Lunchtime contest ranking

I have a doubt concerning the ranking mechanism in LUNCHTIMES (in particular the tie-breaker). I don’t have much of a preference but it would be nice to know. Lunchtime rules say

Those who achieve the score first will be placed higher in the ranklist in case of a tie.

Phrased in another way this seems to mean that a tie is broken by the latest submission time of a solution that increases the score.

On the other hand During the contest I witnessed people increasing their score and being placed before someone who had already reached the same score. While this might be due to lags in updating the ranklist, there is more. The scoring data includes a filed named “total_time”, and tie-breaking is consistent with the value of this field. This would be fine if “total_time” meant time of last score-increasing submission, but it is above 3h for most participants. In fact it is (at least for me) more like the sum of of last (score-increasing) submissions for all problems.

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Hey ceilks, In case of a tie, user achieving the score first in least total time will be placed on top. Where total time is the sum of the times taken to achieve best score in each problem users solves respectively. (This is not what happens at the IOI, but we take the liberty to break ties here). Essentially, it is an ACM ICPC styled ranklist minus the the penalties. You can also refer to our IOI Rank list explanation, which we think will help. We hope this will help. Should you have any further doubts, feel free to get in touch with us.