By Radewoosh, history, 15 months ago,

Can somebody tell me what's going on with Project Euler problems on HackerRank? Do they just steal the problems? Project Euler says that they ban everybody who spoils solutions to problems above 100, and it took me a few minutes to find a solution to one of the later problems with difficulty $80\%$.

I see a few options:

Maybe Project Euler doesn't know about it? -- Hackerrank isn't as quality as CF or PE, but still, I think that PE's admin would already hear about it, and it's big enough that it might look like a problem.

Maybe PE allows HR to take their problems? -- Of course, it's possible, but knowing the policy and rules of PE it looks very strange -- finding this code took was very easy, somebody just posted it in the comments section on HR.

Money? -- ???

Of course, everybody sometimes steals a problem, to use it in his/her school or university for example, but this looks like a huge process. Does anybody have any information? I'm just curious.

• +65

 » 15 months ago, # |   +36 It seems to me that they introduced the rule about problems 101+ just recently, about after problem 700, so I think they haven't thought about hackerrank yet
 » 15 months ago, # |   -72 grabs popcorn
 » 15 months ago, # |   +89 You just reminded me that HackerRank exists.
•  » » 15 months ago, # ^ |   +34 Yea, I've just got the same due to someone's blog and I've realized that some time ago it was a riddle for me.
 » 15 months ago, # |   +177 Project Euler once went down and people looked for an alternative place to hold problems (to save them). Hackerrank happily started converting them to their own format, it was a free source of quality problems for them, it was called ProjectEuler+.Project Euler went up after several months but Hackerrank continued converting problems because it wasn't forbidden.If anybody from Hackerrank reads this, you still owe me 200 EUR coupon for Booking.com (won in some competition).
•  » » 15 months ago, # ^ | ← Rev. 2 →   +95 Errichto on stream: "I don't want money".Errichto on CF: "HackerRank, you owe me 200 EUR".
•  » » » 15 months ago, # ^ |   +88 If you'd say that you don't want money, would it mean that you'll give yours to others...?
•  » » » » 15 months ago, # ^ |   +11 Haha, was just a joke. Although I don't understand why you say "give yours to others". From what I understood, they didn't give him the prize money/coupon right?Btw, my comment is in no way saying Errichto doesn't want the 200 EUR. If anyone from HackerRank reads this, please give Errichto the prize you promised.
•  » » 3 weeks ago, # ^ |   +14 I kind of solved around 300+ problems on project euler and yet didn't learn much. I would simply write a code that ran for few minutes sometimes half and hour to give correct answer. offcourse most of them were bruteforce . Until One day i saw the same problems on hackerrank and they gave TLE's . Thats exactly when i started learning number theory the right way. dont get me wrong. Project Euler is good but as a newbie on the platform i never realised how to learn from those problems as i never got tle. so hackerrank kinda fills the place. PS: I too wanna what happend to hacker rank. what did it go down suddenly.
•  » » » 3 weeks ago, # ^ |   +40 I think there's a rule in PE that your code should run below 30 seconds. It's up to you to obey that rule though.
 » 15 months ago, # |   +95
•  » » 15 months ago, # ^ |   +43 > clean and fast website Except friends tab loads idk 10 seconds or more and the correct answer message takes about the same amount of time to be received (I guess insert query in some their database is slow af, as well as any read from the friends db)
•  » » » 15 months ago, # ^ |   +31 But don't we all love the 'oh, this page is slow to load so I'll assume it's AC and move on to the next problem' heuristic?(Only to be occasionally laughed at when the WA page turned out to be slow.)
•  » » » » 15 months ago, # ^ |   +10 I got fooled by that heuristic like 10 times today and man it felt really bad :(
•  » » » 15 months ago, # ^ |   +49 hello will you not ruin my meme please thanks
•  » » 3 weeks ago, # ^ |   -10 lol
 » 15 months ago, # |   +19 I am not an HR representative ofc, I'm just some dude who set or tested the majority of the problems of this contest.As far as I know, Project Euler knows about Project Euler Plus and gave permission to maintain this mirror.Also some words about stealing. Do you really think that taking a problem from PE and1. Making it an ICPC-style problem with multiple tests or even multitest,2. Increasing the constraints, sometimes even drastically,3. Creating a fixed time limit which is smaller than the original one-minute rule 20-30 times,4. Or even taking the original as a template and creating nearly original problemcan be called "stealing and just stealing"?About spoiled solutions. There are some not very intelligent people who create a public source with their PE+ solutions. There are also some people with the same lack of intelligence who created a public source with the PE answers before PE+ was even a thing. Personally I don't like both groups of these people.
•  » » 15 months ago, # ^ |   0 But some people discuss problems in the corresponding threads in Hackerrank, and unlike similar threads in projecteuler, one does not have to solve the problem in order to see the discussions -- moreover, one doesn't have to even be logged in. I think publishing solutions or answers somewhere in public place is not the same as discussing problems in a special place for it, despite it is also public
•  » » » 15 months ago, # ^ |   0 Excuse me, I don't get your point. First you write about HR discussion as a problem but then you say that it's not the same thing as publishing solutions (which is obviously worse).
•  » » » » 15 months ago, # ^ |   0 My point is that while discussions in hr are a public place, hr as a platform obviously violates the rules of pe
•  » » 15 months ago, # ^ |   0 I told about stealing problems sometimes, it's ok if you want to use something or so, but it's a huge collection copied, so it's look like more.Problems are changed, but it's the same intelectual property imo.
•  » » » 15 months ago, # ^ |   +15 Look hereAs you can see the only thing they ask is to put the attribution link which is at the top of every problem of PE+. And of course, PE+ is not a commercial project.
•  » » 15 months ago, # ^ |   0 Are you saying that (almost) all problems in PE+ are unsolvable using intended solutions from PE?
•  » » » 15 months ago, # ^ |   0 Depending on what are these "intended" solutions. I usually read PE forums before creating a problem and see a lot of people who got an answer within several seconds or even minutes. This is perfectly valid for PE, but not for PE+ (and remember that the constraints are usually larger)
•  » » 15 months ago, # ^ | ← Rev. 4 →   +14 I think project euler is quite serious about spoiling solutions (at least recently?). I had a public repo in GitHub a few years ago (yes, Github had no free private repo back then) containing my project euler codes (and got cool 0 stars) and the project euler admin asked me to take it down. Could you just make the forum private before solving as project euler do?
•  » » » 15 months ago, # ^ |   0 Well, I can say with confidence that as soon as HR receives some message from PE with the approximate content "Ok, we take our permission back, please kill this contest or remove discussions or do something else", it will be done. I don't think anything should be changed without this message.
•  » » » » 15 months ago, # ^ |   0 Well, quite simply, reiterating what was pointed out by Golovanov399, HackerRank should at the very least only allow those who have solved the problem to read/write in the discussion page, because it violates the principle of Project Euler.
 » 15 months ago, # |   -19 I am from Hackerrank, wsup?
 » 3 weeks ago, # |   +3 freecodecamp.org also have 480 problems in their archive for coding interview practice. IDK they really asked permission for this. Maybe it's permitted to use their problem in another website, or they don't really care. https://www.freecodecamp.org/learn/coding-interview-prep/#project-euler