2026
11 posts
- →fabonacci
This post is currently available in Chinese only. The English version will be added later.
- →Xidian University 2026 Entrance Examination Math Solutions
Step-by-step solutions and mathematical derivations for the 2026 Xidian University entrance exam (fill-in-the-blanks and analytical problems).
- →A Brief Introduction to Deep Learning
Following a conceptual progression: network structure, gradient descent, embedding vectors, Transformer, attention mechanisms, and MLP fact storage.
- →Raft Summary
A study note on Raft covering replicated state machines, elections, log replication, safety, cluster membership changes, and snapshots.
- →AtCoder Solutions 1
March-June 2024, primarily based on original solution records, including ABC 340 F, 341 D, 346 D/E/F, 356 D/E/F.
- →AtCoder Solutions 2
April~July 2024, primarily based on original solution records, including ABC 348 E/F, 350 D/E, 351 D/E/F, 357 D/E/F, 358 C/E/G, 360 E.
- →Codeforces Solutions 1
Solutions from Jan-Jul 2024, focusing on construction, bit operations, and greedy problems from Codeforces.
- →Codeforces Solutions 2
Solutions from Dec 2023 to Jul 2024, covering prefix sums, strings, and transformation-oriented Codeforces problems.
- →Codeforces Solutions 3
Solutions from Jan-Sep 2024, focusing on number theory, game theory, combinatorics, and EDU problems from Codeforces.
- →Invitational and Misc Solutions
Primarily based on original solution records, including Zhengzhou Invitational, Kunming Invitational, HDU 2973, and Luogu B3645.
- →Nowcoder Solutions
December 2023 to August 2024, primarily based on original solution records, covering bookmarked winter contests, weekly contests, and multi-school problems.
2025
9 posts
- →Tips to improve concentration
Mindfulness, cognitive training, and a healthy lifestyle may help sharpen your focus.
- →Probabilistic Data Structures in Redis: HyperLogLog and Bloom Filters
A deep dive into the mathematical principles behind HyperLogLog and its Redis implementation
- →Redis (I): Overview
Redis-related notes previously written in Apple Notes.
- →MySQL (II): Transactions and MVCC
Notes on transactions and MVCC.
- →MySQL (III): Logs and Locking Mechanisms
Earlier MySQL notes.
- →When Problem-Setting Syndrome Strikes, Start with the Strange Core
Based on the original "Problem-Setting Syndrome Struck" notes, preserving the "Magic Bag" problem, derivation, code, and extension directions.
- →Java Concurrency
Covers JMM, locks, atomic classes, ThreadLocal, thread pools, and more.
- →MySQL (I): Page Structure, Indexes, and B+ Trees
Notes covering fundamentals, indexes, B+ trees, and execution plans.
- →Java Abstract Boundaries: Collections, IO, Reflection, Proxy, and SPI
Based on original Java notes, preserving the original organization of Collections, IO, Reflection, Proxy, and SPI.
2024
5 posts
- →Why Polynomial Algorithms Matter in Competitive Programming
From convolution, point-value representation, FFT/NTT to formal power series - understanding what this polynomial toolkit is really solving.
- →My Intro to Generating Functions: Let Coefficients Be Answers
Built from the original notes, restoring ordinary generating functions, exponential generating functions, modeling intuition, and several typical problems.
- →From Convolution to Inversion: What Mobius Inversion Does
Based on original number theory notes, covering Dirichlet convolution, Möbius function, inversion techniques, and common identities.
- →A Framework for Judging Game Theory in Contests
Based on original game theory notes, supplementing the judgment framework, Bash/Nim, Misere games, Fibonacci game, Wythoff's game, and SG function.
- →Search Is Not Brute Force: DFS, BFS, and DP
Built from original search problem sets and solution notes, organizing DFS, BFS, pruning, shortest paths, and state-space search.
2023
2 posts
- →Sieve Methods Beyond Primes: A Unified View of Linear Sieve
Based on original number theory notes, covering prime sieves, Euler's totient function, and Wilson's theorem.
- →From Divisibility to Congruence: Number Theory Basics
Based on original number theory notes, covering gcd, lcm, Bezout, exgcd, fast power, modular inverse, and CRT.