#Counting

2 posts

Combinatorics #0.1 April 20, 2026 9 min read

计数中常用的结论

常见计数结论、Lucas 定理、不定方程解计数、平面分拆、DAG 路径计数、多项式平移、XOR 均匀性与若干竞赛常用结论。

#math #combinatorics #counting #lucas #partition

Combinatorics #1.2 April 20, 2026 2 min read

Inclusion-Exclusion, Bounded Diophantine Equations, and Derangements

Inclusion-exclusion in set and operator form, equal-count subproblems, bounded Diophantine counting, derangements, Stirling numbers, and selected contest problems.

#math #combinatorics #inclusion-exclusion #derangements #diophantine