Regarding the cheating in codeforces round #824, here are some submissions that need to be looked at:

https://codeforces.net/contest/1735/submission/174418316 https://codeforces.net/contest/1735/submission/174422837 https://codeforces.net/contest/1735/submission/174422426 https://codeforces.net/contest/1735/submission/174428235 https://codeforces.net/contest/1735/submission/174428573 https://codeforces.net/contest/1735/submission/174413648 https://codeforces.net/contest/1735/submission/174424155 https://codeforces.net/contest/1735/submission/174427490 https://codeforces.net/contest/1735/submission/174422837 https://codeforces.net/contest/1735/submission/174413565

upd: https://codeforces.net/contest/1735/submission/174420701 https://codeforces.net/contest/1735/submission/174419876 https://codeforces.net/contest/1735/submission/174413565 https://codeforces.net/contest/1735/submission/174411134 https://codeforces.net/contest/1735/submission/174411370 https://codeforces.net/contest/1735/submission/174411138

They use the same language, and the code is very similar, while some of the variable names are changed.

MikeMirzayanov please look into this

Thanks, Leon