lisa the Iconoclast

"Lisa the Iconoclast" is the sixteenth episode of The Simpsons' seventh season. It originally aired on Fox in the United States on February 18, 1996. In the episode, Springfield's bicentennial approaches, and Lisa writes an essay on town founder Jebediah Springfield. While doing research, she finds a confession revealing that Springfield was a murderous pirate named Hans Sprungfeld who never cared about the people of Springfield. Lisa and Homer decide to get the message out but instead anger the town council. The episode was written by Jonathan Collier and directed by Mike B. Anderson. It w...

flawr

@TimmyD Too bad I watch simpsons only in german.

Thanks for the reference anyway=)

TimmyD

Huh. I wonder how the translation works.

flawr

I do have to admit that I like the german versions even better than the original.

TimmyD

20:58

Well, I was meaning specifically of those two words.

Leaky Nun

Is it possible to solve my challenge in O(log(n)) time?

Finding the denominator of 1/1 + 1/2 + ... + 1/n

flawr

@TimmyD gonna research that

Leaky Nun

@Dennis maybe you can help me

Bálint

@LeakyNun

flawr

@LeakyNun look for the cumulative lcm in oeis

Leaky Nun

21:11

and then?

flawr

denominator = lcm (1,2,3,4,5,6,...,n)

were just adding fractions

do we?

Leaky Nun

I specifically mentioned in my challenge that it is not the cumulative LCM.

El'endia Starman

@flawr I think it's not quite that simple since the numerator might share factors with the denominator.

flawr

@LeakyNun you wrote a challenge about this?

@El'endiaStarman oh right

El'endia Starman

9

Q: Denominator of harmonic series

Earlier, we did the pseudofactorial of a number, which is the LCM of the numbers from 1 to n. It would be useful in adding fractions together. However, we find that the denominator of 1/1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 is 20 instead of the pseudofactorial of 6, which is 60. Your task is to find...

code-golf

flawr

21:21

@LeakyNun perhpas if the abc conjecture holds=)

Leaky Nun

and then?

flawr

@TimmyD embiggen-> "vergranden" cromulent->"allumpassend".

in this case the german ones are probably not that good, but still they'd fit I think

Leaky Nun

I suppose the limit is O(n) [although I still do not have an algorithm for it] because it involves finding the primes below n.

Unless there is a way to form the unreduced fraction in O(log(n))

The numerator would be n!/1 + n!/2 + ... + n!/n

Eᴀsᴛᴇʀʟʏ Iʀᴋ

in The Bridge, 1 min ago, by Eᴀsᴛᴇʀʟʏ Iʀᴋ

Leaky Nun

I suppose forming this one from the last one in O(log(n)) is already good enough.

Bigtoes

21:33

@Quill Are you getting married too??

Leaky Nun

cmc: find and generate the n-th term: 1, 3, 11, 50, 274, 1764, ...

El'endia Starman

@LeakyNun Two possibilities, from what I can see.

Bigtoes

int f(int n){return n<6?new int[]{1,3,11,50,274,1764}[n]:1;}

Upgoat

@Quill :D congrats on Magic shiny quadrilateral

Quill

21:48

@Bigtoes only if Doorknob gets married first

El'endia Starman

@Quill Geez, has your luck with women been that bad? o.O

Quill

lol, and meh

Nathan Merrill

if you were in charge of ordering the alphabet, what would you do?

El'endia Starman

@NathanMerrill Put U and I next to each other.

Nathan Merrill

-.-

mbomb007

21:54

lol

El'endia Starman

Please tell me you knew about that joke beforehand. :P

Nathan Merrill

I did

El'endia Starman

Okay, good. :P

Nathan Merrill

AEIOUYMBPNDT

mbomb007

I would leave the alphabet in its current ordering.

Nathan Merrill

21:55

C is tough. do you pair it with S or K?

mbomb007

Both.

HSCK

Cᴏɴᴏʀ O'Bʀɪᴇɴ

this is a good question

Nathan Merrill

AEIOUYMBPNDTKCSX

I'm not sure why you included H there

Bigtoes

@NathanMerrill You get rid of C altogether, or possibly make it the CH sound alone. S and K work to make it redundant.

Nathan Merrill

@Bigtoes nope, we can only reorder

mbomb007

21:57

@CᴏɴᴏʀO'Bʀɪᴇɴ I haven't played TF2 for a couple/few years.

Bigtoes

@NathanMerrill Meh. That's a half-ass job I want no part of :P

Cᴏɴᴏʀ O'Bʀɪᴇɴ

@mbomb007 you should play it it's really good

Nathan Merrill

@Bigtoes it's the job of conforming an unstandardized system into a more regular one

mbomb007

@NathanMerrill S and H goes together often. Maybe go TSHCK...

Upgoat

@Quill can you make the pro term post featured with your newfangled blueness

El'endia Starman

21:58

JavaScript regex mini challenge: match one optional comma with any number of spaces afterwards, but not nothing. (Hint hint @CᴏɴᴏʀO'Bʀɪᴇɴ. :P)

mbomb007

@CᴏɴᴏʀO'Bʀɪᴇɴ It's the same as it has always been. 2Fort everywhere.

Bigtoes

@NathanMerrill Which is half-assed imo, because you should eliminate redundancies in the system at the same time.

Nathan Merrill

well, I like S and X together because they are so similar sounding

Bigtoes

Yea, you don't need X either. It's either ks or z sound.

Nathan Merrill

but that's the thing about standards. You can't just drop what you don't like

mbomb007

21:59

Yeah, we have standards.

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