If I spend 10 minutes solving A, submit and then spend 20 minutes solving B and submit, I will get less penalty than someone who solves A in 20 minutes, submits, and then spends 10 minutes solving B. This doesn't seem right to me. Seems better to just give people time penalty based on the last AC'd submission (+ possible WA penalties). If someone spends a lot of time solving the first problem, but then quickly finishes all the others, and is done with all the problems 2 hours before the contest is over, seems like that is a stronger competitor than someone who solves all the first problems quickly but really struggles with the last two, and ends up submitting the last AC 3 minutes before contest is over. But with the current system, the latter could potentially fare better.
Is there a reason this isn't the way its done? Not criticizing, just curious if there is a rationale behind structuring the time penalty system this way.
This type of penalty is not unusual. The well-known ACM/ICPC contest first used this type of penalty calculating and CF just copied it. So why not ask ACM/ICPC organizers?
Let me explain. If the penalty is the time that last problem solved, many users will try solve all the problems, and submit them simultaneously at the last time. This makes no difference from submit them one by one, but give them extra advantage: if in the mid time you found yourself uncomfortable, you can quit and this round will be unrated for you.
In other words, you can choose the rounds that make you feel good and abandon the rounds that make you feel bad. This is unfair to users who submit the last problem before going to next one, and also will give huge pressure with servers since in last 30 minutes there will be mass submissions.
That makes sense. I hadn't thought of that. Thanks for the explanation.
I think this kind of penalty makes competitions more fun, as it encourages contestants to submit every solution as early as possible. We can usually see the most up-to-date scoreboard and see how many people have actually tried and solved the problems and make strategies based on them.
In CF, it has another benefit: it prevents people who did not perform well from running away after like an hour.
What I find problematic about CF is that time isn't just a tiebreaker, but it actually determines the score of the problem. This system can lead to situations where a contestant who solves a more complex subset of problems to potentially rank lower than another contestant who solved a simpler subset but faster