In a Codeforces Round 880 contest in the problem C (Div. 2) (or A Div. 1) I have got a time limit when I used C++17 (submission: https://codeforces.com/contest/1836/submission/210134408) and have got AC using C++20 (https://codeforces.com/contest/1836/submission/210135600) with exactly the same code. Of course my solution was not optimal (I used binary search), but my question to the community is why C++20 submission is faster? Is it a general fact, and hence it is better to use it further? Thank you for answering.

I've got a letter:

Attention!

Your solution 199960933 for the problem 1810A significantly coincides with solutions hhux/199958881, ElamHarnish/199960933. 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.

It is just coincidence. It happened that we have similar template with hhux, though we even do not know each other. I'm very sure that there was not code leakage (As I understand my submission was a bit later) It means that anti-cheating system can make mistakes.

I bother about how to write a code in order to avoid such false positive mistakes of the system?

I understand that cheating is a problem, and I want the anti-cheating system to be very accurate. MikeMirzayanov, maybe this case will help to improve it.