Ce Jin Solved Aliens Perfectly at IOI | Generated by AI
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.