Blog
Findings, know-how, essays, and the occasional rant.
Software and systems, cognitive science and AI, and older posts in Chinese from my competitive programming years.
C++ | How to Safely Initialize std::mt19937
Analyzes the randomness weaknesses of seeding std::mt19937 with std::random_device and the default std::seed_seq, and shows how to initialize it correctly using /dev/urandom.
Sperner's Theorem
A full proof of Sperner's theorem: an antichain of subsets of an n-element set has at most C(n, ⌊n/2⌋) members.
Where the Entropy for /dev/random and /dev/urandom in WSL Comes From
Traces the entropy behind getrandom, /dev/random, and /dev/urandom in WSL to Windows' BCryptGenRandom rather than to the Linux kernel.
Sharing: PDF Edition of The Hitchhiker's Guide to the Galaxy
Sharing mirror, jsDelivr, and Internet Archive backup download links for the Chinese and English PDF editions of The Hitchhiker's Guide to the Galaxy.
Physics Mind Maps
A collection of high school physics mind maps covering 20 topics, from kinematics and force analysis to Newton's laws and circular motion, each with a clickable full-size image.
Essay-Writing Lecture Notes
High school Chinese essay-writing lecture notes on reading the prompt and establishing the thesis, reading the task and source material, and structural thinking methods such as parallel, progressive, and contrast-unity structures.
Classical Chinese Lecture Notes: Parsing and Translation
High school classical Chinese lecture notes covering common cues for sentence punctuation, how to check cultural-knowledge multiple choice questions, techniques for comprehension/judgment multiple choice questions, and a seven-step method for translating classical Chinese.
Classical Chinese Lecture Notes: Words and Syntax
High school classical Chinese lecture notes on content words vs. function words, flexible word usage (causative, putative, and benefactive), elliptical sentences, and four inverted sentence patterns, with classic examples.
Using the <template> Tag to Hide Content Blogger Inserts
A method that wraps a fake </body> marker in a <template> tag to get around Blogger's block on nested comments, hiding its auto-inserted content.
Editorial | CF930 / Codeforces Round 468 (Div. 1)
Editorial for a virtual-contest run of Codeforces Round 468 (Div. 1): statements, approach, and takeaways for problems A through E.
Editorial | CF986 / Codeforces Round 485 (Div. 1)
Editorial for a virtual-contest run of Codeforces Round 485 (Div. 1), covering the approach and solution for problems A through F.
A Possible Cause of the [WinError 5] Error When Running pip install --upgrade
Records a debugging session for a WinError 5 access-denied error during pip install --upgrade cffi, traced to a running Python script holding the file being updated.