I have received an official message:
Attention! Your solution 193296720 for the problem 1793C significantly coincides with solutions Autreekt/193296720, karthik_2002/193327533. Such a coincidence is a clear rules violation. Note that unintentional leakage is also a violation. For example, do not use ideone.com with the default settings (public access to your code). If you have conclusive evidence that a coincidence has occurred due to the use of a common source published before the competition, write a comment to post about the round with all the details. More information can be found at http://codeforces.me/blog/entry/8790. Such violation of the rules may be the reason for blocking your account or other penalties. In case of repeated violations, your account may be blocked.
I found out that we did have exactly the same code, but I didn't know him. I didn't touch anyone during the competition. I think he got access to my code by some ways, but I don't know why.
His submission was almost an hour later than mine, ruling out the possibility that I copied his code in the first place.
During the competition I used a local editor and didn't use any online editor, so there is no possibility that my code is made public.
So I think that he would have had some tools to crack codeforces or a temporary problem with codeforces and thus stole my code.
I earnestly request to look into this matter to prove my innocence. Thank you very much.
Hmmm, I guess that's how it happened : Cheater Locked Problem. Looked his room and found you. Also copied your code for using it in his main account.
I hadn't thought of that possibility before, thank you very much
You are welcome. I suggest you wrote mail in this situations...
This is dangerous bro...I hope codeforces finds out a way to remove this possibility.