Grand Archive

What harbor can receive you more securely than a great library?

Problem Sets

CCPC 2018 Jilin Onsite [Solution], Problem I and K are dedicated to Mr. Kazuki Takahashi, Dr. Richard Garfield and the people who ceaselessly bring happiness and integrity to this world.

National Olympiad of Informatics 2019, Problem A is dedicated to my beloved girlfriend.

Asia East Continent Final 2021, Problem J is dedicated to Mr. Hidetaka Miyazaki and those bring us colorful flavors through their masterpieces.

Chinese Girl's Mathematic Olympiad 2023, Problem 8 is a combinatorial gem built on the Erdős–Szekeres theorem.

Asia East Continent Final 2024, Problem I is built on a corollary of the JCDCGGG paper, which is exactly the hidden point set of a staircase polygon.

Random Pieces

56 Interesting Problems from Andrew Stankevich Contest [Chinese]. This is the problems selected by me from ASC during the past 20 years with my personal solution.

Report of CIL course project. This report illustrates how to significantly improve your transformer performance via a very simple but novel data augmentation strategy.