I used AI to fix my grammar, so this blog might look like it was written by AI.
So, recently, I participated in a school contest that had pretests. I was quite sure that I was going to get a high rank; however, after the system tests, I was disappointed to discover that I had forgotten to define int long long (and forgot many other stuffs), which ruined the whole thing.
So, how can I get better at handling pretests? I'm not talking about Codeforces rounds, because on Codeforces, the pretests are equal the same as the system tests.








I'm facing the exact same issue too.
Get better at problem solving!
Just get better in problem solving in general
might you not mind sharing the contest link
One thing that I have noticed in general is, when the idea you are thinking has a very bad implementation, that might not be the intended solution, because most questions have intended solutions based on 1 or 2 ideas. If you feel your way of thinking is clean enough, that is when you implement the solution
Learn to generate random tests and write code carefully and clearly (avoid overflow, MLE, RTE, corner cases). It’s less critical in online contests since you can resubmit, but in offline contests it’s essential if you’re starting CP. (I used AI to fix it because my English is bad)