I was browsering and organizing my team's vp records on the gym. And I noticed that one of our records has disappeared from the standings ( https://mirror.codeforces.com/gym/104611/standings ). Soon I discovered that our vp record appeared below all the participants, which means that our record has been turned to practice for some reasons.

I'm curious to know if someone make our training to practice for whatever purpose, or if we triggered some kind of codeforces' singular mechanism?

Is there any measures to prevent this behavior? For example, sending an notification to the affected participants after to practice action was taken, and providing some sort of ways to appeal for a recovery?

Excuse me, can anyone tell me how to use printf to output long double values?

I tried to use %Lf, but it just output zero when I chose GNU C++11.

However, I got AC when choosing GNU C++17 (64).

Can anyone tell me what should I do? Thank you~

GNU C++11 submission (WA on 1): https://mirror.codeforces.com/contest/1209/submission/92331960

GNU C++17 (64) submission (AC): https://mirror.codeforces.com/contest/1209/submission/92331832