/dpt/ - Daily Programming Thread

Rust is for brainlets who are scared of pointers

Java is the best language

>>60928673
Java 8 was a mistake

>>60928662
Rust have pointers too, you can even use them in safe code.

C# is the only sane choice for enterprise or decent applications with time constraints

Gawd damn. Whoever thought it'd be a good idea to mix types with OOP

C++ is literally the abortion child of C and Python. Two very good languages independently. But combined is cancer.

What is a good book for learning python?

>>60928630
Welcome to /programminglanguagewarsgeneral/

>>60928694
>C++ is literally the abortion child of C and Python.
What the fuck?

What possible reason would I have for using => arrow functions in javascript instead of function()?

>>60928694
>Whoever thought it'd be a good idea to mix types with OOP
What the fuck are you talking about? The whole point of OOP is to have types.

>>60928738
One liner lambdas.

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>>60928706
There are not none. Learn Ruby instead

>>60928694
why though? there's plenty of top quality sepples code about that's very fast and neat

all depends on the programmer. shit ones are going to churn out shit code regardless of the language

I'm working on an application to another company cause fuck refactoring the entire code base with no other employees ((((because there are no other employees)))).

I guess I'm also working on a jenni clone in Go, but I'm becoming tired of that and want to do something else.

>>60928694
>mixed C and python
Eh. I don't see it at all. It's OOP+C+random garbage a committee decided on+random garbage a committee decided on to fix the old garbage they added+random....
lim->inf
Random garbage.

a lot of people come to these threads asking
>how do i into coding
but how do i into self motivating?

>>60928806
>but how do i into self motivating?
Watch all these brainlets constantly shitting on glorious languages such as C++ and realize you will never have such a worthless existence. Now go be awesome.

>>60928754
>What the fuck are you talking about? The whole point of OOP is to have types.
No, it's not you stupid idiot.
In true fashion OOP programming. There exists only one type. The object. And with that single type, polymorphic inheritance can be done to create derived objects. But they're still of the type "object".

>>60928780
See the above. Types in OOP languages is fucking stupid

>>60928694
u r dum

>>60928806
>Diet
>Exercise
You'd be surprised how much these things get you to do shit

>>60928806
powdered caffience snorted straight up the snout la

or just pick a theoretically challenging problem and develop a solution for it

>>60928806
Find a project you feel driven to do. Don't learn only for learnings sake. Make something. Try to apply what you've learned realistically and throw it away if you don't like it.
Most languages have orthogonal features and a lot of redundant features figuring out what set of features you want is important and can't be done by inspection.

>>60928630
/dpt/ - Designated Pajeet Thread

>>60928806
You don't. You just set a certain time of your day to programming and mesh your hands on your keyboard until progress is made.

>>60928829
i do both, to some degree
i cut fast food and soda completely, don't smoke cigarettes. i also skate a lot.
the problem is I'm more motivated to get better at skating (which doesn't help my career) than I am to sit down and code as much as a few lines.

>>60928820
Exactly, you have hierarchies of types.

>>60928820
think you're being a bit myopic there
ok sepples isn't "true fashion OOP" but I don't see why that's a bad thing. even java isn't "true fashion OOP" since it doesn't have first class fucntions.

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>he needS static typing

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>>60928857
>skating programmer
God. I can't help but imagining you're the girl in this picture.

>>60928886
Who says that OOP implies first class functions?

>>60928875
They're still all the same type, idiot.
A int and a std::string are not.

>>60928886
You try using OOP in a well suited manner in C++.
Python is the closest anyone would ever get to true OOP. And C++ and Python are so fucking different

>>60928886
>it isn't a bad thing
Anon it severely compromises the paradigm.
OOP can be optimized as well as functional programming if effort was put into it. It just isn't being done because people like to avoid it.
I don't hate real oop, it has a niche use. But pseudo-oop is terrible. The compromise completely ruins the goals of the paradigm.
It's like if you used mutable globally shared state everywhere in FP and still called it FP.

>>60928907
because any object must have a procedural interface?

>>60928890
Is it a new meme?

>>60928926
>python is the closest
Try smalltalk or a real pure OOP language.

>>60928662
Rust has pointers, too, though

Are variable-length arrays in C legit?
That is, are they good practice? Sloppy practice? I had never used them until this year and it still throws me off working from a paradigm of ``C can't do that''.

>>60928939
I don't follow.

>>60928926
>Python is the closest anyone would ever get to true OOP.
python doesn't even have proper encapsulation with is the fundamental principle of an object. you are ridiculous.

>>60928890
I don't need it. But it's clearly better.
It's painful to have had it for years and now work in lua and python for two weeks.

>>60928960
and no pointer arithmetic, they're practically useless.
I can't even use a negative number as an index.

>>60928961
>Are variable-length arrays in C legit?

This is one of those arguments that never ends, so you aren't going to get a straight answer.

>>60928926
>They're still all the same type, idiot.
No, they're subtypes of the same type. They implicitly convert to other types. That doesn't mean they're the same type any more than being able to write

void foo(double);
foo(1);

means that int and double are the same tye.

>>60928961
it depends on the specific case in which you're using them. there are many case where variable lengh arrays are good practive.

also you've probably seen them used in your very first C hello world program (printf uses them)

first for Swift is best language

>>60929043
You missed the bus anon

>>60929043
and the last

any good python curses programs i can mess with to learn from?

>>60928961
They are a poor substitute for std::vector.

>>60929107
no, because it's 2017
use django and build a JS curses emulator instead

>>60929109
VLAs are not the same as malloc arrays moron

>>60929016
I'm not sure I follow.
Is that related to how argv/argc get set?

>>60929109
wrong and irrelevant

>>60929154
no, printf is defined using VLAs

int printf(const char *format, ...);

>>60929107
Use Termbox instead.

>>60929180

That's not what a VLA is.

>>60928996
Try this then

std::vector<float> foo(std::vector<float>);
foo(1);

You can't? Oh. Maybe because C++ sucks and Python is awesome.

The issue I'm having is that with true objects, you can create actual true lists that contains different types of data.
With C++, this is near to impossible. And even if you did manage to do it, the only way to actually access the values is as such

for(Object obj:objects)
{
    type objType = objects.getType();
    switch (objType)
    {
        case typeInt:
            intObject value = static_cast<intObject>(obj).getValue();
    }
}

And then the case is repeated for every single type you want to support.
>this is "Proper" c++ code

>>60929294

data HL xs where
    Null :: HL '[]
    (:>) :: x -> HL xs -> HL (x ': xs)
infixr 5 :>

>>60928963
Wrong, it's actually message passing.

>>60929336
Speak in a language that people actually use

>>60929294
>Complaining because you can't put an int where you expect a list of floats
What's your point? Do you just hate type checking or something?

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>>60928973
> <*const T>::offset(-1)

Why such low quality bait? Rust has many issues, but pointer arithmetic and manipulation aren't some of them.

do you have to understand the whole program before you can make open source contributions?

>>60929352
>lel use python xD

Speak in a language that ADULTS actually use

>>60929371
Did you read the rest of the comment?

That's what it's like with OOP in a typed language

>>60928706
inventwithpython(.com) was* pretty good

* = unfortunately, you'll only learn python 2.

>>60929378
You should understand the entire translation unit you're modifying, at the very least.

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>>60929391
You mean like Python?

>>60929399
> python2
> Literally encoding retarded

In the trash it goes.

anyone know how to delete a file with bash after a php script is done using it? it doesnt let the php file finish the file im using before bash deletes it

>>60928662
c is for brainlets who are scared of registers

>>60929454
sh -c "rm $file"

>>60929454
you could just delete it with php
then you wouldn't have to worry about scheduling between them

>>60929393

std::variant bruh

>>60929391
https://news.ycombinator.com/item?id=1803815

>>60928894
>rollerblading
>not inline skating

>>60929490

for(Object obj:objects)
{
    type objType = objects.getType();
    switch (objType)
    {
        case typeInt:
            int value = obj.getVarient().get<int>()
    }
}
Congratulations. You changed one line of code into something else.

>>60929378
Ideally yes. Whole-system understanding is invaluable but rarely obtained.

>>60929488

when i tried this it said resource unavailable. I'm using "unlink()"

>>60929294
You're making the C++ way more complicated than it needs to be.
It's literally just this.

unsigned char* objects;

To access an object of type T preceded by other objects whose combined width is i:

*(T*)(objects + i)

>>60929294
If you have to do that then you are not using good OOP practice.

>>60929294

>The issue I'm having is that with true objects, you can create actual true lists that contains different types of data.
What can you do with with a list of data whose types you don't know anything about?

>>60929584
Did you close the file stream first?

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Do anyone working here uses oop for their projects? If so, then what are you doing and why do you use oop?

>>60929661
what is OOP?

>>60929661
Nope.

I do love lain though

>>60929637

thank you based

PHP is given too much hate

>>60929628
In situations where the types can switched between with ease. For example, std::vector, std::tuple, and std::list. Or long int, int, float, double, etc:.

Common operations that can be done on multiple types should be able to combined into a list.

>>60929706

>In situations where the types can switched between with ease.
In these situations there is a common interface to those types, so you can just upcast to the interface and use that. lrn2 inheritance.

>>60929706
The benefit is not worth the cost.
Types are compile time constructs. To make type information available at runtime, like slow-ass languages like Python do, would be too great a sacrifice for the rather limited and petty use cases your suggestion would facilitate.

>>60929706
To add to >>60929739, in the cases where there is no common base class, you can also do this:
>make an abstract base class to represent the interface you need
>make a template class that extends it and stores an instance of its parameter
>in practice, have the parameter be the type you want to be treated uniformly with other types
>have your template class implement the abstract base class's virtual functions in terms of the parameter type (use specializations if necessary)
>store a list of instances of the abstract base class
>put template class instances in it

i made an ALL CAPS IRC NETWORK

ircs://2hu-ch.org/lobby

>>60929795
BUT WHY

>>60929817
I THINK SO!

>>60929793
no idea wtf you're talking about overcomplicating this shit

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>mfw sepples doesn't even let you specialize only some parts of a template class
>mfw literally why even include template classes if you ain't gonna do that shit

How do I write a program worth using? Meaning that at least I'll use it regularly, if not anyone else. Everything I do and need to do is already written, and better than I ever could (meaning there's no lack of features or bugs that make me want to write from scratch or contribute).

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How do I stop "<" from turning into "&lt" when I pass my C# string to an xml document? Escaping the character like "\<" doesn't work and neither does @"<".
Help me /g/

>>60929875
the solution is to git gud enough at programming that solving a problem from scratch feels less intimidating than learning to use and trust whatever solution is already out there

>>60929615
how the fuck does it feel that no one fell for your shitty bait you stupid sepplesfag

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>>60928694
>python
>good
Brainlet fagineer detected. Probably got laughed out of /sci/.

>>60929875

The problem of assessing consumer needs and conceiving of a product to meet those needs is more suited to a marketer than a software engineer or computer scientist. We can't tell you how to think up a good product concept. We can tell you how to make a good product once you know what it is that you'll be making and what features it should make.

What are some good practical uses for block ciphers or just permutations/substitutions in general? I've just started getting the hang of basic crypto maths and encryption and I want to practice implementing it somehow in a program

>>60929294
The reason python can do this is the exact same reason it's slow - it isn't compiled to native code.

If you need to do that in you're code you wrote there you need to refactor. I can't even think of a function that performs some computation on either a list of floats or an integer and still have the same internal logic. It definitely doesn't even work in python: if you write a function that appends something to a list passed in as an argument:

def foo(list):
  list.append(1)

if you do

foo(1)

you will get an error anyways since ints don't have an .append() function. How to get around this? oh the exact same reason you propose by using type information and then performing whatever the fuck you're trying to do there.

And if there are cases where the same program logic can apply to different types, you can use templates or inherit a virtual class.

>>60929869
sepplesfags cannot justify this
btfo

>>60929927
You can't have < as text in an XML document, you have to escape it as &lt; or have it in a CDATA section

<![CDATA[<This is fine>]]>

>>60928630
Why are you faggots into traps? It's gay as fuck.

>>60929869
what did he mean by this?

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I am making an hours tracker in php/mysql, dumbed down for chad and stacy.

God damn I don't miss starting projects from scratch. I really like working in a developed framework with error catching and conventions established.

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>>60930041

I'm writing an app for Android with minSDK (API 10).

And I need a replacement for this method:

View.setOnSystemUiVisibilityChangeListener

and also:

View.OnSystemUiVisibilityChangeListener()

Any help,..please

>>60930012

>it isn't compiled to native code
IIRC, there are implementations that will at least JIT it to native code. But regardless, the semantics of the language make efficient code generation impossible. The expression x + y necessitates a function call, because there is no guarantee that x and y are both integers or both floats, or in some way capable of being added with hardware instructions. And since a function call involves at minimum two stack operations, it will take at bare minimum 4-5 times slower than just running the add instruction, and that's assuming that no registers have to the saved and restored, not even the base pointer.

>>60930053
In pathetic-ass sepples, say you have a class like this:

template <typename T> class array {

(Assume it has a reasonable constructor, destructor, copy constructor, copy assignment operator, and equality operator.)
Then later, you can't even do this shit.

template <> class array<char> {
public:
   // extra constructor
   array(char const* str) {
      /* not even gonna bother writing this but basically
         it would copy the string into the array object's
         buffer and stop at the null character; we need an
         explicit specialization to add this constructor
         because for most other types, an array can't
         reasonably be null-terminated */
   }
/* I would like to put a keyword here to say
   that in addition to whatever I put in this class
   definition, this class should have everything
   that would be there if it weren't an explicit
   specialization. However, in pathetic-ass sepples,
   there is no way to indicate this! It simply cannot
   happen at all. :^) */
};

>inb4 "put all the unspecialized functionality in a base class"
Fuck no, that's stupid. I mean yes it would work but you shouldn't have to do that, it's ugly and doesn't accurately reflect your intention.

Does /dpt/ like 21:9 monitors?

>>60930195
tbf it's dumb to specialise shit in this fashion anyway

Java is solid. Java Lift...not so much.

>>60928738
Making your code look as disgusting and unreadable as possible

>>60929934
How will getting better at programming make it more viable to write from scratch something that took hundreds if not thousands of man-hours to program? I'm not going to write from scratch, say, mpv, just because I can. Similarly, why waste time rewriting the simply but necessary programs, like say coreutils, that you may already use daily?
>>60929985
I'm not necessarily talking about something I could sell, I meant more so a utility or feature-rich program. For example, I have written some bash scripts I use regularly, but those are specific to my needs, and thus not packageable and reusable in any form, and they're also so trivial that they're hardly worth mentioning. But when if comes to needs outside those of scripting, there already exist great FOSS solutions - everything's been done already. It feels like there's no room for originality, only room to attach yourself to an existing project and contribute.

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>>60930212
>yfw damage controlling this hard

>>60930269
i'm not
C++ is shit

>>60930195

Why would you even want to specialize that?
That's not an array any more, it's a null-terminated string. You're breaking the common semantics. Retardation like this is what brought us the vector<bool>.

>>60928662
I've done my fair share of pointer fiddlin' my boy. Time to let the alpha language take it's spotlight tho.

>>60930195

template<typename T>
class array
{
    ...
    array(typename std::enable_if<std::is_same<T, char>::value, const char *>::type str)
    {
        ...
    }
    ...
};

>>60928816

I can about stand C++ but it certainly is anything but glorious and very flawed, anything beforte C++11 is a disaster and even C++14 is a mandatory choice over C++11 because C++11 misses out obvious shit like std::make_unique.

If you think C++ is glorious then you must literally have no experience with any other language. They all suck, some suck less than others, certainly C++ doesn't come out on top.

(And I'm definitely not advocating for rust, that's another shitpile entirely.)

>>60930311

>std::enable_if
What is this? Literally just a "refuse to compile this if the templates are bad"

>>60930302
>his language doesn't support vectors of booleans

>>60930263
>implying writing something like mpv is a time waste
it's a huge working experience, for starters

secondly, you never know what you may find out down the road. maybe mpv lacks certain features, maybe your implementation is better, maybe you pivot to something completely different and new, etc. I don't think it's possible to plan ahead in these cases and disregard everything with "time waste". Let corps plan ahead and calculate risks, you are free to improvise and have fun

and the most important part -- impress cs cuties by your own media player

>>60930302
>Why would you even want to specialize that?
Because a null-terminated string is fundamentally a specialization of an array, and it can be useful to treat it as such.
>That's not an array any more, it's a null-terminated string. You're breaking the common semantics. Retardation like this is what brought us the vector<bool>.
See above.

>>60930189
I was thinking of going into detail of how python interpreters are essentially state machines or virtual machines written in languages that compile to native code but someone who claims to love python would already know that so I just kept it simple.

At the same time that anon hates C++ yet the libraries that make python shine - numpy, scipy, opencv, etc - are written in C++, not in python so it makes me think that they don't really understand their favourite language.

>>60930263
1) for fun
2) there are concepts and ideas that have yet to be programmed

There are also libraries that exist on one platform or not the other that you can create. You can implement APIs or protocols. There's so much you can do. If you base your creativity on stuff that's already been made obviously you won't be able to think of something new.

And even then you can just have fun doing something that's already been made, like a ray tracer or a TCP client-server chat.

>Learned C#
>No idea on what to do with my newly acquired knowledge

I'm between Unity, ASP.NET and Xamarin for Android

>>60930361
begin using a toilet

>>60930263
>only room to attach yourself to an existing project and contribute.
It's a good path, a lot of people come up with original ideas after years of supporting and contributing to other projects

>>60930361
Write fizzbuzz in the most unreadable way in C# right now

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I'd like to create a production scheduling program for scheduling tasks to machines or other resources.

The program would first get the number of resources or machines from the user.

Then the user could entry the tasks and finally the sequence of how the tasks should be performed (e.g. Task1 & Task2 must be finished before Task3 can be started).

Do you think this would be too challenging for a beginner? Any ideas on how to continue with this?

>>60930356

>Because a null-terminated string is fundamentally a specialization of an array, and it can be useful to treat it as such.
But it's not. It doesn't work like an array of char does. You're allowed '\0' in an array of char, but not in a cstring. You're breaking the semantics and breaking the expectations of client code - just like vector<bool>.
Template specializations are almost invariably a bad idea.

>>60929927
if you're trying to insert a new element, use the proper methods:
https://msdn.microsoft.com/en-us/library/system.xml.xmlnode(v=vs.110).aspx#Anchor_3

If you want < as text then you want it to become &lt;. When you read it back from the XML file to a string, &lt; will be decoded to < again.

>>60929661
I am right now.

When you are working within established GUI frameworks to make programs for normies to use, you're gonna use OOP. That's just how it works, homie.

>>60930361
Make a web browser

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>>60930387
>>60930387
so you want to remake MS Project?

but no you should do it if it interests you. you won't finish but you might learn some shit.

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>>60930361
>Learned a language before needing to learn it to do something useful

>>60930399
The class that I have in mind -- that I wrote once a long time ago, but have long since abandoned in favor of pure C, which makes everything so much clearer, cleaner and more simple -- wouldn't even disallow storing '\0' in an array<char>. You could have been like

array<char> my_char_array("hello world");
std::cout << my_char_array.size() << std::endl;
// => 13
my_char_array[5] = '\0';
std::cout << my_char_array << std::endl;
// => hello
std::cout << my_char_array[6] << std::endl;
// => w
// it still exists in the array!
// this is just a plain array
// the constructor only works the way it does because if you're using a string literal, it would be stupid to have to pass in a string literal's size with the string literal

/dpt/ if white supremacists have their "14 words" signs, should our protest slogan be "13 letters?"
>hello world

I'm reading MIT-Scheme manual.
What is meant by 1024-word block?
If I'm using 64-bit, this would be 1024 * 64 bits?

>>60930524
>forgetting the exclamation mark

>>60930524
>>>/trash/

>>60930387
>>60930446
Gantt charts aren't magic. Writing a shitty project management tool to practice is wasting everyone's time.

Honestly, you should probably spend more time reading code and API documentation than writing code in YOOL 2017.

It would be better if you picked one of these and figured out how to fix bugs and add features than if you reinvented the wheel.

https://github.com/opf/openproject

http://www.libreplan.org/open-source/source-code/

https://sourceforge.net/projects/projectlibre/

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hey fag/g/ots, I'm doing Hackerrank challenges to learn some shit (pretty much a newb here). I'm doing pic related, and my code passes the first 3 test cases but fails on the 4th. We can't see the test cases so I have no idea what exactly it's doing, can't really debug it. Pic related are the instructions, can you help me think of weird scenarios given the instructions? Don't really wanna post my code.

Link here
>https://www.hackerrank.com/contests/w33/challenges/twin-arrays/problem

>>60930544
More like comma.
>hello, world

>>60930581
Absolutely disgusting, never post this again.

>>60930048
you're mistaken. not liking traps is gay as fuck

>>60930500

>Complains about C++ templates not being powerful to make generics un-generic
>Promotes C which has zero generic capabilities beyond void*

>>60930562
the naive way is to calculate all valid combinations and choose the minimum. the question's harder than it first seemed to me. if you come up with a less than O(n^2) solution let me know what it is

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It's alive boys!
Now I need to put some I/O in there.

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do you write your projects piecemeal in tiny steps checking each one to ensure it works or do you code the bulk of a project then fire it off and fix what's broken?

>>60930562
>Don't really wanna post my code.
don't really want to do your challenge for you so you can act like you did it yourself

>>60930680
yeah, I'm going the naive way, but it's still failing some test cases, and I have no idea why. Is there any way to see the test cases? What are some weird test cases I should watch out for?

My solution is just two for loops, appending the sum to an array IF the indexes are not the same, then getting lowest number from the array.

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>>60930645

>>60930707
that's why I'm not posting the code, so no one will rewrite it for me. I'm not looking for an answer, just some tips on what I might not be seeing in the instructions.

>>60930722
>but it's still failing some test cases, and I have no idea why.
if it's not timing out, then your code has an error in it. enumerating all valid possibilities and choosing the minimum is mathematically impossible to give an incorrect answer

>>60930768
right, so how do I know if it's timing out? Does it say so somewhere? All I can see is "Test Case 3 Failed"

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>>60930688
excellent

>>60930785
do an infinite loop and see what the timeout message looks like

>>60930680
wait why wouldn't you
>find the minimum in each array
>check if index is the same
>check the next index in each for the lower value
>sum appropriate value (lowest + lowest or lowest + lowest of the next lowest)

I mean am I reading something wrong or are you guys really doing several sums?

>>60930562
no solution?
A[1,2,3]
B[1,2,3]

multiple positions?
A[2,2,2,2,2,2,2,2,2,1]
B[3,3,3,3,3,3,3,3,2]

I mean without at least explaining your logic/code how can we guess what you're missing?

>>60930830
nope, it's not timing out. fuck it, I'll post the code. Not looking for a solution, just someone to point out where I'm fucking up since I can't find it.

 def twinArrays(ar1, ar2):
    dictx = {}
    for i in range(n):
        dictx.update({ar1[i]:i})

    dicty = {}
    for i in range(n):
        dicty.update({ar2[i]:i})

    mm = []
    for key in dictx:
        for key2 in dicty:
            if dictx[key] != dicty[key2]:
                mm.append(key + key2)

    return sorted(mm)[0

this is my solution to this >>60930562

>>60930890
>check the next index in each for the lower value
by which I meant
>check the next lowest in each
>compare for the lower value of the two alternate index positions

>>60930890
that still results in n^2 time in the worst case

>>60930890
>no solution?
>A[1,2,3]
>B[1,2,3]
solution here is 3
>>60930890
>multiple positions?
>A[2,2,2,2,2,2,2,2,2,1]
>B[3,3,3,3,3,3,3,3,2]
solution here is 4

you don't have to return the values added nor their indexes, just the lowest possible sum.

>>60930918
>dictx[key] != dicty[key2]
this can fail when either dictionary has duplicate elements. this solution is super complicated too, you don't need to use dicts at all. you just need 2 nested for loops

>>60930954
then
A[1,1,1,1]
B[1,1,1,1]
solution would be 2. hmm, how about

A[1]
B[1]
since 2nd constraint is 1<= array elements

>>60930645
>generics
They're not generics, they're templates. C++ doesn't have generics.
>Promotes C which has zero generic capabilities beyond void*
That's all you need. In plain C, a type is pretty much just a compile-time name for a size. If all you're dealing with is a size why glorify it with a name.

>>60930942
>>60930890
this was halfway my original idea, but then i got a bit confused about if the lowest for each array were the same index and how you'd progress from there. the answer is to shimmy your way up by trying the next highest for array 1 + current for array 2, and then the opposite, and advance after that. the optimal solution has to be in the tail of both lists if none of those succeed, which is the inductive step i was missing

>>60930995
>a type is pretty much just a compile-time name for a size
Factually wrong.

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/dpt/ how do I bidirectional associative container?
specs:
>let c be the container
>c[a] = b should be equivalent to c[b] = a
>if c[a] == b then c[b] == a
>constant time insertion, deletion, and lookup
Is it possible without just maintaining two hashmaps and keeping them converse to one another? That seems like cheating.

>create new file in the solution view in visual shit
>isnt actually created in the filesystem
it's like it was made by the mentally retarded

>>60931100
also interested

>>60931101
>it's like it was made by the mentally retarded
made by the mentally retarded what

>>60931100
>>60931115
(Set (UInt, UInt), [a], [b])

>>60931124
the

>>60931148
>made by the mentally retarded the
How intelligent is a mentally retarded the?

>>60931165
are you retarded? the as the ones that are mentally retarded.

>>60931177
Ssh, you're ruining the joke.

>>60931101
>>60931124
>>60931148
>>60931165
>>60931177
>>>/trash/

>>60931177
Clearly he is the mentally retarded.

>>60928806
DRUGS

>>60931195
>Clearly he is the mentally retarded.
The mentally retarded what?

 def twinArrays(ar1, ar2):
    if len(ar1) == 1:
        return 0
    else:
        mm = []
        for i in ar1:
            for j in ar2:
                if ar1.index(i) != ar2.index(j):
                    mm.append(i + j)
        return sorted(mm)[0] 

So now it's timing out on one test case, passing others. Wtf am I doing wrong?

>>60931302
Using Python.

>>60931436
embarassing

>>60931302

def myfun(ar1, ar2):
tups1 = []
tups2 = []
for i in range(len(ar1)): tups1.append((i, ar1[i]))
for i in range(len(ar2)): tups2.append((i, ar2[i]))

tups1.sort(key = lambda x: x[1])
tups2.sort(key = lambda x: x[1])

for i in range(len(tups1)):
  if tups1[i][0] != tups2[i][0]: return tups1[i][1] + tups2[i][1]
  if tups1[i+1][0] != tups2[i][0]:
    m = tups1[i+1][1] + tups2[i][1]
  if tups1[i][0] != tups2[i+1][0]: return min(m, tups1[i][1] + tups2[i+1][1])

>>60931507
>>60931302
btw this implements what i said here >>60931025 if you want an explanation in words of the algorithm. it should be O(n log n)

>>60931555
>>60931507
actually i'm an idiot it'd be

def myfun(ar1, ar2):
tups1 = []
tups2 = []
for i in range(len(ar1)): tups1.append((i, ar1[i]))
for i in range(len(ar2)): tups2.append((i, ar2[i]))

tups1.sort(key = lambda x: x[1])
tups2.sort(key = lambda x: x[1])

i = 0

if tups1[i][0] != tups2[i][0]: return tups1[i][1] + tups2[i][1]
if tups1[i+1][0] != tups2[i][0]:
  m = tups1[i+1][1] + tups2[i][1]
if tups1[i][0] != tups2[i+1][0]: return min(m, tups1[i][1] + tups2[i+1][1]

because if the minimum of ar1 has the same index as the minimum of ar2, then neither can have the same index as any other element (obviously). overthunk that one a bit

Does any one have one of those programming challenge lists?

I'm trying to read some more H2DP and it's not making sense today

the point is I'm trying, right?

>>60931302
What the absolute fuck...

def twinArrays(ar1,ar2):
    return min(ar1) + min(ar2)

>>60931700
0-1: Solve P vs NP
2-3: Strong AI
4-5: Machine translator with 99.999% accuracy
6-7: GNU Hurd
8-9: Unbreakable cryptosystem other than OTP

Dubs: You cannot use a computer or any electronic device to complete this task
Trips: You cannot look to or use any prior research (everything must be original work)
Quads: You must complete the entirety of the task blindfolded
Quints: If you require a program to solve your task, you must write it in Malbolge

>>60931868
roll

>>60931868
roll
if i get gnu hurd i'll kms

>>60931593
>>60931555
>>60931507
actually i'm a double idiot because you don't need to sort the arrays, just do a single pass keeping track of the min and the 2nd from min so it's O(n)

>>60931868
>>60931900
Done. But the solution doesn't fit in this comment box.

>>60931948
good job fag
bet u can't do this in O(1)

>>60931948
Well no fucking shit. That's what I wrote here >>60931832

>>60931981
no, what you wrote was
>What the absolute fuck...
>

def twinArrays(ar1,ar2):
    return min(ar1) + min(ar2)

>>60931981
what if they are the same index u fag

>>60931999

def foo(ar1,ar2):
    min_ar1 = min(ar1,range(len(ar1)))
    del ar2[min_ar1[1]]
    return min_ar1[0] + min(ar2)

>>60931964
how would that work anon, if the complexity is at least proportional to the length of the param array?

>>60932099
wait

def foo(ar1,ar2):
    min_ar1 = min(zip(r1,range(len(ar1))))
    del ar2[min_ar1[1]]
    return min_ar1[0] + min(ar2)

>>60928630
>tfw you will never see her gnu deb swirl :'c

IS A CUTE! A CUTE!

>>60932114
do it all in compile time

is iterating through the same list twice still O(n) ?

>>60932217
its O(2n) which translates to O(n) so yeah

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>>60931100

c = Table[{j,i},{i,1,N},{j,1,N}];
c = Flatten[c];

>>60931981
you're not very bright either apparently

>>60932217
No
Iterating through it once -> O(1 * n)
Iterating through it twice -> O(2 * n)

>>60932217

foreach(var i : list)
{};
foreach(var i : list)
{};

O(n)

foreach(var i : list)
    foreach(var j : list)
    {};

O(n^2)

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>>60928630
I don't get this picture... can someone explain?

File: x φ.jpg (38KB, 480x480px) Image search: [Google]

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>>60932248

>>60932126
that's not correct at all. you can't just have a solution that works sometimes, or most times

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>>60932248

>>60932217
yes, but you don 't have to iterate through a list twice to find the 2 smallest values
>>60932241
completely wrong

>>60932258
Okay, so it's a trap.

>>60932237
What a fatty

>>60932248
hiro is cute

>>60932272
Was does a gnu have to do with a dick though, that's what I didn't understand. When I saw >>60932258 I understood that they just replaced the flower with the Debian logo and the elephant with the gnu.

>>60931981
>>60932099
>>60932126
you should probably read the problem before trying to solve it, or calling other peoples solutions dumb..

>>60932295
Just trapfags forcing their shit everywhere they go

>>60932322
gays*

>>60932337
>Results provide clear evidence that GAMP men are not homosexual
https://www.ncbi.nlm.nih.gov/m/pubmed/26498424/

>>60932354
>gays making up studies to pretend they're not gay

>>60932354
>men with sexual interest in transgender women
What if I self insert as the trap?

>>60932354
>They also indicate that GAMP men are especially likely to eroticize the idea of being a woman.
>literally eroticize the idea of being fucked as a woman by a man
F A G S
A
G
S

>>60932378
Sorry, where is your citation? I can't see it

>>60932404
>women being fucked by men is homosexual
Yeah sven, not nearly as hetero as you thinking of men getting fucked by men

>>60932406
>I can't see it
that's because only heteros can see it, sorry bub

why does everyone think ops image is a trap?

i figured she just has a hairy moose-knuckle

>>60928662
Rust has pointers you ignorant mongrel

>>60932419
A guy getting off to the idea of being a woman getting fucked by a guyis gay

>programming

>>60932431
>getting horny thinking about fucking my wife
>this makes me gay

>>60932480
>being this illiterate

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>>60932431
also you're right
we should stop discussing this immediately
you shouldn't have brought this up


does anyone have any ideas for an awful programming language?

>>60932495
>does anyone have any ideas for an awful programming language?
Java + Rust

>>60932513
>Java + Rust
You mean C++?

>>60932517
I had no idea C++ had a borrow checker.
C20 came early i see

>>60932495
>does anyone have any ideas for an awful programming language?
C++

>>60932495
Yes it's called C++

>>60932529
std::unique_ptr and std::shared_ptr

>>60932495
>does anyone have any ideas for an awful programming language?
Haskell with Rust syntax.

>>60932549
auto pointers are hardly the same.

>>60932556
>auto_ptr
Not C++

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Does anyone know what's going on here?
The book seems to be fucked up or not written for the newest version of racket

>>60932583
i meant c++20 in case that was unclear you pedantic autist.

the last time I was here was a year ago

and you're still thinking that C++ le ebin lowlevel abstractions are worth arguing over

I'll come back next year

>>60932587
nevermind, I forgot to include the right library

>>60931868
If hurd I'm fucked

>>60928662
>C programmers actually believe this.
The pure retardation of C pajeets when confronted by Rust always impresses me, and I don't even like Rust.

>>60932621
Oh, easy stuff

>>60932593
auto_ptr's will almost certainly not be in C++20, which isn't yet formalised

>>60932636
>The pure retardation of C pajeets when confronted by anything not c*

>>60932636
C is designed for simple minds that like to live in a bubble

>>60928694
>Believes C is Good
>Believes C++ is the Child of Python, a language made nearly ten years after it which is nothing like it.
You must have been dropped on your head as a child.

I've heard Rust shares some of the functional programming ideas with Erlang (claimed by many Rust users). How true is it?

>>60929399
It's not that hard to learn Python3 after learning Python2. You've just got to spend about 10 minutes learning what was changed. Print is a function, UTF-8 doesn't into retarded, etc.

>>60928738
Confusing pajeets who don't know what they do and keeping IE users from being able to use your website.

business idea: A non-GC'd functional language that can go as low as C

>>60928890
I don't need it. I do it automatically because I'm a good programmer. Sometimes people need it when editing my code because they don't do it automatically and end up writing buggy trash.

>>60928759
ruby is a terrible language
use perl cunts

>>60932686
Don't know erlang but I've seen some elixir for private mmo servers and it's nothing alike. The overall feeling is close to ML

File: [Anime-Koi] Sabagebu! OVA SPECIAL MISSION 3 [BD][h264-720p][022E6A92].mkv_snapshot_07.43_[2015.07.04_16.14.00].jpg (430KB, 1276x1432px) Image search: [Google]

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>>60932710
>tries to make a language that combines the best attributes of higher and lower languages
>end up with a language with shit performance and shit development instead
What did [literally everyone who's tried this] mean by this?

>>60932710
Rust is the most functional out of C/C++/Ada/Fortran

>>60932750
literally what language
>>60932767
and rust is also a bad language.

>>60932750
If you have your HOFs in text expansion macros, you will add no function call overheads

>>60929661
wrote minor python game where I used OOP. basically, had a player class which had specific players as descendants and an obstacle class with specific obstacles as descendants. the OOP did save a good amount of code/time.

OOP is not inherently bad, it's just used inappropriately by incompetent college grads who had it shoved down their trachea.

>>60932781
>and rust is also a bad language.
Most certainly better than C++/Ada and fortran

>>60932767
>Rust is the most functional out of C/C++/Ada/Fortran
C++17 is more

>>60932781
>literally what language
Matlab.

>>60932808
Sure, by C++77 we will get modules in boost::modules and tears in std::unicorn that will be implemented in compilers by 2089!

>>60929378
No. The whole point of functions are to avoid needing to understand the entire system. Only bad code requires understanding all of it to make contributions to it. You think Torvalds actually memorizes all of his kernel and thinks about it as he writes more code? Any reasonably large project is impossible to completely grasp at once. You have to abstract away the majority of it.

>>60932797
i can literally do anything in D, 3x easier than in Rust. And D's actually good GC makes GC a non-issue.
>>60932810
Theres nothing more general and open source out there?
Time to make one then.

>>60932840
>i can literally do anything in D, 3x easier than in Rust
Same here, stop blindly hating on Rust. Same goes for the other Rust fag
>And D's actually good GC
No it isn't, D's GC is an implementation of stop-the-world style GC.
Sociomantic is working on porting their GC to D from D1 which runs on a different thread. Until that Rust always has an upper hand in runtime

>>60929661
I usually just use pure functions, but when using other people's libraries, which is quite often if you want portable software, I have to use OOP. It's just how the world works.

>>60930441
This. OOP was shoved down my throat while using QT.

I don't know what's really wrong with OOP, I'd use Classes over Structs because it's more sophisticated. Although the usage may vary in languages

File: d.png (9KB, 120x91px) Image search: [Google]

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>>60932840
Tell me about D, I'm interested. I learned C++ as a first language and really didn't like the unnecessary complexity of it, which was made even worse after I learned Python and Haskell. The problem with those two is that while they're both very expressive, neither is particularly high-performance. Is D considerably more expressive than C++? Gimme a quick rundown.

>>60932767
>>60932808
C is better

>>60932895
>unnecessary complexity of it
[citation needed]

>>60932915
Post legs

>>60932905
here's your fucking citation, straight from the horse's mouth, cunt

http://harmful.cat-v.org/software/c++/I_did_it_for_you_all

>>60932895

D is an alternative to Java or C#, not to C++.
Until GC is optional - and really optional, not "exclude yourself from the standard library and all 5 other libraries" optional - D will never be an alternative to C++.

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>>60932915
O-ok

>>60932895
https://dlang.org/
Check it out, the website should give you an impression

Then check out D for C++ developers

>>60932904
Not everyone is rewriting Linux, Cnile

>>60932869
>an implementation of stop-the-world style GC
No it isnt.
>blindly hating on rust
ive spent a decent amount of time on the docs and playbox going through the basics. 9/10 times Rusts version is longer and more tedious.
>>60932895
> Is D considerably more expressive than C++?
Absolutely with UFCS alone.
Modules are a dream as well, and i imagine C++'s wont be much of anything compared.
D in general is what C++ should be, everything is just simpler and more sane.

>>60932921
>cat-v

>>60932894
If your languages does not treat classes and structs the same way it's garbage.

>>60929927
>>60930093
You probably don't want to stop it from doing that or you'll generate invalid XML, you dumb C# newfag. There are functions built into your XML Document object that allow you to add new elements, if you're trying to do that instead. Give a code example so we know why you're being stupid.

>>60932943
No, Classes are called by referrence, Structs are called by values by default. It's a sane approach

>>60932942
>content hosted on cat-v that has nothing to do with cat-v and was produced totally independently of cat-v

>>60932895
I can guarantee you no matter the language you pick, it's not what's holding you down.

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>>60932710
a functional language implementation without a gc is unthinkable since everything must be an expression.

>>60932895
>Menu offers to let you customize your pizza or just buy a set one from the menu
WHAT THE FUCK, WHY IS THIS SO NEEDLESSLY COMPLICATED?! FUCK THIS PLACE, IM OUTTA HERE.

>>60932926
FAT

>>60932966
You can't have RAII?
I heard it undermines TCO but I don't know how true it is

>>60932767
fortran has pure functions. does rust have them too?

>>60932953

It's insane and backwards. Reference semantics should coincide with reference syntax. I should not have to refer back to the definition to determine whether

foo = bar;
foo.mutate();

Will cause bar to mutate.

>>60932978
>autistic meltdown

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>>60932980
>>60932277
DELET

>>60932966
>>60932983
You can absolutely have RAII, better you can even treat sequences as expression by considering they evaluate as the last expression.

>>60932999
Lose weight first

>>60932995
>Will cause bar to mutate.
Use structs then?

Also you can also use
bar = foo,dup
foo,mutate();

>>60933025

>Missing the point this hard

>>60933025
Hello fellow dvorakian

>>60933036
I just gave you 2 workarounds

>>60933048

You failed to understand the criticism at all.

>>60933054
I didn't see that as a criticism, it's just a lack of knowledge I saw

>>60933054
no u

>>60933038
?

>>60932710
So actually not functional at all since you're demanding side effects?

>>60932993
This.
>>60932767
Does Rust have pure functions?

>>60933123
>since you're demanding side effects?
no im not.

>>60933123
>Does Rust have pure functions?
Yes of course

>>60932241
O(2 * n) = O(n)
>>60931100
Just use one hashmap and keep it converse to itself.

>>60932999
Never, fat pigs should all die

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I want to learn C#

How do I get started?

>>60933132
Low level == Side effects. That's how memory and IO work.

>>60932354
>replacing the L with a G for GNU in the term "LAMP stack"
No, they're definitely gay.

>>60933201
thats why its a business idea
gonna change the game.

>>60933188
>what kinda are these people sitting couch is this its not even made of geobaskets fucking plebs
>what kinda are these people sitting couch is this
>what
>kinda
>are
>these
>people
>sitting
>couch
>is
>this
fucking what

Make a generic function that reverses assosiative arrays and returns them

[
"a": [1,3],
"b": [2]
"c:" [2,3]
]

Should give you

[
1: ["a"]
2: ["b","c"]
3: ["c"]
]

The function should work with int, float, double and strings

>>60933235
whats with this same question.
its been posted here like three days in a row.

>>60933235

in what language?

>>60933249
Your language

>>60933235
Why wouldn't "a" be in 3 as well?

>>60933262
>>60933235
Yes, my bad

NEW THREAD

>>60933273
>>60933273

>>60933271
fag

I'm trying out go and it's such a fucking meme language. Instead of declaring variables with

int i = 1

it's

var i int = 1

What the fuck is wrong with them? They're literally just doing this to be different instead of for an actual logical reason.

Arrays are declared

classifications := [3]string{"Hello", "Meme", "Language"} 

Honestly why can't they just use C style syntax, if they did then it could actually be a good language instead of a meme language.

>>60933222
Nobody is going to pay for a meme, so it's not a business idea.

is there a way to order a select a query based on how many conditions are met? i have an array[][] of integers and i would like to test an input with the content, if its between X and Y so i would like to somehow rank the output according to how many block of integer from the array it satisfies. i was reading the psql documentation on documentation and it said this

>Tip: If your needs go beyond the capabilities of these conditional expressions, you might want to consider writing a stored procedure in a more expressive programming language.

is it saying i should use a programming language to progressively query into the database rather than write a single query for all

>>60928848
That is some pretty worthless advice. Be a dear and keep your inane tips to yourself.

Not how I'm the first person to even acknowledge this statement of yours. Idiot...

>>60928662
C is for brainlets who are scared of higher levels of abstraction.

Thankfully I am scared of neither and use both.

>>60933284
You can go var i = 1 and it will automatically assume it's an integer. If you go var i = 1.0 it will automatically assume it's a double. var i int = 1 means you will try to parse the said input to integer. Go is heavily influenced by C# and I can see they did not have the balls to str8 up copy the amazing syntax C# has.

The reason why vars are used is to save time (as in writing, just imagine the joy of writing var instead of 5 nested collections and it has zero impact on performance) and to save you from remembering a lot of shit when working with some libraries like regex. When you are working with massive frameworks some of the inbuilt shit requires weird as fuck declarations which no sane person can remember however you can just write var and it will work right.

It has it has it's downsides too (for example until recently when you foreached regex matches you had to write Match instead of var in C# otherwise it would assume you are trying to do something else, but it's currently the standard in high quality web development.

>>60928694
You have no fucking idea what you're talking about, retard.
C++ is NOTHING like Python.

>>60933882
>replying to C faggots that study in pajeet land
the mad man

>>60933697
you can do that in less than 30 characters in C# with LINQ and lists

>>60928890
I don't need it, I want it, because it's good.
Dynamic typing is fundamentally an error.

>>60928890
Now imagine working with 20 other people 8 hours a day, Good luck debugging.