/dpt/ - Daily Programming Thread

>>57078072
keep posting my bf, i mean gf

a .c must contain a main?
a .h can contain structs, prototypes, and even a function too?

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>>57078072
How do I program things like menus?
Think in game menus where you navigate through the them and they light up and stuff.

I just don't know where to begin. But it's something I wanna do.

Can anyone point me in the right direction?

>>57078125
>a .c must contain a main?
No, but an executable must contain a main

you can put anything you want in a header file, but this is poor form.
You need to think of every .c file as a translation unit.
A header's purpose is to make visible declarations that other files will depend on.

So basically, you should only use it for macros, structs, enums, and function prototypes that other files need to know about.

>>57078125
> a .c must contain a main?
nope. libraries and such. When linking you can only have one main().

gcc -c lib.c
gcc -c main.c
gcc lib.o main.o -o mybin

> a .h can contain structs, prototypes, and even a function too?
A dot h file can contain whatever you want, it's just a convention to put forward definitions in it, but it is vanilla C code.

>install W10
>start menu search box breaks immediately

Now that's what I call quality

>>57078185
>works_on_my_machine.jpg

>>57078195

Classic shell is better, anyway, and the search works.

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I made what the other guy did last thread, but in Clojure.

>>57078161
What is is style of having structs/classes in a .c/.cpp file and function definitions in a .h/.hpp file?
All the bigger projects use this layout, I'm just putting everything in .h files and the only .cpp file is the main program. K&R never touched on this.

>>57078265
:)

post code

ayy gibbe the discord :DD

>>57078212
this

holy shit what the fuck is up with microsoft's search

why cant it search anything

>>57078281
Well, in a normal program, you have your code separated by what they do.
For example

main.c input.c graphics.c network.c

You would assume that main.c uses extern functions from every other .c file, and so has

#include "input.h"
#include "graphics.h"
#include "network.h"

Each of them contain extern function declarations for things that aren't declared in main.c, but main.c uses anyway.
This isn't a problem, as this is resolved during linking.
You're basically telling the C compiler, that these things exist somewhere else and will be available during the linking step when it builds your executable.

>>57078295

(ns amuro.ray
  (:require [clj-http.client :as client])
  (:require [cheshire.core :refer :all])
  (:require [clojure.string :as str]))

(def handicrafts-url "https://en.wikipedia.org/w/api.php?action=query&list=categorymembers&cmprop=title&cmlimit=500&cmtitle=Category:Handicrafts&format=json")

(defn json-body
  ([url] (json-body url nil))
  ([url arg] (:body (client/get url arg))))

(defn slur-titles [json]
  (map #(% "title") (((parse-string json) "query") "categorymembers")))

(defn filter-slurs [s]
  (filter #(and (str/ends-with? % "ing") (not (str/includes? % ":"))) s))

(def slurs
  (->> handicrafts-url
       json-body
       slur-titles
       filter-slurs
       (into [])))

(def countries-url "https://restcountries.eu/rest/v1/all")

(defn countries-json [url]
  (parse-string (json-body url {:insecure? true})))

(def asian-demonyms
  (into [] (map #(% "demonym") (filter #(= (% "region") "Asia") (countries-json countries-url)))))

(defn print-result []
  (let [demonyms-slurs (zipmap (shuffle asian-demonyms) (shuffle slurs))
        k (keys demonyms-slurs)
        v (vals demonyms-slurs)
        type ["image board" "message board" "forum"]]
    (dotimes [n 10]
      (println (nth k n) (nth v n) (rand-nth type)))))

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I just picked up Scheme the other day and I've been enjoying it so far. Here's a few functions I wrote to try practicing with recursion: http://pastebin.com/7mNB9HgG

Anyone care to give me some advice on how to improve these?

>>57078297

https://discord.gg/5KNnT

>>57078441
literally for what purpose

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>>57078491
For fun of course!

>>57078407
Clojure has some of the most disgusting syntax ever made. It's like python mixed with lisp

>>57078501
you can be productive instead...
don't you have projects to work on? wtf

>>57078528
Yeah, but it belongs strictly in wdg. I've been messing with Scheme in my free time

Im doing a simple bash script that asks the user for a name to create a directory but im getting this error

mkdir cannot create directory '': no such file or directory

my code looks like this

read $varname

mkdir "$varname"

any idea what might be wrong?

>>57078585
aaaaaaaaaaaand I figured it out literally 10 seconds after asking this

was using " " instead of ' '

>>57078591
but now my directory is name $varname instead of what the user inputs lol

>>57078591
and OP is a fag for not linking before you ask instructions

>>57078137
What language? C++ and OOP sounds like what you need

>>57078351
Thank you, this is a god damn good post. Still don't get how this makes life easier though, don't see why input.c couldn't just be put in input.h, but it does look cleaner and everyone's doing it so oh well, migh as well.

>>57078072
I'm a student working on conversions between bases. Dec to binary was easy, Dec to hex gave me some issues though due to ASCII tables.

I'll post code if thread is still up when I'm home in a couple hours.

I also have to do hex to binary, how would you guys go about doing that?
Convert to Dec first and then convert to binary?

Any help is welcome, thank you.

>>57078614
that literally says nothing about how to do it

>>57078652
Look it up yourself. Start by looking for "gui c++ library" or "graphics c++ library" and then implement your own simple menu code.

>>57078650
Forgot to mention, I'm using C++

>>57078137
In games? You probably need some sort of window handler, I recommend GLFW, then do it with OpenGL and C++.

But that is very long and tedious. I write game engines and honestly, take my advice if you're a gamedev, just use UE4/Unity for this stuff. OpenGL/C++ is just for the math and performance nerds(like myself).

>>57078676
How do you like Unity? Heard it's renderer is pretty shit tier.

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>>57078675
Hex to binary is easy, so easy.
For each hex digit, just output the four bits.
> 0 -> 0000
> 1 -> 0001
>2 -> 0010
...
>9 -> 1001
>A -> 1010
>B -> 1011
...
>F -> 1111

So B09 -> 110100001001
Easy.

>>57078691
>How do you like Unity?

Haven't tried it, no idea. Though I recommend Unity/UE4 for anyone into gamedev. I don't recommend going off straight into OpenGL, unless you're interested in mathematics and stuff, it takes way too long to actually make a good engine in OpenGL/C++ if you don't know OpenGL.

I always thought using Unity/UE4 would make me inferior to all the nitty gritty programmers like John Carmack, so I've been doing this for 2 year now. I enjoy it but using Unity/UE4 should not be a sign of inferiority, but a sign of superiority in how fast you can get games done.

>>57078817
>John Carmack
how do I get this good ;__;

>tfw I keep getting extremely java-specific questions in interviews that I can't answer

fuck this noise

>>57078864
i'm a little worried about this too
i've mostly been using go these past few months. that'll be fine at google but probably nowhere else

>>57078893
haven't seen a single employer looking for a go dev
why are you memeing

>>57078893
Python and JS are my strong suits, but there are just too many java jobs to ignore, and I haven't used java in 3 years

>>57078851
By programming, I believe. I'm at the point where I can relate to his talks allot from my programming experience(so much I'd rather watch his talks on aerospace). What's unique about Carmack is how he is always pushing the limit.

>>57078639
Putting the code for your functions in separate .c files allows you to compile them separately, so if you change one of the files, you only need to recompile that one.

>>57078948
Holy shit, really?
Long and behold, my 2 second compile times will come to an end!

>>57076749
I tried simulated annealing.
Other than the reverse-swap move operation being slow as balls, and a questionable heuristic, especially for such a huge graph, there wasn't much difference.
I found out that the solution I have has more or less already converged, but it isn't good enough for some reason.
I don't really understand.

>>57078722
Hmm. Thank you anon.

>>57078691
Unity runs like absolute shit. i understand the draw for beginners because it's easy to use, but i get so mad when i see how bad a given project runs knowing the same project implemented in any other decent engine or framework would run a shitload better. some of that is on the devs, especially given a lot of them aren't very experienced, but i've played Unity games by very skilled devs that still ran shockingly bad for what they were. and from what i've gathered, improving performance often involves hacking around Unity functionality, at which point what the hell is the point?

>>57078817
>I always thought using Unity/UE4 would make me inferior to all the nitty gritty programmers like John Carmack
that's because it does, if you never move on. i understand not wanting to dive in the deep end, but the problem is that a lot of people get too comfortable using these easy middleware solutions and never bother to learn how they work under the hood, or really learn anything at all except what's strictly required and at the highest level of abstraction they can possibly find (to the point of shit like paying for a plugin for A* pathfinding - don't even fucking get me started on that). the thing is, yeah, i guess these days you don't *technically* need to learn those things if they're just available to you like that. but if you never learn the fine details, you're never really going to be a truly good or exceptional developer

>I enjoy it but using Unity/UE4 should not be a sign of inferiority, but a sign of superiority in how fast you can get games done
there's no shame in starting out with something like that as long as you commit to continuing to learn so you don't stagnate. but i disagree with that second part, and i think that the growing popularity of that sentiment has been terrible for the indie games community. that's like saying knowing how to operate a microwave is superior to knowing how to cook because it gets the job done faster

>>57078915
oh i'm not playing with it for employability i just think it's fun
these things are supposed to be mostly algorithms so i hope it won't matter too much

>>57078996

You are only compiling small programs. Larger programs take longer to compile. Similarly, they are harder to maintain, especially if everything is in the same file.

Is ASCII different on linux or something?

I'm trying to convert some character numbers from an array into their integer counterparts, so for '1' I have

int i = '1' - '0'

and when i compile on my system, that gives me a 1, but if I try to compile on my university's Linux server, I get a 0 instead.

However, every other number comes out just fine...

Im currently finnihsing up some Java assignments, just started getting into OOP

>>57079061
>but if you never learn the fine details, you're never really going to be a truly good or exceptional developer
Truth, but it's not about being a developer, it's about having an interface to create art. You see, an artist should not need to spend hours trying to get OpenGL working, it's the job of us developers to make a good solid interface for artists so they can create freely, that's Unity and UE4. Yes, there's allot of shitty games on Unity and UE4, but I guarantee those games wouldn't be any better if someone spent hours making them in OpenGL/C++, maybe more impressive, but the (art) is what counts

>but i disagree with that second part, and i think that the growing popularity of that sentiment has been terrible for the indie games community. that's like saying knowing how to operate a microwave is superior to knowing how to cook because it gets the job done faster
I feel like Unity/UE4 engines are like a car, OpenGL/D3D are like a jet. It has always been about us 3D developers giving the maximum freedoms to artists, and that's all Unity and UE4 are about.

If writing OpenGL is some sort of "elitism", might as well write C64 demos your whole life.

>>57079194
nice, get yourself a 100k job already

>>57079198
The potential quality of the art is almost instantly bottlenecked by the interface and the algorithms behind it.

>>57079219
what is that in rupees

>>57079244
Maybe in Unity, granted, but have you seen UE4 in action? I'm rather impressed with their visual scripting stuff, render effects and visual shader/post process composing, I've programmed some sort of visual post process composer and damn, having something like that so useful. I wouldn't say UE4's potential is bottlenecked by it's interface at all. UE4's interface is fucking awesome.

>>57079182

man ascii

>>57079182

#include <stdio.h>
#include <assert.h>

int main()
{
    char str[] = "0123456789";
    int i;
    
    for (i = 0; i < 10; i++)
        printf("%hhi\n", str[i]);
    
    assert('1' - '0' == 1);
    
    return 0;
}

>>57079352
>>57079310
I figured it out, there was some weird shit that handled negative cases wrong that I forgot to remove.

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github or gitlab?

>>57079024
I might be that there just exists no algorithm that has the accuracy/performance characteristics you seek unless P=NP.

>>57079462
clearly there is, otherwise I wouldn't be failing this assignment

>>57079495
So wait a minute, this is for an assignment and you've tried all these algorithms and NONE of them have worked for you?

What's the specific requirements of time complexity/(potentially average) approximation ratio for the assignment? Or is it specified a different way?

Are you sure you're not measuring your own results wrong?

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generate a mandelbrot set in your favorite language /g/

Hi guys, I am confused on a "simple" C concept. It is about passing by reference vs passing by value.
Can a function change the value of an specific array element? Ex. array[2]. I have read in a book that you can't, but then I saw a video where it showed that you could. Color me confused.

>>57079450

Neither.

>>57079564
Forgot to link the video to make my question easier to understand.

<iframe width="560" height="315" src="https://www.youtube.com/embed/7EdaoE46BTI" frameborder="0" allowfullscreen></iframe>

>>57079564

Everything you pass is a value, it's just that sometimes, those values might be the address of an object stored somewhere else.

>>57079519
The approximation is supposed to beat several algorithms that operate on a test case. There's no time complexity requirement. Just get it done.
The approximation ratio is unknown, but I get a better grade as I beat more algorithms.

My question is what kind of god-king algorithms have been employed to beat Christofides, SA, and ACO.

>>57079198
>an artist should not need to spend hours trying to get OpenGL working
i hear you. there's a balance to be struck. but let's just say that Unity is... not exactly nailing it. i'm certainly not such an elitist that i think that every dev should have to work directly at the lowest level all the time. in fact, once i'm done with my current project, i'm going to start working full-time on a robust cross-platform open-source game development framework that i've been designing for some time. it will be composed of increasingly higher-level optional modules on top of an efficient and low-level but intuitive and consistently designed base that can and should be used on its own if you don't want or need the frills. that way people choose their own level of abstraction

>it's the job of us developers to make a good solid interface for artists so they can create freely
i don't see it as a separate thing. you may not need to go super low-level to be a good developer, if you had ideal tools at hand, but i think you do in order to be a truly exceptional developer. my passion for programming initially came from my passion for games as an artistic medium. i wanted to be very technical because i wanted to be able to actually innovate new technologies, not just mix together existing ones in slightly new configurations, because that's what really pushes the medium. ideas do not occur in a vacuum, and ideas for mechanisms have often occurred to me from the bottom up, such that i'm sure i would not have thought of them if i didn't have a low-level understanding of various other mechanism

>>57079646
So what, you send your code to their server, it runs your code and compares to its own, and you silently get a result? How much real feedback do you get?

>>57079706
Yep. Nail on the head.
Feedback is "Your output is wrong in this way, fix it"

>>57079714
So do you get your approximation ratio and the runtime, then? What is that compared to the reference?

>>57079198
>>57079691
(cont.)

>there's allot of shitty games on Unity and UE4, but I guarantee those games wouldn't be any better if someone spent hours making them in OpenGL/C++
that's the one thing that makes me feel better about it; the main reason the market looks so bad right now is simply that the barrier to entry has been lowered. make things easy enough and you're bound to see an influx of low-effort shitpiles. it's just a shame that the added noise can drown out decent stuff. we just have to hope the available distribution platforms and consumers do and continue to do a decent job of curating and elevating the genuinely good stuff. and yeah, it's not like most of these devs would have been the next Carmack if not for Unity or something, but i just worry a potentially good technical dev could end up going with middleware for economic reasons and then possibly stagnating because there's less motivating them to dive deeper

>>57079714
As a last resort, I'm running 2-opt on this 100,000 point graph.

>>57079743
Oh, no I run my own code on my own PC. Sending code to run on the server would be silly, as the first thing I would do is try to root the server.

I essentially have zero information except for the problem and the instance of the problem that we're given.
Since it's 4D, I can't visualize the graph, which sucks.

Is there any book or article that explains good programming practices? Like why you should put return(0) at the end of your program in C, even if it's not strictly necessary, or why you should link stuff like in >>57078351.
What I usually find is stuff in StackOverflow, but I don't want to learn that stuff drop by drop.

I've read "97 Things Programmers should know" and "The Elements of Java Style". I want a book like that, but for C.

>>57079760
Well, you can sandbox code really easily these days. (vms, docker, chroot, seccomp, etc) There's all sorts of interview prep sites that run user code as their primary product. Maybe your PC just sucks, or there's bugs in your code? There's no way you're expected to write something better than all the things you've already made.

>>57079800
"good programming practices" is the end result of understanding everything about your computer architecture, operating system quirks, programming language design concepts, and pretty much everything you can think of, that interfaces with your program.
I don't know if there's a book on the subject, but the default way to understand it is to just learn everything, and then good programming practices become intuitive rather than learned.

>>57079800
>Like why you should put return(0) at the end of your program in C, even if it's not strictly necessary

You shouldn't. It's the current year.

>>57079198
As a side comment: don't use Unity. It sends user data from players to Unity with no way for the developer or the user to turn it off.

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So I'm working on this program for school where we calculate a Fibonacci series using using two pointers to integer arrays that add into each other through a loop. I've got it working, and it calculates everything pretty fast, but once it goes slightly above 71000, all it returns is (null pointer).

Anyone know why that might be happening?

Sorry if none of that made sense, I'm kind of talking out of my ass here...

>>57079856
When I say above 71000 I mean F(71000) where F(n) is the Fibonacci series.

>>57079564
>Can a function change the value of an specific array element?
Sure.

#include <stdio.h>

/*
 * Takes a pointer to an int and writes 3 to that address.
 */
void foo(int *ptr)
{
    *ptr = 3;
}

int main(void)
{
    int array[4] = { 2, 4, 6, 8 };

    /* We pass the second element by taking it's address with the & operator */
    foo(&array[2]);

    printf("array[2] is now: %d\n", array[2]);
    return 0;
}

>>57079826
I see. Thanks.

>>57079829
I once caused a segfault with that. I don't even know how.

>>57079856
So, why are you using an array exactly? The iterative Fibonacci solution only requires two variables.

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>>57079875
>second element
I meant third element of course.

>>57079842
But I like the store and the copy-paste tutorials.
My platformer is already 40,000 lines long.

>>57079856
What is the loop condition?

>>57079883
i imagine to store results that you've already calculated to make them O(1)

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>>57079533
python3

import struct
P = struct.pack
v, x = 750, 500
C = range(v*x)
_ = (
    255,
    lambda V, B, c: c and Y(V*V+B, B, c-1) if (abs(V)<6)
    else (2+c-4*abs(V)**-0.4) / i
)
M, j = '<QIIHHHH', open('M.bmp', 'wb').write
for X in j(b'BM'+P(M, v*x*3+26, 26, 12, v, x, 1, 24)) and C:
    i, Y = _
    j(P('BBB', *(lambda T: (int(T*80+T**9*i-950*T**99),
                         int(T*70-880*T**18+701*T**9),
                         int(T*i**(1-T**45*2)))
                        )
            (sum([Y(0,
             (A%3/3.+X%v+(X/v+A/3/3.-x/2)/1j)*2.5/x-2.7,
              i)**2 for A in C[:9]])
            /9)))

best scripting language? ones that can be run on most systems without having to install extra stuff is a plus

>>57079883
I guess my professor just wants to give us busy work.

>>57079875
>>57079887
lmfao, thanks for the explanation man. I guess the book that I read that from made a mistake, oh well.

>>57079931
how will you know the index to the array though?

>>57079981
the number you're computing f of?

>>57080004
in that case just return the fibonacci number or allocate it in memory wtf

>>57080027
yes...?

>>57079931
You only need one pointer and one array to do that though.

Why do you think people rarely talk about the workplace/career development at /dpt/? I don't see anonymized resumes or salary discussion much.

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>>57080289

>4chin
>workplace/career development

>>57080120
yeah i know, nerd

>>57080309
shuddup, dork

>>57080289
From the vibe I get coming into these threads a lot of people are either learning how to program or are still on the path to getting that career. There's also something to be said about all the hobbyists out there that just want to make some cool stuff for fun. If you have any questions I could try and answer them.

>>57080289
amateur central

>>57073828
... because there's no reason to?
are the config variables mutable?
if so, why? why not simply have them as a parameter?
if not, why do they need to be in a class?

>>57080289
I'm almost graduating. When I get a job, I probably won't stop posting here.
But at the same time, I almost certainly won't talk about what I do at work.

>>57080373
>When I get a job, I probably won't stop posting here.
sure thing

>>57080381
>>57080373
lol i read this as "I probably will stop posting here."

did hiroshima remove the ability to click post and have it automatically post when your cooldown is up?

what can lisp do?

>>57080399

>>57080399
slow you down from actually getting projects done and not just memeing for lulz im special

>>57080054
Oh. You're doing Big Integer addition.
Well, deal is, the 71000th Fibonacci number is bound to be fucking huge.
You need to figure out the number of digits in the 70999th Fibonacci number (or the highest one that actually works).

>>57080412
ironic http://www.paulgraham.com/avg.html

>Big Integer
fucking hate this term
stop fucking using your OOP bullshit phrases to refer to everything like a fucking child

>>57080423
>muh n-digit mathematics
Face it, fagtron, "arbitrary length integer addition" is an ass description for what is conceptually something that newfag programmers aren't going to find intuitive.

>>57080438
How about just fucking "integer" you fucking dumbass?

is C++ the next language after C? Or should I learn Java right away?

>>57080420
but I am not a genius and neither are you
we rely on libraries and algorithms geniuses make

>>57080442
Because integers have fixed bit width you fucking retard, and you need to be descriptive when you're working with arbitrary length integers.
Did you know that math with fixed-width integers and arbitrary length integers have a different Big O bound?
I bet you fucking didn't because you're a fucking retard.

>>57080446
want to work with games or hardware? c++
no? java

also if no, why did you study C

>>57080460
My answer is yes. Just wanted to know what i should be learning next after mastering C. Thanks anon. Is java still worth learning tho?

>>57080455
You are so wrong

>>57080455
Oh yeah, like how in mathematics you always fucking talk about bigints and arbitrary numbers

You've dug your own whole if you refer to bounded integers as integers. Just call them ints you fucking idiot.

>>57080469
considering pajeets are taking over java meaning the average wage of java programmers are going down, no

>>57080481
>pajeets are taking over java
Is this some kind of Java caste war?
Are the Java Sikhs and Java Hindus about to fight it out?

>>57080308
I know, I know - you can't expect much, but I've seen competent developers here, who definitely have jobs in the real world or are between internships in college like me.

>>57080329
>>57080339
Yeah, that's true. I often try to help with things I can easily answer as well.

>>57080373
>I almost certainly won't talk about what I do at work.
Why not? You can fully anonymize most of those types of stories fairly easily, and withhold the rest. Do you think those types of discussions aren't interesting?

>>57080481
Oh cool, so that means that C/C++ are pajeet's free languages? Even more of an incentive to learn master them. Thanks anon.

>>57080472
Even Wikipedia has the Big O runtime complexity of addition and subtraction (hint, it's O(n)). Go fuck yourself.

>>57080474
Anyone doing math isn't so stupid that they don't know the concept of fixed-precision datatypes.
It'd be the first roadblock they run into in the runtime of their statistics programs

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>>57080505
there are an unlimited number of pajeets ready to take over all languages

nobody is safe

>>57080513
please delete this ;___;
ill have nightmares tonight

>>57080513
>tfw India wasn't taken over by commies so that they could institute a 1-child policy
If they had done it 50 years ago, both they and we wouldn't even be having these problems.

>>57080510
it's simple
>integer (arbitrary precision)
>int (fixed precision)
>int8 (8 bit)
>int16 (16 bit)
>etc

>>57080513
Do underdeveloped countries that get easy access to first world resources (India, China) always end up like that? Christ.

>public class MyClass {
>...
>}
and
>class MyClass {
>...
>}
What's the difference?

>>57080547
linkage

>>57080539
Yes.
We were like that once, too. Difference is, that was the height of the industrial revolution.
The industrial revolution was long enough that population effects were distributed over time. As we evolved from an agrarian society, where the emphasis was placed on many children, to an industrial society, where less children were needed, the stress to industrialize as quickly as possible wasn't present like it is in China and India.

You see those population trends in all agrarian societies that are facing industrialization.

>>57080547
>class MyClass
they are only in the scope of the package
so you can't inherit if its outside the package

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>did calculations on how long it would take to brute force 2-opt on 100,000 points
>55 hours
>mfw

any lisp programmers here
any tldr books that don't assume I've never programmed before???

>>57080599
Programming Language Pragmatics jumps right in

>>57080599
(function parameter1 parameter2 ... parameterN)

congratulations, you know lisp

for real though, there's only a handful of things that differ from this. just read a manual

>>57080592
Why do you need to do that 2bh?

>>57080647
grasping at straws on ways to optimize a travelling salesman tour

>>57080655
just get lucky first try

>>57080655
Well that I figured out.

Why do you need to do a traveling salesman algorithm for 100,000 points?

>>57080674
class assignment
refer to >>57079760
>>57079714
>>57079646

>>57080549
Completely wrong and not even relevant to Java.
>>57080582
Correct.
>>57080568
That's interesting anon; thanks.

>>57080694
Your class assignment is to solve the Traveling salesman problem with 100,000 nodes?

Wtf kinda class is that?

scheme vs common lisp, go!

>>57078072
quote posting that stupid image, why would you NOT cast the return value of malloc for gods sake?

>>57080755
It's the class where you learn to deal with NP-complete problems.
You'll find yourself solving problems like Vertex Cover, with shit-huge amounts of data, so you can't cheat the Big O complexity like the fag algorithmicists do by making adjacency tables

If it's unrealistic to get an exact answer, you have to approximate it.

>>57080784
Because there is literally no reason to, and all it does is duplicate information.

>>57080705
>>57080582
Thank you sempais.

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>>57078265
did this in python.

>>57080784
this
like wtf

>>57080784
Every time I see that I'm like, "How could you learn about malloc() without learning about casting its return value as necessary?"

>he doesn't cast the return value of strlen

how do I get a qt programmer bf ;__;

>>57081164
lol fag

>>57081164
crossdress and get a job at any bay area startup
you''ll be hired immediately

then you'll be surrounded with programmer qts

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>>57080599
https://ds26gte.github.io/tyscheme/
https://learnxinyminutes.com/docs/common-lisp/
www.braveclojure.com

>>57080446
Javascript

>>57080399
Lisp being a programmable programming language, you can do almost everything.

>>57079959
perl, python, ...

>>57079875
>* Takes a pointer to an int and writes 3 to that address.
>taking it's address with the & operator
& doesn't return an address but a pointer, the difference is important.

>>57079800
uncle bob's books
sicp

>>57079450
Neither.

https://gitla.in/
https://gitgud.io/

>>57078441
Use an inner procedure to avoid passing invariant arguments. It's also odd that you recursively pass a list to just return it's car value at the end.

>>57078137
When you think about it, a menu is just a list of buttons with a selector.

Use these tutorials to learn how to implement a system for buttons
http://sol.gfxile.net/imgui/index.html
http://www.trackze.ro/

>>57078125
No.
Yes.

>>57078072
Thank you for using an anime image.

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>>57081249
reply to me pls senpai

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>>57078072
Are there any limitations to programming in Lua on Windows? Will I have problems with the C API and libraries if I have MingW and the latest GCC?

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>>57081249
>>57081358
senpai?

>>57078125
Header files are a convention that make it easier to write and read code. You don't HAVE to use them.

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>tfw turning in programming homework and it's apparently all wrong even though it works as intended

>>57081481
>goes onto hard coding fibonacci

>>57081481
"It didn't compile on our machine that you have no way of accessing" or "You didn't do it in this way so you're retarded"?

Dropped a class that did that. It was python, which makes it even dumber.

Tangentially related funny note, had programming homework once and the professor's starter code for it was riddled with logic errors. I threw it all out and just made 9 bool functions. Got 100% on that one.

>>57081501
>"It didn't compile on our machine that you have no way of accessing" or "You didn't do it in this way so you're retarded"?
The latter. The website the class uses is spotty as fuck, and if you don't type it EXACTLY the way they think it's supposed to be then it's not counted as correct. I've had problems with it since I first started taking the class, even the simplest shit I get wrong because it's so spotty with the answers.
>the professor's starter code for it was riddled with logic errors.
This was actually the case with a problem I had earlier.

>>57081530
>website
that's the fucking worst. Luckily my classes allowed resubmissions for those cases.

>logic errors
I had one professor that people always made fun of cause he was clumsy and would make a shitload of syntax errors. Logic was always sound. Few ever complained about another professor that made a bunch of logic errors.

Guess which one is more of a pain in the ass to debug.

>>57078441

Several comments:

Not all of your functions are tail recursive. Tail call optimization can only happen if they are. It can sometimes be a bit trickier to write functions this way (hint: use an accumulator parameter in a helper function), but it is a common thing for space efficiency and reading other people's code.

More importantly, all of these functions can easily be written with the empty list as the base case. Not only is that simpler and more mathematically pleasing, it avoids calling (length) on every iteration of the function, and takes you down from O(N^2) to O(N) run time. Writing the way you've written them also means you don't handle the very common case of an empty list. Example, look at what (my-reduce) does with a list of length 2.

You might benefit from working through The Little Schemer.

>>57080793

If optimality isn't required, just use a greedy solution. Keep a set of unvisited nodes. For every node, next node is the closest from the unvisited set. For better results, try with every possible starting point, you're still in polynomial time.

>>57081547
>my classes allowed resubmissions for those cases.
I hope I won't get this shit counted against me. I actually misses the deadline because I couldn't figure out what I was doing wrong. I was supposed to go to sleep around 5 hours ago but I didn't want to stop until I was 100% sure my programs were working, I finally emailed my professor about it a few minutes ago.

>>57081582
good luck. If nothing else, try going to your professor and/or ta's office hours. Will show that you actually give a shit about the class which helps more than you'd think.

Good morning dpt

>>57081744
hey bb gurl :3

>>57081164
Download qt creator :^)

>>57081393

Considering that the latest Lua builds are made with MinGW, no.

>>57079198
An artist wouldnt touch open gl. Thats why there are programmers

>>57081792
k

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I'm rewriting a code in Python for Google Merchants. It was originally written in PHP but it seems to not work as well anymore.

Here is snippet of what the original person wrote.

>>57081831
That's the shittiest code I've seen this week.

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>>57081751

>>57081831
MY EYES

>>57081818
As a coder, i get frustrated when the artists keep talking about shaders. I have no idea what they're talking about, because it can not be what i think of when talking about shaders.

>>57081831
Burn it with fire!

>>57081831
This can't be real.

>>57081831
>or or or or or or
are you fucking obama?
>if if if if if
this is fucking pathetic

>>57081854
>I have no idea what they're talking about
From the artist's perspective, a shader is pretty much like a material you apply to geometry. Not very complicated.

>>57078614
>Needing OOP to draw GUIS
IMGUI master race

>Google interview
>Google is retarded

http://www.gwan.com/blog/20160405.html

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My first pull request got accepted. Good feel.

>>57081960
>LINUX TRIVIA WILL GET YOU A JOB AT GOOGLE

I am mad.

>>57081893
That would make it my job to allow them to do that. But i have trouble enough with single shaders, let alone making different shaders play nice together.

>>57081992

>Quicksort is the best sorting algorithm because it has the best Big O
I am mad. Quicksort is only O(n log n) in the average case. Worst case, it's O(n^2). Meanwhile, there's probably a few dozen or so sorts that are O(n log n) in all cases. A popular sort used in the standard libraries of a few programming languages is Introsort. This uses Quicksort for most cases, but falls back on Heapsort if the recursion depth for the Quicksort goes too deep. There are also sorting algorithms like Timsort (used by CPython), which manage best case linear time, while still maintaining log-linear average and worst case times.

I get the sense that the interviewer in this story was not a computer scientist.

Still writing the btree. A bit slacking with the deletion. Gotta write tests and all. Insertion works ok. Gonna translate this to C after I'm done with it.

http://paste.debian.net/877639/
http://paste.debian.net/877640/

>>57082048
Really the answer to that one was pretty obvious. Yes the dude asking it, if he really did, asked it in a stupid wrong fashion but everyone knows why quicksort is the go-to sort.

Hey guys, I'm making a web scraper in Java and I want to try multithreading.

I have 10-20 links I want to scrape and return that many objects and put them into an ArrayList.

How would I implement those 10-20 links being scraped independently and adding the objects to the list when they're ready?

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>>57082054
>1700 lines of code for a b-tree

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I'm a dumb nigga but still...
What's Prolog created for?
Any guide for retards?

>>57082069
Second file is tests. Leaf and non-leaf are handled differently.
Also, there's a lot of comments since I want to write a C version later and don't want to rethink the details much. The difficulty are the index calculations which is why tests.

>>57082069

in Haskell this is just

data Tree a = Empty | Split a (Tree a) (Tree a)

>>57082125
That's not a b-tree.

>>57082136
pattern Leaf x = Split x Empty Empty

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>>57081983
>make pull request
>closed because changes are "out of scope"
>1 week later, he pushed a commit that had most of my changes, but rewritten so he could take credit

>>57082216

That is still not a b-tree. Try something like this:

https://github.com/jaspervdj/b-tree/blob/master/src/Data/BTree.hs

>>57082318
It's a potentially empty binary tree

>>57082334

A b-tree is not necessarily a binary tree. Indeed, it is a generalization of a binary search tree and can have more branches if need be. But regardless, it has one mandatory component, which is that it is self-balancing.

You haven't shown any code for self-balancing, thus, a b-tree it is not.

>>57082364
Oh, I thought b-tree was short for binary tree

>>57081960
>http://www.gwan.com/blog/20160405.html
The popcount one is funny, especially considering that books from Google itself show demonstratively that Kernighan and Hacker's Delight popcount are faster than a table solution.

>>57082400

It isn't.
https://en.wikipedia.org/wiki/B-tree

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>return a boolean of whether or not the name has the same first and last letter

How was this even a question
Python

return name[0] == name[-1]

Js

return name.shift() === name.pop()

Does anyone have more of these questions?

This is a function based of a Codewars kata that takes as input any amount of numbers, and produces the greatest palindrome, using the numbers of the product of arguments.

function numericPalindrome(...theargs){
    var arr = theargs.reduce(function(a,b){return a * b}).
    toString().split("");
    //multiplying the arguments
    var doubles = arr.filter(function(num){
        return arr.lastIndexOf(num) !== arr.indexOf(num);
    });
    
    doubles = doubles.splice(0,doubles.length / 2).
    sort(function(a,b){return b - a});
    //in order for a number to be a palindrome, there would need to be two of them. (though with this I'm forgetting instances where there are more than two of a given number). I only need in the individual numbers, not both of them, and I sort them from greatest to least
    var highest = arr.filter(function(num){
        return doubles.indexOf(num) === -1;
    });
    //the numbers that aren't in the doubles, going to go in the middle to make the number larger
    if (highest[0] === undefined){highest = ""}
    else {highest = 
    highest.reduce(function(a,b){return Number(a) >= Number(b) ? a : b})}
    //if there are no numbers beyond double numbers, give highest the closest thing to an empty value I can give, else return the highest number
    return Number(doubles.concat(highest).concat(doubles.reverse()).join(""));
}
//concatenate doubles and highest, then concatenate that to the reverse of of doubles to make it palindromic
//join it together and make it a number

This took me like 30 mins of mostly thinking about it. I'm missing a few building blocks or I would've been able to chain most of the entire things with higher order and anonymous functions.

>>57082216
>using crappy non-standard extensions
View patterns are the most harmful thing since goto.

>>57082727
>view patterns
That's pattern synonyms, actually.

>>57082727
>>57082816
And pattern synonyms is a lot more restricted than view patterns.

Can i make a variable temporarily constant?
I mean something like toggling write protection on or off on the variable?
Using c++.

>>57083031
T value;

const T& constView = value;

>>57083031

Toggling OS write protection generally occurs on an entire page of memory, not just the memory used by a single variable. You can assign a constant to the variable, or pass it around by const or const reference, and guarantee compile time that it's not going to be fucked with (probably), but if you start fucking with memory permissions, you're going to be asking for some pain.

>>57083132
>>57083149
None of these seem to be really what i want.

I think i'm going to have to write a getter and setter.

whats a decent free C++ ide?

>>57083254
vi

>>57083254
I remember KDevelop had pretty nice code completion features.

>>57083328
Thanks. Just started CS so I only needed something that I could compile quickly when working at home.

>>57083254
ed

Can I become decent at python in a years time? I'm studying medicine aswell.

>>57083254
Emacs

Python is shit

>inb4 stating the obvious

>>57083391
Python is a powerful and easy tool, so it'll be possible to get proficient in it, but as a first language it is not good.

>>57079959

>best scripting language?

Ruby > Python / Perl > Lua >> Bash >>>>>>> VBA


>ones that can be run on most systems without having to install extra stuff is a plus

Well, depends on the OS:

iOS comes with Ruby
Most Linux distros comes with Python
Win comes with VBA (...eeew...)

>>57083411
>lying on the internet

>>57083481
Thank God I didn't do that

>>57083493
>>57083493
>lying before G*d

>>57083422
>as a first language it is not good.

Why not? I've heard the opposite

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>>57083508
>G*d
>*
that explains why you're trying to sell snake oil

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>>57083467
>Ruby
>better than anything

>>57083411

>Python is shit

Oh, you better tell Google, YouTube, Yahoo, the National Weather Service, the NSA, the NASA, Dropbox, Second life..

And don't use Linux, Blender, Dropbox..


I still think Ruby is better, but Python is already a top-tier language.

>>57083540

>t. CS freshmen

>>57083553
>Yahoo
>The National Weather Service
>Second Life

Wow, you've really convinced me

>>57083570
You're right, there's no use for Ruby in CS.

I heard that javashit is actually similar to Scheme.

is it a meme, or true?

can I fire up a REPL and wrap stuff in closures?

how would I express ((lambda (x y) (* x y) 5 10) for instance?

Why is MATLAB syntax so shit?

>>57083599

((x, y) => x * y)(5, 10)

>>57083599
it's a meme.

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>>57083585

>let's just ignore the fact that ruby was created by a guy working at university at the research lab on programming languages and compilers

>>57083725
What does that have to do with anything?

>>57083737

1. Ruby comes from a scientific background.
2. At my university we had a Ruby course.
3. Your opinion is Float::MIN. Get off this board.

>>57083774
t. NaN

>>57083779

Well played, anon.

why does /dpt/ despise OOP so much? i'm actually curious

>>57083833
it's shit

>>57080289
that's not programming

go on biz or adv

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to whoever suggested http://www.buildyourownlisp.com/

fuck you

this doesn't teach you anything useful about C or Lisp. It just has you use some autist's piece of shit library to parse expressions in a manner that looks like lisp

>>57083774
>Ruby comes from a scientific background.
So does Python. That doesn't mean anything.
>At my university we had a Ruby course.
What is even your point here?

>>57083411
i thought so too until i learned how beautiful and comfy python is

>>57083875
i want to hear some reasons why that is

only python and C should exist

>>57081570
I took your suggestions and reimplemented my-reduce and my-map. I hope this is what you meant by tail recursive, I'm still pretty new to alot of these concepts and FP in general.

http://pastebin.com/YY5mEuA8

>>57083954
>only shit languages should exist
spoken like a true autist

>>57083945
Inheritance and inheritance-based encapsulation and useless in most cases but OOP languages force you to use them for everything.

>>57083998
*are useless

>>57083998
>t. brainlet

>>57084007
t. Pajeet

>>57083998
That applies only to Java.

>>57084024
You have no idea what OOP is, do you?

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>what do you program daily
this, for fun

>>57084029
t. Pajeet

>>57084031
I'm so sorry

>>57084031
im in this moment trying to figure out something similar to make for fun

what's THE BEST laptop for programming, laddyboys

>>57084061
any

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>>57083945

>>57083926

>So does Python. That doesn't mean anything.

So what?

Both Ruby and Python are great langauges.


>>57084031

Just ignore them.

People who only wrote a few hundreds line of code won't get the reasoning behind OOP.

>>57084075
Emilia knows what's up.

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>>57084082

>>57084074
If I have to type for hours on end I prefer a nice keyboard.
Also a matte screen for minimal glare. And a respectable battery life.

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>>57083945
.

>>57084095

>quick, post a bait pic
>that'll teach 'em

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>>57083998
Inheritance isn't bad in and of itself, it's classical inheritance that can easily lead to complex, brittle architectures that fall to pieces as requirements change.

Prototypical inheritance and concatenative inheritance do a much better job at achieving the true goals of inheritance by making it easy to combine classes in predictable ways.

Overall, even in languages that don't take this approach, you can get close with composition and interfaces.

But yeah, in practice OO tends to completely miss the mark.

Daily tip: coding isn't the same as programming

javscript != programming

>>57084082
Ruby is shit, though.

>>57084140
Next you'll tell me that texting isn't the same as writing.

>>57084140
no shit

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>>57084144
I think JavaScript == programming, but JavaScript !== programming

>>57083967
show your code or gtfo

>>57084163
>programming jokes
Ugh

>>57084168

helloWorldMessage :: String
helloWorldMessage = "hello world"

main :: IO ()
main = do
  putStr helloWorldMessage
  putStr "\n"

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>>57084175
Why do assembly programmers always feel like they're drowning?


Because they're programming below C level

>>57084184

putStrLn

>>57083528
Dynamic typization and whitespaces as procedural brackets.
The first doesn't give a sense what are you doing, and if you mistyped a name somewhere, good luck finding out what's the problem.
The latter was just my headache to figure out where spaces were typed or tabs.

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>>57084205

>>57084184
in C that code is shorter and faster to execute

All I know how to do is <html>

I'm not in college

How long will it take me to become, eh, reasonably adept at comp sci

Using readily available online resources.

It's time for a change, thx

>>57084160
umad, codemonkey?
>but muh agile

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>>57084200

>>57084228
>reasonably adept at comp sci
3 years

>>57084216
#define msg "Hello World"

main = putStrLn msg

>>57084239
>{-# LANGUAGE CPP #-}

>>57083998
but how else are you supposed to create complex structures to represent mundane things like vehicles or departments?

>>57084249
>not having that flag enabled by default

>>57083954
>python
agreed

>c
disagreed

>>57084263
>using ancient technology in a modern language

>>57084273
>CPP
>ancient technology

>>57084109
what are you trying to tell me with this? are you implying it's too complicated for you?

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>>57084285
>C language preprocessor, i.e. a shitty """"macro"""" language
>not ancient

>>57084228
become NEET or become pajeet

>>57084291
>shitty

t. simpleton

>>57084306
Prove me wrong.
Protip: You can't.

>>57084306
but preprocessor sure sucks

>>57084314
my digits prove you wrong

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>>57084323
Go ahead.

>>57084333
oh snap

you got btfo into orbit son>>57084323

>>57084333
delete this post

>>57084333
o sht

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>>57084333
PRAISE KEK

>>57084132
>Prototypical inheritance and concatenative inheritance
What langugaes do this?

Isn't prototypical inheritance a dynamic typing thing? How do either of these make combining classes more predictable?

>>57084333
OH SHIT
the cat makes it even better

bump limit
new thread
>>57084400
>>57084400

>>57084261
>mundane things like vehicles
Found the non-mechanic.