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Search - "o log n"
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Biggest scaling challenge?
The imaginary scaling issues from clients.
Client : How do you cope with data that's a billion times bigger than our current data set? Can you handle that? How much longer will it take to access some data then?
I could then give a speech about optimizing internal data structures and access algorithms that work with O(log n) complexity, but that wouldn't help, non-tech people will not understand that.
And telling someone, the system will be outdated and hopefully been replaced when that amount of data is reached, would be misinterpreted as "Our system can not handle it".
So the usual answer is: "No problem, our algorithms are optimized so they can handle any amount of data"6 -
(Interview for sde-3 position)
(continuation of https://devrant.com/rants/2132431/... )
Interviewer - *opens laptop. Gives a question.* solve this.
Me - *a bit surprised that such questions were being asked on a sde-3 level*
this is the 4th or 5th question from geeksforgeeks, isn't it? I know the answer to this. Do u still want me to solve it?
Interviewer - *not believing me* Yes
Me - okay. Well this *writing down the original solution mentioned on the site* is the verbatim code mentioned on the website, with complexity O(n^2).
However I feel this is not the optimal solution. Let me write a better solution.
*I provide a better solution*
This has a complexity of O(n log n) . What do you think?
Interviewer - Nope. This could be a lot better.
Me - okay. Let me see. Did some minor changes, added some caching (obviously this will have no effect on the base algorithm) etc
How about now?
Interviewer - nope. Still not good.
Me - okay. Can you tell me how to improve it?
Interviewer - no we are not allowed to solve problems for you. It is not our interview, it is yours.
Me - that makes no sense. Interviews are a two way street. I'd very much like to know the optimal answer to this.
Interviewer - okay
*copies down the answer from geeksforgeeks*
This is good
Me - *at first I thought this was a prank or something. *
I just mentioned this answer here.
Then I spent the next 10 minutes providing a BETTER solution.
May I know how yours is better?
Interviewer - this solution has 2-3 loops. Yours has a function calling itself.
Me - that's called divide and conquer using recursion mf!
Anyways let's take an example and do a dry run.
Interviewer - okay
*we do dry run*
Interviewer - oh yes. Yours ran faster. But it will run fast only sometimes.
Me - yes. Each time the algorithm rolls a dice to decide if it should run fast or slow. You have one goddamn awesome weed dealer man.
I got to go. Thank you for meeting me.14 -
@netikras since when does proprietary mean bad?
Lemme tell you 3 stories.
CISCO AnyConnect:
- come in to the office
- use internal resources (company newsletter, jira, etc.)
- connect to client's VPN using Cisco AnyConnect
- lose access to my company resources, because AnyConnect overwrites routing table (rather normal for VPN clients)
- issue a route command updating routing table so you could reach confluence page in the intranet
- route command executes successfully, `route -n` shows nothing has changed
- google this whole WTF case
- Cisco AnyConnect constantly overwrites OS routing table to ENFORCE you to use VPN settings and nothing else.
Sooo basically if you want to check your company's email, you have to disconnect from client's VPN, check email and reconnect again. Neat!
Can be easily resolved by using opensource VPN client -- openconnect
CISCO AnyConnect:
- get a server in your company
- connect it to client's VPN and keep the VPN running for data sync. VPN has to be UP at all times
- network glitch [uh-oh]
- VPN is no longer working, AnyConnect still believes everything is peachy. No reconnect attempts.
- service is unable to sync data w/ client's systems. Data gets outdated and eventually corrupted
OpenConnect (OSS alternative to AnyConnect) detects all network glitches, reports them to the log and attempts reconnect immediatelly. Subsequent reconnect attempts getting triggered with longer delays to not to spam network.
SYMANTEC VIP (alleged 2FA?):
- client's portal requires Sym VIP otp code to log in
- open up a browser in your laptop
- navigate to the portal
- enter your credentials
- click on a Sym VIP icon in the systray
- write down the shown otp number
- log in
umm... in what fucking way is that a secure 2FA? Everything is IN the same fucking device, a single click away.
Can be easily solved by opensource alternatives to Sym VIP app: they make HTTP calls to Symantec to register a new token and return you the whole totp url. You can convert that url to a qr code and scan it w/ your phone (e.g. Google's Authenticator). Now you have a true 2FA.
Proprietary is not always bad. There are good propr sw too. But the ones that are core to your BAU and are doing shit -- well these ARE bad. and w/o an oppurtunity to workaround/fix it yourself.13 -
Not as much of a rant as a share of my exasperation you might breathe a bit more heavily out your nose at.
My work has dealt out new laptops to devs. Such shiny, very wow. They're also famously easy to use.
.
.
.
My arse.
.
.
.
I got the laptop, transferred the necessary files and settings over, then got to work. Delivered ticket i, delivered ticket j, delivered the tests (tests first *cough*) then delivered Mr Bullet to Mr Foot.
Day 4 of using the temporary passwords support gave me I thought it was time to get with department policy and change my myriad passwords to a single one. Maybe it's not as secure but oh hell, would having a single sign-on have saved me from this.
I went for my new machine's password first because why not? It's the one I'll use the most, and I definitely won't forget it. I didn't. (I didn't.) I plopped in my memorable password, including special characters, caps, and numbers, again (carefully typed) in the second password field, then nearly confirmed. Curiosity, you bastard.
There's a key icon by the password field and I still had milk teeth left to chew any and all new features with.
Naturally I click on it. I'm greeted by a window showing me a password generating tool. So many features, options for choosing length, character types, and tons of others but thinking back on it, I only remember those two. I had a cheeky peek at the different passwords generated by it, including playing with the length slider. My curiosity sated, I closed that window and confirmed that my password was in.
You probably know where this is going. I say probably to give room for those of you like me who certifiably. did. not.
Time to test my new password.
*Smacks the power button to log off*
Time to put it in (ooer)
*Smacks in the password*
I N C O R R E C T L O G I N D E T A I L S.
Whoops, typo probably.
Do it again.
I N C O R R E C T L O G I N D E T A I L S.
No u.
Try again.
I N C O R R E C T L O G I N D E T A I L S.
Try my previous password.
Well, SUCCESS... but actually, no.
Tried the previous previous password.
T O O M A N Y A T T E M P T S
Ahh fuck, I can't believe I've done this, but going to support is for pussies. I'll put this by the rest of the fire, I can work on my old laptop.
Day starts getting late, gotta go swimming soonish. Should probably solve the problem. Cue a whole 40 minutes trying my 15 or so different passwords and their permutations because oh heck I hope it's one of them.
I talk to a colleague because by now the "days since last incident" counter has been reset.
"Hello there Ryan, would you kindly go on a voyage with me that I may retrace my steps and perhaps discover the source of this mystery?"
"A man chooses, a slave obeys. I choose... lmao ye sure m8, but I'm driving"
We went straight for the password generator, then the length slider, because who doesn't love sliding a slidey boi. Soon as we moved it my upside down frown turned back around. Down in the 'new password' and the 'confirm new password' IT WAS FUCKING AUTOCOMPLETING. The slidey boi was changing the number of asterisks in both bars as we moved it. Mystery solved, password generator arrested, shit's still fucked.
Bite the bullet, call support.
"Hi, I need my password resetting. I dun goofed"
*details tech support needs*
*It can be sorted but the tech is ages away*
Gotta be punctual for swimming, got two whole lengths to do and a sauna to sit in.
"I'm off soon, can it happen tomorrow?"
"Yeah no problem someone will be down in the morning."
Next day. Friday. 3 hours later, still no contact. Go to support room myself.
The guy really tries, goes through everything he can, gets informed that he needs a code from Derek. Where's Derek? Ah shet. He's on holiday.
There goes my weekend (looong weekend, bank holiday plus day flexi-time) where I could have shown off to my girlfriend the quality at which this laptop can play all our favourite animé, and probably get remind by her that my personal laptop has an i2350u with integrated graphics.
TODAY. (Part is unrelated, but still, ugh.)
Go to work. Ten minutes away realise I forgot my door pass.
Bollocks.
Go get a temporary pass (of shame).
Go to clock in. My fob was with my REAL pass.
What the wank.
Get to my desk, nobody notices my shame. I'm thirsty. I'll have the bottle from my drawer. But wait, what's this? No key that usually lives with my pass? Can't even unlock it?
No thanks.
Support might be able to cheer me up. Support is now for manly men too.
*Knock knock*
"Me again"
"Yeah give it here, I've got the code"
He fixes it, I reset my pass, sensibly change my other passwords.
Or I would, if the internet would work.
It connects, but no traffic? Ryan from earlier helps, we solve it after a while.
My passwords are now sorted, machine is okay, crisis resolved.
*THE END*
If you skipped the whole thing and were expecting a tl;dr, you just lost the game.
Otherwise, I absolve you of having lost the game.
Exactly at the char limit9 -
There is a mAtHeMaTicAl pRoOf 🤡 that a comparison-based sorting algorithm cannot get more efficient than O(n*log n). That's bullshit. Radix sort et al. — granted, they're not comparison-based.
But there is one comparison-based algorithm that can sort an array in O(n). It's called Stalin sort.
It traverses the array and deletes every item that doesn't appear in order. Boom, problem solved — the array is sorted in O(n), at the expense of losing (most of the) elements.
This is the perfect metaphor of Stalin's politics.4 -
I don't like vector math for gamedev. It's not that it's hard. Vector math isn't hard until operations become O(n log n). It's that it's unintuitive, slow to write, and when I finally come to a solution after arduous number crunching, it always looks obvious, boring and kind of ugly. I don't think I could ever write a piece of vector math that I could be proud of.2
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Sometimes Im pretty impressed and envious by the skills of my fellow students.
Usually it looks like this:
me: So Uhm what u got for the <insert class here>?
him/her: Well its pretty simple algorithm which has big O of (Log(n)/1000000) which also mines bitcoin in the meanwhile and yeah, last night I figured out that it now generates electricity...
me: Uhm... My program prints Hello world... But backwards...
Like for real, sometimes I wish I find the motivation, to be awake 2 days straight just bursting with ideas of some crazy shit. Right now Im like 'You see that star behind that cloud? Jup it shines too bright, gotta get some sleep' -> Browsing devrant...2