DuyNgaDocTon1410 is an AI cheater.
Firstly, let's look at their performance. In his first Div. 2 round, they place 22nd. In the next one, they places 2nd (as a pupil), solving every single question! The same day, they take another Div. 2 contest, and fail to even solve two questions, ending at to 6690th place, despite attempting B, C, and D multiple times. Remember, they just got 2nd place a few hours earlier. It is not possible for a human to vary this much in performance on the same day.
Now, lets look at their submissions. One thing immediately caught my attention: out of his 100 most recent submissions, 33 of them are WA on (pre)test 1, and 5 are compilation errors. So this person doesn't test their code before submitting, and doesn't even check if it compiles. Very common among AI copy-pasters.
If we look at the code in these submissions, it is not immediately clear that he uses AI. However, there are too many signs of AI for this to be a coincidence. For example, most of his submissions have no comments, while others such as 310106426 have some of the most detailed and perfect comments I have ever seen. Another discrepancy is his header usage: some of his solutions use bits/stdc++.h, while others include each header individually, and one of his solutions even uses both (which is completely useless). There is even more evidence when you look at his coding style.
Altogether, DuyNgaDocTon1410 is obviously using AI to cheat. Nothing else can explain this amount of evidence. Please ban him and all other AI cheaters so that Codeforces remains fair.
Unrelated: while looking at several of his submissions my account got flagged as being used to crawl, but I was just browsing through his AI submissions.
is this even real? cheat to AK div2 and got ranked 2 using AI.
is there any hope left in online cp?
there is this guy too aura_100 , AksLolCoding , i request you to pls mention this guy too in your blog this guy became expert so quickly i was suspicious and turns out i was right in my suspicion , we are now in age where we have experts cheating!!!! pls check these out too .
i will provide proof that this guy is an AI cheater and coding style of this guy got changed from 2024 to 25 just because of using AI and also other yt channels which share the solutions of ongoing contest.
proofs:( i am sharing some part of code which they did used to avoid getting caught )
https://codeforces.me/contest/2074/submission/310039609
https://codeforces.me/contest/2075/submission/311132247
use of useless variables again . also the amount of times this guy modified the code using ai is astonishing after each wrong attempt!!!
https://codeforces.me/contest/2075/submission/311090104
vector rVec; map<int, int> rMap; unordered_set rSet; ```
same setup for avoiding plag checks
https://codeforces.me/contest/2075/submission/311120009
```
vector<int> rVec; map<int,int> rMap; unordered_set<int> rSet; for(int i = 0; i < 10; i++){ rVec.push_back(i); rMap[i] = i * 3; rSet.insert(i); }```
also notice the code transition from 2024 to 2025 in his/her contests!!!
i am amazed to see this guy is not yet banned !!!!
the community can also see now in latest submissions the(latest contest) guy made also is very suspicious , i can show more proofs later if needed to prove he/she is AI cheater also some sols will mostly match with other cheaters for some of the questions (will share proof later if needed for this too) , for now i think this should suffice.
Hope so MikeMirzayanov Vladosiya will take action quickly.
they also happened to have their first contest as skipped too surely ban these guys
yeah good catch , also they seem to be this user in codechef .there also they are using ai to multiple submit and cheat . https://www.codechef.com/users/builder_20
I am definitely not defending this guy, but a difference in performance can't be an argument in exposing a cheater. For example me. 2 contest ago I solved 1 problem getting 9070th place. 1 contest ago I solved 3 problems getting 1374th place and today I solved 5 problems getting 21st place(all 3 are div 2 contest). The performance can differ very much and depends on the problems themselves
It may be circumstantial, but it is evidence nonetheless
Hi man, I've recently made a platform for leetcode contest plagiarism, and would appreciate if you could visit the site once and let me know how you feel using it.
https://www.similarity.in/
Any suggestions are appreciated, do let me know!
Website looks cool and functional. Reloading the page/duplicating tab causes 404 tho which is very annoying
ohh, will just get it solved, thankks :)
If you look at his submissions during contest, you can see clearly the classic lines of commentary by AI
I'm actually extremely interested as to why crawling isn't allowed on CF.
I was trying to make an automated plagiarism detector and CF is the only platorm that has put a huge effort into not making it possible. With a couple of tricks, i could even make Leetcode let me download thousands of submissions without flagging me.
What's the point of these restrictions?
that implies you have a plag checker yourself, do you? is there any open source plag checker?
There are multiple open source ones. None of them are perfect (obviously), but they're a good starting point. example
Well surely there are multiple open source ones for this (which is infact a good thing), I built this platform as a one stop solution for people to find all cheaters and easily report them as well.
And yeah as you said, this is just a starting point, will be working on this project to build something better.
Btw any advice or suggestion you could tell me after checking out the platform?
Hi, I've actually recently made a plagiarism detection website for leetcode contest,
https://www.similarity.in/
Would appreciate if you could use this website and let me know about what all can we add, what's currently bad on the platform or any kind of advice is much appreciated
My guess is AI companies crawling submissions and overloading codeforces servers. For AI to be able to solve such high rated problem, there's no doubt it's been trained on quality codes, and one of the biggest sources for quality codes and problems is codeforces
Codeforces have to take action on this!
Hi, I've actually recently made a plagiarism detection website for leetcode contest,
https://www.similarity.in/
Would appreciate if you could use this website and let me know about what all can we add, what's currently bad on the platform or any kind of advice is much appreciated
I think it's high time codeforces introduce a report feature.
I guess there is lots of AI users in the CodeForces now...
Like the last edu round, the rank150-210 has lots of pupils, newbies and unrated...
Of course I admit that there may be many newcomers joining CodeForces, but it is true that some of their submission time and code are abnormal [like 1:30 submission A, and 1:50 solve all the problems from A to E].
But it is hard to identify them because they will make all kinds of excuses. Yes, AI users will hardly be punished. They can easily change to a new account and continue to cheat. . .
I think Mike can use some more severe measures to combat cheating, such as banning IP segments or HWIDs.
This may be difficult to do, especially for HWID blocking. Maybe CodeForces can be transformed into a software, but I think the development cost may be very high. After all, I think CodeForces is a non-profit organization/website.
Is it really possible by using AI to AK div2?
I think it's more probably that he(or she) got the code by his/her friend.
I think this is possible in some classic questions.
For example, Edu Round often gives some classic questions, and I think AI may have been trained on similar questions.
This div2 was easier than usual