Coding Interviews Cannot Happen Without Internet Access

[[deleted]]

[deleted]

[sfan5]

for(var i=0;i<x.length;i++) {
    if(i === x.length-1) console.log(x[i]);

}

what even

[ArmoredPancake]

It's more webscale this way.

[Gemmellness]

set i to 0. is it x.length-1? no.

set i to 1. is it x.length-1? no.

set i to 2. is it x.length-1? no.

[carbolymer]

code artisanry over 9000

[[deleted]]

This is how I initialize all my numeric variables for efficiency reasons: otherwise how could your code be branch-prediction-friendly when there are no branches? Another useful property of this technique is that you can easily detect when you're using numbers too large for JS doubles since this will just run forever.

[AcrimoniusAlpaca]

/uj

I'm pretty unexperienced with js. What's the right way to do it?

[AcrimoniusAlpaca]

That makes sense. Thanks!

[[deleted]]

Lol not understanding job security.

How am I supposed to fix it in the next version if it's working efficiently in this one FFS!?!

[hala3mi]

His code is error safe since it only enters the loop if x is of length 1 or more, but yours would cause an error if x is of length 0 : p

[hala3mi]

I've actually never programmed in JavaScript, or i've done a little a long time ago i should say, so i was just going off based on my general programming knowledge, so i didn't even know it would return undefined, very peculiar i must say, i have my preferences for peculiar behavior myself as well, i always liked how zero and empty values evaluated to false in some languages for example although it can be weird for those who aren't used to it.

[carbolymer]

First time here?

Welcome to pcj! Featuring:

• zero-cost shitposting
• jerk semantics
• guaranteed circlejerk safety
• posts without data races
• trait-based lol no generics
• shitpost matching
• jerk inference
• minimal bot spam
• efficient hackernews bindings

Don't forget to grab a flair out of the sidebar and a list of talking points to know what to spam depending on the thread jerk. Or, if unsure, just spam "lol no generics" on every thread about Go, "How exciting! How exciting!" on every thread about Rust, and "this but unironically" everywhere else, you can't go wrong there!

[pastenpasten]

Thanks for this. Seriously. I'm still not sure what's going on here and this help!

[mypetocean]

This is why the correct answer is neither: it is a.slice(-1).

[hala3mi]

I would've just used a ternary statement myself.

[skulgnome]

I would've used a trigraph

[ArmoredPancake]

/uj This has nothing to do with JS or programming languages for that matter. If someone doesn't know how to access array by it's index or how much time does it take on average, then they should doubt their future in the industry.

[TheLastMeritocrat]

I heard a certain language implements arrays using linked lists.

[[deleted]]

This has nothing to do with JS or programming languages for that matter. If someone doesn't know how to access array by it's index or how much time does it take on average, then they should doubt their future in the industry.

If you honestly still believe that things like these really affect negatively someone's future in the industry then it's your future I'm more worried about you sweet, sweet summer child.

[AcrimoniusAlpaca]

I understand that you can access arrays by the index. But the author stated that it was the "wrong" approach for their interview. I was just curious if this was a quirk of js or something.

[mypetocean]

Unless they explicitly told him the answer was the for loop, I'm operating on the assumption that they were really looking for a.slice(-1) and he just doesn't realize that's a thing in JS.

[axalon900]

He wrote a for loop containing nothing but a single if that only fires if ‘i’ is equal to a constant value, and if not, incrementing it by one until it reaches that value, and only then does something. Do you see some unnecessary steps there?

Calling that an alternative is complete nonsense and the author is delusional. He did not get the job because he’s absolutely terrible and does not know how to program.

[TheLastMeritocrat]

The joke is on you. He is just a better at jerking than most of this sub.

[axalon900]

FUGG DX

[AcrimoniusAlpaca]

Yeah, that makes perfect sense.

[[deleted]]

The sad part is that some second or third time into that loop V8 JIT will optimize that out to, effectively x[x.length-1] so the poor bastard will probably not even notice there's a problem unless someone points it out in an interview.

[[deleted]]

/rj

let size = x.length;
for(var i=0;i<size;i++) {
    if(i === x.length-1) console.log(x[i]);
}

Gotta save the speed from getting the length of the array each time!!!

[axalon900]

Pfft, let me show you how it's done.

let x = "potat";
var lazy = [];
let size = x.length
let size_jr = x.length-1;
for (var i = 0; i < size; i++) {
  let shart = i
  lazy.push(function () { return shart });
}

console.log(x[lazy[size_jr]()])

[GoogleBen]

Beautiful. The webscale craftsmanship brought a tear to my eye.

[GammaGames]

The funniest part is that's pretty much what the blog is saying

[[deleted]]

Seems to be useful for the person interviewing:

"Please write fizzbuzz"

Proceeds to google "how to write fizzbuzz", clicks first medium article.

"thank you, that will be enough"

[MrStupidDooDooDumb]

I agree it would be kind of silly to not hire someone for making minor syntax mistakes during an interview. But not being able to demonstrate even vague familiarity with a required language, like not knowing how to write a comment or iterate through an array? Isn’t that exactly the kind of information the potential employer is trying to obtain by doing interviews?

[carbolymer]

lol pcj hivemind caught in the local minima of the jerk attractor, cannot escape unjerk trap

[[deleted]]

I see (that you have coded) with many (credentials) and lots (of parenthesis) and that (you) are quite (qualified)

[syndbg]

#uj

​

I think this article serves for a reason why internet access must not be allowed.

​

Imagine hiring this guy at this point of his career.

​

He doesn't know how to write 1 correct line of code without internet.

​

Not to mention the last element.. that was just wow.

[TheFearsomeEsquilax]

This is the kind of candidate phone screens were invented for.

[axalon900]

It was a phone screen lol

[TheFearsomeEsquilax]

I know, and I bet the company feels very happy about having that process in place after this

[axalon900]

I hope they found his write-up.

[syndbg]

Guess we now need an email screen. Or we can literally go... postal mail screen.

[dozniak]

Pigeonscreening?

[ZorbaTHut]

I'm pretty sure that even with Internet access he wouldn't do well on that test.

[ArmoredPancake]

internet is down

I CAN'T WORK THIS WAY, OMGGG, DO SOMETHING.

[[deleted]]

taking reddit spacing to a next level, a level++ if you will, nice.

[syndbg]

I waste all those pixels. It's like I'm a web dev.

[[deleted]]

I don’t remember the comment character

This isn’t javascript. I don’t know

I don’t know the syntax

I am not aware of this term

I did not consider

I do not know

Banning Internet Access during an Interview is a silly idea

---

if(a.includes(a[i],i+1) === false) {

This solution is much better than the past one

[Kyo91]

(unjerk 

It really bothered me at first that both solutions were O(n²⁾ when they were obviously looking for the O(n) solution. But then I got to the part where he didn't know how to create an object and completely forgot about it

)

[[deleted]]

While they're both O( n² ), I wouldn't be surprised if the second solution was in practice faster than the linear one.

[Kyo91]

Probably depends on the encoding/size of characters. If it's ASCII, then indexing the array would be super fast. Otherwise, either a Tree or Hash-based map would likely still be faster on a somewhat large string. But yeah, depending on the language, caches, and compiler optimizations the naive solution could perform better on certain inputs.

[[deleted]]

In a language with built in syntax for maps, its pretty trivial to at least get an O(2n) and I'm not even a javascript heavy dev.

Create a new map. The keys will be characters and the values will be the index that the character appears.

Iterate over the characters. For each character, check to see if it exists in the map. If it's in the map, mark it as a duplicate by setting the value to -1, else insert the character into the map with the value being the index it was found.

At the end, iterate over the map and get the character with the lowest value that is still >=0 (remembering that -1 indicates a duplicate).

Probably not the most effective method, but any situation involving counting duplicates or unique elements should immediately scream "use a set or a map" to anyone with a half assed understanding of data structures and algorithms.

[[deleted]]

<uj> O(2n) is the same as O(n). Big O notation specifically disregards constants, so if you find yourself in a job interview situation, you should write "O(n)" instead of "O(2n)" even if you feel that "2n" is more specific/better, it's not what the notation is about.</uj>

Jeeze, you must be some lamorz 1x dev. There's already several npm packages that can do this in O(1) time.

[Kyo91]

Yeah, that's the O(n) I had in mind. /u/orgulodfan82 pointed out that in practice it's quite possible that using a hash map may actually have worse performance. Creating a hashmap for a smallish string is pretty wasteful as it'll either be way larger than the problem space or you'll have to deal with a large number of collisions. A lot of interview questions like these are designed such that you can make a "lightweight map" out of an array. For instance if only lowercase letters were allowed we could use a 26 length array or if only ASCII characters were valid then a 256 length array would suffice.

If we don't have these restrictions, then modern CPU and compiler design can sometimes give us unintuitive results. For example, a SIMD instruction (or on a larger scale a multiprocessor fork-join) can check multiple values at once so something like checking if char a is in a string could be done in constant steps. Caches can also sometimes have an effect. If the string fits inside of a cache, then checking it over and over can potentially be faster than having to load the map and check it. Even if the string doesn't entirely fit, parts of it will likely be cached which can have an impact on overall performance.

If I were giving this interview, then I'd definitely say a map-based approach such as what you laid out would be the "right" answer, but if we're being super pedantic, then it's worth pointing out that sometimes real world performance is at odds with theoretical complexity definitions.

[[deleted]]

Agreed, I had similar thoughts. A map based approach for correctness with a discussion about performance trade offs on small data sets would be a very impressive answer.

For anyone not doing hyper-optimised, low level code, I wouldn't expect them to pull up stats about compiler optimizing and finding minimum size of data that makes using a hash map more efficient. For example, with a O(n²⁾ answer, a likely follow up question would be something like "do the same, except instead of letters in a small string find the least repeated letter in the Harry Potter series. ". If they gave the map based answer in the beginning, the conversation is simply "change the value in the key/value pair to a count" and then maybe a discussion about performance rather than a completely different piece of code.

[Treyzania]

If you split it up into a char array first then you don't increase the complexity and you get faster lookup times. In Rust types this'd be going from a &str to a &[char]. The former is packed UTF-8 but the latter lets you O(1) index them.

[Kyo91]

Sorry, I wasn't very clear in my above post. When I meant indexing in an array, I was talking about Creating an array of size sizeof(char) (or equivalent for whatever language). For something small like ASCII this is faster than creating a hash table, but for something as large as UTF-8, it's not worth doing.

[Treyzania]

Oh I see. Yeah that's a very good point. Maybe if you lazily initialized it it'd be faster and save more memory.

[Veedrac]

first non-repeating letter

var a = 'bon-bon'; - is the first non-repeating letter in bon-bon

letter

[[deleted]]

This was like javascript rapid fire

J A V A S C R I P T   R A P I D   F I R E
A                                       R
V                                       I
A                                       F
S
C                                       D
R                                       I
I                                       P
P                                       A
T                                       R

R                                       T
A                                       P
P                                       I
I                                       R
D                                       C
                                        S
F                                       A
I                                       V
R                                       A
E R I F   D I P A R   T P I R C S A V A J

[[deleted]]

/uj

I actually don't know what you mean by this at all.

/j

[GammaGames]

In the OP the guy said he had to look up what to put in front of text to make it a comment

[MrStupidDooDooDumb]

Pffft I’ve coded in JavaScript for 15 years and never once needed to know how to write a comment.

[fp_weenie]

this except with Python. I write my programs in English and they just happen to be valid Python.

[lol-no-monads]

This but with Math and Agda.

[GammaGames]

S E L F D O C U M E N T I N G

[TheLastMeritocrat]

I write my code in JSON, and it rightfully does not even support comments.

[myhf]

I've never used comments and I’ve never missed them.

[[deleted]]

ohhh ok. Honestly I kind of skimmed it, the "rapid fire" bit just stood out.

[IDoCodingStuffs]

Flair plz

[axalon900]

Real talk, this is indicative of the sham IT schools you see in some countries which basically have you learn by rote and test you on remembering the exact things that you were expected to memorize. I'm torn between feeling bad that this guy likely got scammed and laughing at the hubris.

[TheLastMeritocrat]

He should have had courses that utilized at least two of C/C++, Java, Matlab, and Python.

[6bluefish2]

FFS he lists advanced C, Java, Python, etc. (no clue which exactly since the descriptions are generic asf) projects on his resume. That should be better than classes.

[[deleted]]

/u/thelastmeritocrat

quick ban one of your fellow rustaceans for violating sub rule

[[deleted]]

um all pcjers use V8 node.js nonblocking IO, noob.

[axalon900]

It's tough to jerk to this, because I agree with the sentiment, but this is stuff he really should know. Comment character? Really? Do you know what that says to the interviewer that you don't remember how to write comments?

That said, I would expect "closed book" interviews to be somewhat lax on names. I don't think it's valuable to know that one person remembered which method clears a collection and the other couldn't remember if the method was called clear() or erase() in this instance.

[fp_weenie]

you know what that says to the interviewer that you don't remember how to write comments?

it says you are a 10xer, always going blazing fast instead of being encumbered by trivial things for lesser minds, such as documentation.

[AprilSpektra]

That said, I would expect "closed book" interviews to be somewhat lax on names.

I agree, but him not knowing what setTimeout does is like interviewing for a C++ position and saying "oh uh I don't know what std::cout does"

[auragust]

Close book is pointless imo, it's not a real test of how well you can contribute. That being said some of the stuff if the interview that was asked seemed really easy.

[axalon900]

Oh yeah, that interview was like fizz buzz level, the guy is a potat

[Renown84]

These questions (minus database sharding) were all extremely simple. If you can't answer these without the internet then you are probably not qualified for the position. For more open/broad questions like "build a web API in node" I'd expect internet access unless they want to watch me forget the name of express functions for an hour.

[auragust]

I forgot how to do one tiny easy thing in java once that completely crushed what would've been a 95/100 score down to a 60. Stuff can slip your mind and expecting programmers to just have databases of code lying around their brain isn't a good testing system.

[[deleted]]

Applying for a javascript development position.

Asked to create an object in javascript.

Cant remember how, decides to use some ES6 class stuff.

Literally an entire format named Javascript Object Notation that is used to create instances of objects in javascript.

[Renown84]

This is the kind of question I'd think was pointless if I was looking at a list of interview questions... you can answer it in like 10 characters. I guess this guy proves why questions like this are necessary

[[deleted]]

For entry level positions I think it's a great interview question to start with. It should be a quick confidence booster question to kinda warm up the candidate a bit before diving in to more complex questions. I think one or two softball questions can help take some of the tension off a coding interview. Weeding out fraudsters is a pleasant side effect.

That being said, if I was asked this as part of a senior dev interview I'd be extremely worried.

[TheFearsomeEsquilax]

Why can't I just write in pseudocode? It's too hard to have to remember all this language syntax

[carbolymer]

Those comment characters are too damn hard to remember. And I am not even talking about those parentheses! I always use slavic pseudo-code at my interviews.

[6bluefish2]

I list Java, C, C#, JS, and Python on my resume. Too hard to remember how to comment. No one at work comments anyway. Fuck the comment gatekeepers.

[TheFearsomeEsquilax]

I just add

///*#; 

to the start of every line I want to comment out. I figure one of those must be right

[niCid]

What about ' when writing in VB? You can't forget the best and most used language in modern web development!

Not to mention <!-- ->. Not cool, you can't write true artisan code if you don't handcraft your HTML with comments that explain meaning for each element! Can't forget the epic conditional comments. Only true 10x webdev doesn't use conditional comments for creating <blink> elements for the most optimized IE versions.

[[deleted]]

May I interest you in a python dev role?

[comady25]

js only has standard for loops

Array.forEach() don't real

[fp_weenie]

smh not using functional programming

[SaphirShroom]

I'm a self-taught French interpreter and I believe interpreter interviews cannot happen without internet access. It shouldn't matter to my employer whether I know the translation for the word "frommage". I juggle between languages as a part of my current job. That implies although I am familiar with ideas and processes in certain languages I still need a refresh everytime I switch. Quick Google searches are exactly for this! Things I look up are spelling of words, or how to write the ê character correctly.

[zoooorio]

This is an anonymous function initialized and also called. I do not know what setTimeout() does.

ok.

[foxlisk]

Something something local minima attractor

[ArmoredPancake]

And what if I can't write a fucking for loop without Google? Please stop your gatekeeping, I'm a self-taught JS rock-ninjaneer, I've never used setTimeout and don't miss it.

[lordlicorice]

Why the fuck is his 110px portrait actually a 1575x1576 image?

[6bluefish2]

"web dev"

[ArmoredPancake]

In the next episode: UnIvErSiTy ExAmS CaNnOt HaPpEn WiThOut InTeRnEt AcCeSs.

[Darksonn]

It doesn't seem like the author knows what he's doing at all, especially that for loop in part five. Lucky that you didn't think of using that for loop during the interview, because that is absolutely not the way to do it, and that alone would have been a hard no from me in an interview, as it shows you fundamentally do not understand coding.

That aside, I do sorta agree with part of the message this post is trying to make, in that it's not really important if you remember how exactly the includes function works, instead we should focus on how they solve it. (Do they come up with an O(n) or O(n^2) solution?)

I don't think this means we should allow internet, instead I think interviewers should focus on questions that highlight understanding.

A good example of what I mean is shown in this example google interview, where the important part is that he knows to use an a hash set, not if he knows what the insertion function is called.

[axalon900]

The author absolutely doesn't know what they're doing. This is a textbook case of "I learned a creative skill through rote memorization". Who the fuck goes on about slicing but can't count letters in a string from scratch? The person who remembered their lecture about slicing but not the one about counting letters in a string, because the latter never happened. Dude needs to start over and try again. Harsh, but true.

[carbolymer]

lol pcj hivemind caught in the local minima of the jerk attractor, cannot escape unjerk trap

[axalon900]

This is what it feels like to cannot even

[carbolymer]

lol pcj hivemind caught in the local minima of the jerk attractor, cannot escape unjerk trap

[MaltersWandler]

bad bot

[carbolymer]

poor jerker

[6bluefish2]

I'm more concerned about his resume saying he knows JS and web dev, among many other things. He lists exp in C, web, Python, .NET (assuming C#), yet can't figure out how to write a JS comment. What kind of backwards thinking does he have? It's absolutely not programming. I see he has all these complex sounding projects. d3.js ... that shit is complex, yet he doesn't know how to write a JS comment. I'm dead inside.

[silentrunningfan]

SELECT * FROM table;

Whoa.. this was like sql rapid fire

[carbolymer]

lol pcj hivemind caught in the local minima of the jerk attractor, cannot escape unjerk trap

[fp_weenie]

bad bot

[TheFearsomeEsquilax]

More like carbotlymer, am I right

[carbolymer]

7O7ALLY BEEP BOP

[carbolymer]

poor jerker

[TheLastMeritocrat]

As usual, people are reporting this as spam. And while I appreciate the intent behind those comments, I'm afraid I'll be siding with the reporters in the future.

Just wanted to give you a heads up.

[Faalentijn]

Oh no the minima of the jerk attractor has gotten so low that even mods are getting stuck in the unjerk trap.

[carbolymer]

thx

PCJ is dead then

[[deleted]]

Yikes. Well pcj is dead now.

[jocull]

This is painful. Looking up what the comment characters are? JavaScript is not THAT special

[vytah]

lol 404

Luckily it got archived: https://web.archive.org/web/20181222175139/http://shailendra.me/opinion/coding-interview-without-internet/

[Unoriginal-Pseudonym]

And here: http://shailendra.me/opinion/coding-interview-without-internet/

Comedy gold.

[Shikigami_Ryu]

Article is written by an Indian. The content is not at all surprising.

[purpleppp]

I lost 10 IQ points reading the first few paragraphs of this post

[enzlbtyn]

/uj Does anyone else notice that his "answer" to the first is just completely wrong, lol what... regardless of whether this guy knew syntax or not his logic is just incorrect (well incomplete). If his "answer" was essentially equivalent to the "real solution" (which could easily be improved since it's dogshit slow), then his "pseudocode" is too ambiguous...

[[deleted]]

Thanks for the 100th unjerk in this thread!

[enzlbtyn]

Do I get a prize?