Ce Jin Solved Aliens Perfectly at IOI

Ce Jin Solved Aliens Perfectly at IOI | Generated by AI

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Yes, you’re right — it’s Ce Jin (金策 / Jīn Cè), not Qinshi Wang. I mixed up the names earlier, sorry for that.

From the official IOI 2016 results and contemporary reports:

Ce Jin (China) was the overall winner of IOI 2016 with 597 points (very high score, basically perfect or near-perfect across problems).
He is the only contestant who achieved full 100 points on the “Aliens” problem during the contest.
Many sources (including LinkedIn posts, Codeforces discussions, and IOI newsletters from 2016) confirm that only one person solved Aliens for full points in-contest, and that was Ce Jin.

Qinshi Wang (王钦石) is actually a different legendary Chinese contestant — he is famous for early work on the “WQS binary search” (also called Aliens trick / alien optimization) technique in training materials around 2012, long before IOI 2016. His write-ups and ideas heavily influenced the community and probably helped inspire or prepare people for problems like Aliens, but he was not a participant in IOI 2016 (he had already graduated from high school level by then).

So to clarify:

Inventor / early popularizer of the core idea behind the full solution technique → Qinshi Wang (around 2012 in Chinese training docs).
The only person to solve Aliens for 100 points at IOI 2016 → Ce Jin.

Yes, Aliens was (and still is considered) extremely hard — full points required mastering convex hull trick + the binary search on “penalty” (the famous “Aliens trick” / WQS binary search / Lagrangian relaxation trick). Most contestants, even strong ones, only got partial points (e.g., 30–70). Ce Jin pulling off the full solution in 5 hours of contest time is widely regarded as one of the most impressive individual problem performances in IOI history.

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