Hello, Codeforces! A month ago I have wrote my blog about cheaters. Under that blog, a number of suggestions have accumulated, and there is a number of interesting ideas that could be applied to sabotage a group of cheaters.
I've often seen comments along the lines of:
Well, doing what Ari suggested wasn't really what I wanted to do, but it was worth checking out what would happen if the wrong solutions were sent. I asked some famous user what would happen if I sent the wrong solutions to cheaters. He told me that someone had done this before and that he was quickly debunked.
I wondered whether I could cheat cheaters without getting caught. But for this, I had to do something. As you may remember from the last blog, I had already been featured in various cheater groups. So I needed an assistant to correspond with cheaters instead of me. That helper turned out to be Dmi34. Thanks a lot to him, without him this blog wouldn't have come out! We were on Discord and I told him what to do. He also helped me with writing code, but more on that later. By the way, don't scold him for his knowledge of English. His first language is Russian, after all.
My first idea was to create a group on CF and invite all cheaters there. Then I decided, that it's not a good idea. That's because it's almost impossible to get cheaters into a group on CF because they would probably realize that it would be a bad idea to leak their nickname. Yes, and how to lure them there? They obviously don't need trainings and training tasks.
So, I decided to stop at dropping the wrong solutions. Since I had been told that it could not be done, I wondered: why could it not be done? As it seemed to me, I found the answer. It was that the cheaters can't be sure that they have the right solution. So we did the following.
Dmi34 started to solve the problems in the round (don't worry, he's not a ranked participant since he's a candidate master), he solved problems A, B, D and E1. After that, we decided to do wrong solutions to problems D and E2. But we had to do it very carefully, because it was impossible to give them even the slightest hint about the solution. Then we did the following: I wrote the wrong solution for D, which takes both WA and TL (although cheaters often don't understand the difference between the $$$O(n \cdot log(n))$$$ and $$$O(n^2)$$$ solutions). And Dmi34 wrote a brute-force solution on E2, which obviously didn't work.
Links to these codes, they will help you catch cheaters:
So, Dmi34 wrote in the chat:
And a wave of cheaters went down! Everyone wanted to know the solutions! We made them wait for a while, and then we started sending them these solutions after all. Here are the funniest and most interesting screenshots of their requests.
We even had two people write to us asking for help with their admissions tests! I'll show you screenshots of one of them.
They soon started to suspect something, but we dispelled their doubts with a screenshot: the rectangle is green, my solution works, look for a bug yourself.
By the way, the cheaters took quite a while to respond. Apparently this is because they were changing the codes to avoid getting caught by anti-plagiarism. However, we still forced them to throw our code unchanged:
Soon some cheater wrote that he had a solution to the C problem. We messaged him that we want it, but he didn't reply to us. Soon we still find out how much the solution to the problem costs.
Also, some cheater wrote to us, asking us to exchange the solution to problem C for problem E2. To my deepest shame (sarcasm), we agreed, and dropped him the wrong code, and got his code in return.
Here's his solution. By the way, it doesn't seem to work:
After having a lot of fun, we decided to admit that they were just being trolled, and threw them funny messages. I thought they would react to it, but almost everyone was cool with it. Amazing calm!
What's funny, Dmi34 kept getting messages asking him for the solutions! Didn't it get to them even after reporting that they were being trolled? It feels like they just don't read the conversation!
The funniest cheater we have found:
Next, I personally joined another group with cheaters. I don't want to advertise them, but their admin wrote a comment under my last blog, you can check it out if you're interested. To my surprise, they... Really banned from texting during the contest! As soon as I joined, the bot wrote a message saying that Wind_Eagle had joined the chat... And I immediately (!) got a message from some cheater who offered me to buy the solution to his problem C. I asked how much the solution cost. So, now, without looking in the spoiler, try to guess how much it costs, and then stop by and check yourself.
I haggled for decency. When he said he was ready to sell, I wanted to write that I didn't need it, because I supposedly just thought up the solution to the problem. But he texted me his wallet number. I will not show it, I do not remember it and his number deleted, because it is too much. However, the cheater himself, I put him on blacklist so he wouldn't write to me again.
Speaking of cost. Remember that group that asked for help with the test? Well, helping on a hiring test costs a mystical <<200>> (I suspect rupees).
Now it's worth telling about my correspondence with the admin of this group. Why tell me about it though, read it for yourself.
So, what can be learned from this blog? First of all, cheater catching enthusiasts — your turn! You can see the codes I sent them, and if you want, you can look for cheaters. Second, I showed you how much the solution costs and how actively they sell. And third, I showed that the tests for joining the company are also being bought and sold, which was particularly disappointing to me.
So what conclusion can be drawn from all of this? This. Cheating — it's not just cheating, it's also a business! So, like any semi-legal business, it is extremely difficult to eradicate.
P.S. Dear cheaters, please forgive me for the inconvenience! I did not want to hurt you too much, in the end, you will get back your rating in a couple of contests. All our wrong solutions you got as quickly as possible and for free . If I caused you any inconvenience, please forgive me! I won't do it again!
P.P.S. Thanks gepardo for checking the blog.
Sorry for typoes in the messages. English is not my first language, and when you are messaged by many cheaters, it is hard to concentrate.
50 Rupees for solution in C++, 70 rupees for Java.
I have never laughed so hard.
WHY JAVA MORE???? WHY????? LOL
Java solutions are longer.
Who wants to write CP in Java?
I laughed even harder seeing your username and pfp.
that's entrepreneurial
Cheaters be like: This is bizness
Prices will probably drastically increase during chinese rounds
trapforces
I've heard that many software companies in India shortlist candidates for interviews based on their ratings on CP sites like Codeforces and Codechef. This could be one of the reasons why there is such a huge incentive to cheat.
Bruh I am Candidate Master and I can't even land an internship right now. :(
I know the pain :`(
Codenation CodeAgon on 3rd Oct
I don't think they do. I never got shortlisted :)
callmepandey saar ORZ....
@callmepandey Orz
This is exactly the reason why cheating is so common. Please stay away from this misconception. CF and CC ratings DOESN'T matter in interview. Your skill certainly does! Why spoil CP and CC/CF contests for fake ratings!!?
software companies in India shortlist candidates for interviews based on their ratings on CP sites
Real rating (not cheated one) will only help you in coding round. It does not affect other rounds. So, rather than gaining false rating one should focus on other things
Yeah, getting a job is unrelated to CP skills. I tried a lot and wasn't able to get an internship.
Doing the work of gods. How can I thank you guys enough?
It's so sad to see that most of the people in these messeges are speaking hindi and therefore probably from India :(
It's interesting that they also try to write in Hindi in DM while asking for solutions. Do they think that all the members of such groups are also Indians or are just lazy to switch to English?
They were not expecting any foreign person to help them. They assumed that the person on the other side was an Indian person who had the solutions and would ask for money.
This is my theory and might be entirely wrong.
In India it's a trend to speak in "Hinglish" It's kinda a mixed form of Hindi + English.
I'm really disappointed at this situation, people want shortcut for everything, so desperate for solutions.
Very sad, that guy who was boasting that they can never stop him, such shame they bring to our nation.
OK, I want to ask MikeMirzayanov to ban saurabhbera11 for cheating. For sure, I have proofs.
At first, look at my blog :) He is here in the picture titled "the funniest cheater"
At second, look at his submissions on task D. Yes, you will find there our wrong solution, that was written to cheat cheaters.
https://codeforces.net/contest/1579/submission/130146949 https://codeforces.net/contest/1579/submission/130149784 https://codeforces.net/contest/1579/submission/130164446 https://codeforces.net/contest/1579/submission/130167047
So, please, I hope, that he will get banned.
Also I hope that shashanktrivedi.official will be banned for the same reason. Proofs that he is a cheater were in my previous blog: his nickname was in the YouTube video, that was posted during my Codeforces 741 Div. 2 Round.
Please, ban these users, let the banhammer speak!
what an irony , the one whos calling u d*ckhead is probably himself one for not being able to solve even a single simple problem in a div 3 round . What a pity .
During Codeforces Round 695 (Div. 2) I said in a telegram cheating group that the solution to B is max(0,sum-25)). Due to that I got about 10 DMs and you'll find surprisingly many people submitting that if you look at shortest WA2 solutions to B. I also said that the answer to A is 50n^2-61n+20, though I think such A solutions were a bit less widespread.
Lol, this is fuuny XD
Cheaters are much more gullible that I thought...
This makes me laugh and sad at the same time.
Good job
wow people believed you? where does 25 come from?
25 is needed there to pass the samples included in the problem statement. But it could have been any other nonsense formula, which happens to give a correct answer for the samples.
You're a legend
Next time settting a contest you can troll them like this :
Then what happens if the cheaters can't solve the problem, but are able to read the code and fix these minor changes? You are basically giving them a free solution...
Because cheaters are gullible so let hope that they rather looking for next problem's code than checking a pretest-passed code :))
Great work. It can get even better when a setter is involved. Writing code to just pass the pretests and adding system test to block that solution intentionally. Then that code will spread more fast and trap more cheaters.
MuhammadHassan hhhh
XDDDD
we ana b2ool fe acoad kteer et3mlha skip leah XDDDD
Why do Indians got to be cheaters? Cheating is useless. Even if you increase your rating by 50/100 whatever you didn't learn anything. Ashishgup works in Google not because he is some BIG GRANDMASTER on CF. It's because he did CF improved his skills and cracked Google. I feel sorry for those fucks and don't judge Indians by this.
Is it possible not to judge Indians after looking at the screenshots? We Indians are responsible for our own collective misery.
By the way, Wind_Eagle, you may get some (actually a lot) of hateful texts from Indians in a mixture of languages. Please post screenshots of these too so we may enjoy a little more!
Yes i am a absolute noob in Cp. last contest I used ideone.com and wrote my code and developed logic with my own mind. Later I got mail from CF stating that your solution is matching with someone. I wondered what the fuck is this. How could someone cheat like this??. For the div3 contest I decided to submit my codes twice and stating my username in comments like //Nishant_Mohanty. Although I did not use ideone.com. Now I wonder what will happen??.
Why did you use ideone.com?
I have used ideone to share our wrong solutions :)
I would say you are doing a great job. I wish all the newcomers get aware about the situation as soon as possible.
Dont lie. You are already one of those that are simply copy and pasting the solutions
Ok tell me a random Question which you want me to Solve.Give me your expected time within which you want me solve. if I could not solve it then would you believe. If I could able to solve it feel free to complain. If you are interested to duel please tell me. I will surely be pleased to destroy your pathetic accquisitions. anyways its fun to reply nerds like you.
Bruh wtf XD. You are grey. I am blue from my main ID.
Why do y'all want to cheat anyways? What do you think would be the reward?
I think i must to The Codeforces team that someone with random account who has not given any contests is harassing me. I think that would be fair enough.
Are you guys competing for negative contribution?
This blog is the most funniest thing i've ever seen in CF !!! laughed so hard... and the bargain.. it was EPIC !!!
Good work!, this will at least make those cheaters aware that they can be curbed so your work was not in vain, from what I see through the DMs, cheaters feel proud after cheating and think that no one can stop them, such narcisstic atttitude from cheaters who can't even solve single problem even in a Div3 round is toxic not only for the sport,spirit and platform but also human morality in general.
Just prepare weak pretests.
it could be fatal to innocent noob-coders like me who mostly get their test case wrong at pretest 2, and then rethink what's wrong they did and comeup with better idea/solution.
Don't participate in rounds while you are noob-coder. Solve archives instead, it's more profitable.
most people suggest to do contest and upsolve.
(。_。)
No, make a silly mistake in a correct solution and then mine random tests for one where it fails, then put it in systests and offer the cheaters the bugged solution. They'll NEVER know the difference.
That's what I mean.
Btw, long ago, when pretests were not equal to systests, when we witnessed hacks, were there any cheaters? I don't remember any!
What I suggest are strong pretests — they punish a mistake nobody would realistically make.
When we had a lot of hacks, CF was much less popular and pretests tended to be rather worthless. Tough to compare.
Why not charge a little fees (like rs. 1000) to join codeforces and give the collected money to problem setter (so that they will become more happy :)). This way, the number of cheaters will decrease eventually (As we know, cheaters find easy ways in life, and giving money is not one of them).
Good idea
this would definitely decrease cheating, but this would go against the basic ideologies of codeforces or any other online judge for sure.
Cheaters are literally offering money for solutions as all these screenshots show. They are already prepared to pay. On the other hand, many honest participants will quit if any paywall is introduced.
Don't you think honest participants participate more in ICPC compared to cheaters as there is fees assocaited with ICPC ?
You got it wrong. Dishonest people cheat on CodeForces, because it's easier to create a CodeForces account, and it's easier to cheat here. For ICPC, you have to be real good (which means normal cheaters won't have a chance), and it's hard to cheat at the ICPC using the same way they cheat here. Money isn't necessarily the problem.
Yes you are right, I was not saying that the number of cheaters will become zero, but it will decrease definitely.
Wind_Eagle orz My rank was about 4.0k when the hacking phase was about to end and now it's 3.7k
Mine was 6.1k during the contest and it went to 4.9k finally . Thanks MikeMirzayanov for the plag checks :)
Thanks :)
It is sad to see people from India cheating in the every contests. I don't know when people will stop running behind ratings and stuff. look at me, I got into a good company despite being newbie. other skills matter too!!
DM me if you want Hindi translations during this trolling. Will be fun in the next div 3.
LMAO, this is gold
Now this has become a normal trend, what else can we expect from these Indians. Now please don't come crying saying don't judge all Indians just because of these cheaters. Then what else should we do ? Have anyone ever seen people from other countries cheating at this level ?
Don`t even wanna argue with you on this one... Really sad to see what people of my country are resorting to..God knows when this will stop.