Archives
Chronological index of published notes.
2026
GateKeeper Mode：在 AI 改代码之前，先建质量门禁
GateKeeper Mode: Building a Quality Gate Before Letting AI Touch Your Code
AGENTS.md Practice Guide — Map, Commands, and Verification Loops for AI Coding Agents
Number Theory #4: Primality, Factorisation & Residues (Miller-Rabin, Pollard Rho, Tonelli-Shanks)
Number Theory #4: Min_25 Sieve and Du Jiao Sieve
Number Theory #3.1: Sieve Problems — Coin System DP via Sieve
Number Theory #3: From Eratosthenes to Möbius Inclusion-Exclusion
Number Theory #2: Multiplicative Functions, Möbius Inversion & Dirichlet Convolution
Number Theory #2-ex: Möbius Techniques
Number Theory #2-ex: Möbius Practice — LCM Sums, Divisor-Count, Omega Numbers
Number Theory #1.1: Divisibility Blocking (Floor-Division Decomposition)
Number Theory #1: Elementary Number Theory — GCD, LCM, Euler, CRT
Number Theory #0: Common Formulae — Legendre's Formula & Divisor Convolutions
Matrix #4: Matrix Problems — Fibonacci Subarray Sums, Gaussian Elimination & Expected Value
Matrix #3: Linear Basis (XOR Basis) & Simplex Method
Matrix #2: Gaussian Elimination — Real, Mod, Mod-2, Incremental
Matrix #1: Matrix Fast Power — Linear Recurrence, DP Semirings & Kitamasa
Combinatorics: Order Theory — Chromatic Polynomials, Chordal Graphs, Order Polynomials, Dilworth & Hall
Combinatorics #3.2: More Operations on Formal Power Series
Combinatorics #3.1: Ordinary Generating Functions
Combinatorics #2.2: Primitive Roots, Discrete Logarithm, NTT, Divide-and-Conquer NTT
Combinatorics #2.1: FFT and Lagrange Interpolation
Combinatorics #2-ex2: Cyclic Convolution
Combinatorics #2-ex1: Difference (Correlation) Convolution
Combinatorics D1: Diophantine Equations
Combinatorics #1.1: Permutations and Combinations
Combinatorics #1.2：容斥原理、不定方程、错排
Combinatorics #1.2: Inclusion-Exclusion, Bounded Diophantine Equations, and Derangements
Combinatorics #0.1: 计数中常用的结论
Combinatorics #0: Common Formulae & Conclusions