I got a message from 'system' that
Your solution 123456859 for the problem 1551A significantly coincides with solutions skjha98/123456859, Nedtofigo/123472639. 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.com/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.
My Submission is : 123456859
Our solutions do match exactly the same, however neither do I use Ideone or any platform where my code can be leaked and neither have I given my solution to that person. I am beginner so I have started to code using VSCode with autoformatter, that might be a reason for that clean formatted code. It seems like a coincidence since the solution was simple that it matched almost exactly, but I have no idea how we have assumed the same variable names. Please let me know what else can be done.