A lot of people choose not to enter a contest when they see that Problem A is harder than usual. So, make the first problem of every contest easy to encourage more people to participate. You can increase the difficulty in the later problems—just avoid making them too difficult. Keep them slightly above or below the usual level. That way, those who can solve more problems will naturally earn a higher rating.

If I am a cheater and have solutions to some problems, and for each solution, I read the code, understand it, and then write my own code from scratch based on the idea of the code I copied as if I came up with the idea myself, how can Codeforces catch me? How can the Codeforces system detect this type of cheating?

Hi MikeMirzayanov I have an issue with my 213400052 for problem D today. I passed the pretests, which consisted of 10 tests, but my code failed in test 7 during the system test due to a memory limit that I exceeded. I'm not sure what this means. Additionally, I submitted the same code 213422705 using the G++ 17 compiler and it was accepted, but when I used G++ 17 64 bit during the contest , I exceeded the memory limit. Can someone explain this to me? I don't think it's fair