I did not give today's contest today but accidently I looked at the scoreboard and found a lot of submissions for problem A, B, C , D which were much higher than usual.
Hence, I looked online and found that all the solutions for the first 4 problems were leaked.. HERE are the screenshots. I don't want to share the link of the website , it's just for reporting
PROBLEM — D Training Session Solution
PROBLEM — C Delete Two Elements Solution
PROBLEM — B Groups Solution
PROBLEM — A Computer Game
i hope most of the cheaters just copy pasted the solution and didn't change anything.
Including him he himself is a cheater. See This
https://codeforces.net/blog/entry/95847?#comment-849533
Sadly they didn't do any plagiarism checks. Even if they had blindly copied they are not caught as none of the submissions are skipped...
'Only for educational purpose'
Seriously?
The contest is called "educational" contest so it is 100% for educational purpose.
lol Yeah !! But guys get Dijkstracted. :) easily.
damn thats bad(like the round)
The round itself was fine.
This is straight up disappointing. D getting this many solves definitely caught my eye!
The fact that it is done by a range of ratings from experts to newbie is just crazy.
1. Marshmalloc
2. HAGIAAN
3. roni-2001
Some trying to be slick by changing variable names
1. malik_madani
2. unbeatablekks
And there might be hundreds more but man I am too disappointed to search.
I am disappointed that even a not so fellow blue would resort to that. Society is fucked man
They are blue because they resorted to that
Maybe, but by the time of submission and his rating graph i assume he was afraid of demoting and copied the code in the last second. If he constantly cheated he would've submitted earlier and with more changes in the code
Actually I think today's D was easier than Friday's D, and back then it also had 1500 solvers, which was much more suspicious to me
I also think today's D was easier than usual. I'm actually a little surprised with the few number of solves of D, and I associate this with fewer participants.
That was exactly copied problem from INOI 2021 and it's solution of all contestants were public on contest site at codechef
Although it is still suspicious because in INOI there are extremely few submissions during the contest
D is a known problem. I remember 3 or 4 similar problems with exact same solution. It's this type of problem that needs to be solved 1 time only so the next time you know how to deal with it
Aren't most educational round problems like that ? They are "educational" rounds after all :)
i don't know. i hate educational rounds. i wrote that one because i need rating :D
So it isn't too much to hope for a significant ranking improvement after the plag-tests are run, ig.
All submissions have integer overflow I guess. As they are multiplying size of two vectors directly without typecasting.
Even the leaked one did the same mistake
I used vector size in my code, too. Things go well on my computer. However, the same code reports a WA 14 on codeforces. Can you explain further about the issue?
WA14:131482168. Hacked: 131448614. Their test cases are the same, which is generated as follows:
size_tisunsigned long intand on your compiler it may be compiling as 64-bit integer but not on cf, try usingc++ 17 (64). I submitted your code withc++ 17 (64), got acceptedI don't want to share the link of the website
THANK YOU! FINALLY SOMEONE SMART!
Not SOMEONE. I am the same person as before
Ah, you've learned. Great! Thanks
How will you report that website??
Can't.
It's there for a long time. They first upload videos on Youtube showing the solutions and post it in their website.
Actually probably it can be DMCA'd because the problems are copyrighted by codeforces
Color me surprised! (and Cyan :P)
Cheating increased because of dumbos like you. Many people who are cheating now wouldn't have got the idea to look for answers online if you ppl haven't posted blogs like these.
Cheaters don't stop cheating by reading blogs like these, but more people will take that path instead.
Does CF's Plag-Checker only compare submissions of participants with one another or are some of the leaked solutions from websites/apps (validated with the help of timestamps) also considered?
If they aren't being considered right now, maybe there can be a way for users to make submissions flagging these leaked solutions (with timestamps) in the period between the plag-check and the conclusion of the contest?
It is said that, "There is no such thing as bad publicity" XD.
I am sure most of the cheaters(as well as the site author) are Indians. Stop spoiling the platform for all of us.
What do you want exactly? Should every Indian leave codeforces? If no, for what reason would you bring nationality in a discussion about cheaters?
lol wtf !
I agree. Cheating happens mostly in India.
And it all started because of this and this
PS: The videos are in Hindi. So you won't be able to understand what they are saying...
India's population in largest in world . Even India and china combined population is 1/3 of world population . By watching these fucking piece of shit you can't blame whole country.
Damn, the guy introducing the first video should considering becoming an auctioneer or a rapper...
He went with the latter.
I m also Indian ,and the above statement said by Itami-san is the sad reality of India because of the fact they think showing of 4-5 star or blue/cyan on there resume will get them better chance at Placements ,this hyped up when many placed in good company on Youtube started telling 4-5 star or master/expert will get easily shortlisted for interview, and that's how everything began.
Hmm, I do get the interview part, a lot of people use CP as a means to reform their problem solving skills. Also, there are a lot of top performers from India in almost all contests, so it's not entirely right to judge people with some videos(or my comment for that purpose).
The only possible solution could be introduction to CP at a relatively earlier age — before university or late high school days — that might change the perception of CP being an interview tool to a competitive sport.
Ngl 99% blogs related to cheating on CF are from India or involves Indians.
And 100% of them are related to humans. That doesn't mean that all humans are rotten.
No one here is criticising ALL the Indians or entire India, neither does it mean that all the Indians should be banned. It's just a statement that MOSTLY Indians are cheating. If you find it so insulting, then there's definitely some truth in it.
It's just honest criticism, I'm not sure why the arrogant replies here?
I think Div1 contests are much better if you want a fair contest. most of the cheaters are specialist and below
It is probably true.
Yet advising to get to div1 to not compete with cheaters is pretty much like "better be healthy and rich than sick and poor"
Hoping to push to Div.1 soon! While losing some rating points to cheaters doesn't really mean much to me, I'd like to participate in a pool where there's a common respect for platform integrity and fellow participants.
Dude there are cheaters in red lol
Wait-
what?!
May I know what is the standard practise for dealing with cheaters? Compare the code? Timestamps? pls
Similar Memory size/Time execution of the code and similar time of submissions...
or turning
int a,b,c;
into
int im,nota,cheater;
I wanted to hack some solutions on D and found these submissions: 131451583, 131451918, 131445055, 131445378, 131446713, 131450007, 131456045, 131444023, 131447078, 131450582, 131446514, 131453109. You can find more here and here
UPD: Lol, they are all hacked now. Someone shared a wrong solution.
Wow most of them are the exact same code, variables as well.
https://codeforces.net/contest/1598/submission/131453998
https://codeforces.net/contest/1598/submission/131444895
https://codeforces.net/contest/1598/submission/131455144
These will get hacked too.
Second and third won't. I have just tried.
If these cheaters are not severely punished, Codeforces rounds will be boring by these cheaters sooner or later.
Maybe the statement $$$ (top[i].size()-1)*(dif[j].size()-1) $$$ is hackable because it would return an unsigned int which may not fit for $$$2*10^5 * 2*10^5$$$
How to upload this test? I created this test but size is too large (1.7 MB) to use as hack.
Edit : Got it, we can upload a generator as well
Can we discuss hacks while Hacking Period is not Over?
There are no points for hacking in educational and div 3 rounds
I am not sure about this one.
vector::sizereturns asize_t(same asunsigned long int) value which will not overflow. Can anyone tell the hack tc for these solutions?Hacked about 6 solutions using this
hey do you know why isn't it working on my code?
So it turns out that
unsigned long intis 32-bit on CF's 32-bit compilers and 64-bit on the 64-bit compiler, which is what you used (you can check this on custom invocation). So it overflows on the submissions which were submitted on C++ 11/14/17 but is fine with C++17 64 bit (thanks to aryanc403 for telling me this).Thanks a lot, i was lucky today.
I made this account to comment stuff that might come across as controversial. You just cant simply end cheating at all. Proof? Look at big games like FIFA and COD and all that bunch you'll find tons of cheating going on with ease and they're way bigger and more developed than codeforces and that is not bad on codeforces' side but rather proof that eradicating cheating all together is just impossible. Now you might ask so what to do? Simply just dont care anymore. Honestly at this point it is not worth it at all to just feel anything towards any type of online contest. Cheaters will be there no matter what and blogs like these only open more eyes upon such resources. Because why will any newbie just bother when he can just see thru the blog this type of stuff then put any effort? Add to that there are more issues to deal with than cheating. Have you seen the state of round 3 contests? literally the worst place to ever try and put effort in. 2 day old accounts solving all the tasks with ease, sounds suspicious yet you never hear of it. Also these solutions dont come out of thin air, cheaters are simply not this capable so if you really want to solve it get to the root and find who puts out free AC code that is seemingly well thought and coded than a bunch of cheaters that are clueless headless chickens. Also at this point we see a new cheating blog every week is it really worth it to boil your blood anymore or just care? Just do the right thing and stop caring so much about a number on an internet site that holds no weight in real life. Until we see action against such people then I dont think it's really worth it to keep shouting. Btw, in no way i mean any disrespect against mike it's just and impossible task and that needs to be admitted.
Maybe these accounts are just new accounts registered by some strong contestants for competition.
That is wrong though. Tell me what is the difference between that and some newbie having another account and uses both in contests? Nothing. Moreover, it means some insecure topcoder is using his power to steal ratings from others who might not be as good. Still a horrible thing to do.
Who told you that if a person registers multiple accounts, he must use them at the same time in a contest? Can't you just use one account in a contest? According to what you mean, if a person has two accounts at the same time, he is cheating? That's obviously wrong.
Every square is a rectangle, but not every rectangle is a square. Every plagiarist is a cheater, but not every cheater is a plagiarist. The users of multiple accounts are just a different variety of cheaters. Some of them do this to gain an unfair advantage for their main account. The others only harm the system without any direct benefit for themselves. Either way, having two accounts at the same time is forbidden by the rules and there's a good reason for that.
Imagine a plagiarist creating a new account with a random name, submitting copy/pasted solutions with some obfuscation and then immediately abandoning this account after the contest. Does he gain any advantage for himself by doing this? No. Does only sabotaging the system without any personal gain magically make this behaviour acceptable? I don't think so. But the owners of multiple accounts may disagree, because this is similar to what they are doing.
Btw it is prohibited by Codeforces rules to have two accounts
I mean, you're probably not that justified in claiming that "someone is new to codeforces AND is not another account of another user" == "someone is new to comp programming" -- after all, cf isn't the only such platform out there. Plus, if someone solves all the tasks, it is unlikely that it is from cheating -- how often do you see 3000-difficulty problems' solutions leaked? Who would be able to leak them?
edit -- my bad
you totally missed my point. It's okay I'll boil it down. A lot of the accounts you see in Div3 contests that are new are never touched afterwards basically meaning that the account was only made to participate in this contest then it is thrown away. This is sabotage of the contest and cheating its integrity. Plus I am not implying they cheated as in copying code but as in participating as someone who they arent in order to sabotage the contest. People like these take places of rightful people decreasing their rating. If the case as you are implying this means that this account will remain active afterwards and participate more but that is not the case these accounts are thrown away and not used after and you can look them up and see that.
thanks for making it clear -- my bad
Upvote this comment if you support banning Indians from online contests.
Good lord, tons of downvotes from Indians!
Even if you said that about other race or nationality, I would punch you in the face the hardest I could, not thinking of the consequences. Being racist is so fucking retarded, fuck you, bitch.
LMAO
Funny right? Dumbfuck. You're a shitty pupil as well, couldn't code shit to even get to blue even in 17 fucking months, should've known who I was replying to. LMAO
should've known who I was replying to
Lol you replied again, making your point completely invalid.
Listen, idiot, that was purely for shitting on your peanut brain. I just find racist cunts disgusting. You're a loser anyway.:) And an alternative to all my comments to you would be- shhh, pupil
That "peanut brain" punch was so mature
Punishment suggestions for cheaters: 1) Rip of their arms. 2) peel their skin 3) place them in HF. Peace :)
wow. insert variables by yourself and It is only for educational purpose. does this even make any sense?
This is absolutely madness, almost every contest is breached by cheaters, the fact that we as a community are unable to do anything makes these cheaters grow each passing day.
Soooooo.... Why bother? D solution is poorly written here, so it will be hacked, isn't it? )))
Finally someone who is actually sensible. D needed better constraints. Hacked solutions are a 100% right so far it is just int overloading that hacks them not actual cases.
vector dif[i].size() and top[i].size() aren't long-longs, so their product can overflow — for example when they both are 10^5 each.
To explain, if the authors of problem D really wanted the numbers to go so high they would've done so themselves and it is a very common practice in CF rounds and nearly every problem has those type of testcases. But the testcases this time don't go this high meaning that the authors probably didn't want them to reach such number for a reason (int overflow). So basically meaning either the constraints are unclear or the testcases are poorly written in either way it doesn't negate the solutions as they're correct solutions.
But then, there would be no "educational" hacking! It would be bad, very bad )))
Hackable Edu's is a long tradition )))
Hi, Can you please share the link to this website?
Yeah sure !!!
Here it is. You can find any solution from here
Your link is broken. I've corrected it.
It's working now...
In codeforces they don't add https:// automatically XD
On the other hand, I was detected as a cheater because on round 747, my B submission coincides with horizon2 B submission. Note that I use the template of jiangly and the B's solution is way too simple enough to put me into this situation. If I am faster in implementation, maybe horizon2 is punished :)) Have a nice day.
People like me are dying of solving $$$2$$$ or $$$3$$$ problems during contest but couldn't find a proper approach sometimes or misses one or two corner cases or takes longer time to solve the problem each time hence decrease in rating and there comes these guys. Just copy paste others solutions and become $$$blue$$$ overnight.
abcdqwerty12345 Why do you even care The number of contests you appeared in are less than the cheating blogs you made. You are just a spam and noting more Please ban him
Well, I care about cheaters too :)
Bored From reading these post. Let Them Cheat from now if it gives them happiness, Realy they can't go far beyond CM due to late submission, so clearly they Not Comming in Our way xD.Just Focus On self Improvement :)
Candidate Master
We are not even pupil :) :) :) :) :)
I will Be 2000+ Rated Next Year Same Month guaranteed XD. Marked This Comment For Reminder :):):):)
if we hope for better codeforces so act, every one try to hack 5~10 codes this will clean the mass around and they will stop doing it.
this is only when the cheaters themselves screwed up -- if the cheaters' code is correct then we have no wae
Have you considered the fact that ABCD were all easy problems?
I solved A in 1 minute, B in 5 minutes, C in 5 minutes, and D in 16 minutes.