how exactly is penalty calculated in short contests?
The rules for penalty are generally given in the Contest page. Time penalty is used only in Cookoff contests, and it is 10 mins as of now.
It is calculated as follows -
i) For any question in Cookoff, it is either correct or incorrect. There is no partial submission. So for every incorrect submission, a 10 minute penalty is added to the Contestant’s total time used. However, that factors in only if the participant solves the question later.
ii) Time taken by a participant is used to break ties in scores. At that time, the total sum of time used for solved problems + Penalties on solved problems is used to calculate the time taken by the contestant.
iii) Among the ones with equal score, participant with the lower time taken is ranked higher.
For example, there are 2 participants, A and B. And there are 3 questions to be solved - Q1,Q2,Q3.
Now during the contest, here is their performance -
Contestant A -
Solves Q1 in 25 mins.
Solves Q2 in 40 mins after 2 wrong attempts.
Could not solve Q3, but made 1 wrong attempt.
So the total time taken will be 25 mins (For Q1) + 40 mins (For Q2) + 10*2 (For two wrong attempts on Q2) = 85 mins.
Note that there is no penalty added for Q3 even though there was a wrong attempt, because it wasn’t eventually solved.
Contestant B -
Solves Q1 in 30 mins.
Solves Q2 in 45 mins after 2 wrong attempts.
Solves Q3 in 1hr 20 mins after 5 wrong attempts.
So the total time taken will be 30 mins (For Q1) + 45 mins (For Q2) + 102 (For two wrong attempts on Q2) + 80 mins (for Q3)+ 105 (for 5 wrong attempts on Q3) = 225 mins.
Note that the penalties of Q3 have been counted now for B because B has eventually managed to solve Q3.
We see that the time taken by B is almost thrice that of A. So who wins? A? Wrong, because A has solved two while B has solved 3 questions. Hence, the winner is B irrespective of the time taken. Time taken, and penalties are judged only if the questions solved is same.
Moral: If you are leading, and you think the next question may not be solvable by you, do not hesitate to attempt it despite the penalties. Because not solving it at all is always worse than solving it with lots of penalties.
Mods, please correct me if I am wrong somewhere.
So for eg. if I calculate Q1 after 30 mins the competition had started and made 2 incorrect submissions. After that problem, I did Q2 for 15 mins and got my first solution right, so my total time would be
A) 30+(2 * 10)+15 or
B) 30+(2 * 10)+45