I found these two cheaters in Yesterday's contest ( Codeforces Round #660 (Div. 2) ). They are from from the same institute (Jaypee Institute of Information Technology, Noida). They have been doing this in all almost every past contests they both participated. CF authorities should atleast disqualify them from Round #657 , as they have gained positive deltas from that round unlike other rounds where they have dropped.
User 1: Agraj Garg agrajgarg
User 2: Vatsal Agarwal Warhead38
Submissions(For CF Round #660):
The solutions are similar, in some contests they change variable names but in many they haven't bothered to do that either.
Submission time differ by 1 min (time to make required changes)
Same Number of solved problems in every contest
Same accepted submission with variable change
For Round #657 ->
For Round #658 ->
For Round #660 ->
Maybe if you present me with 2 similar looking submissions, I cannot definitely say whether they cheated. But it is very very suspicious for 2 users to have such kind of similarities in all the problems in a many contests.
I know CF team is very busy with more important things but I think pointing out even a single cheater is still worth it. Kindly take appropriate actions MikeMirzayanov to stop such activities happening on a regular basis.