CCPC 2024 哈尔滨区域赛（Harbin Regional）部分题目的题解：
A. Build a Computer
B. Concave Hull
D. A Simple String Problem
E. Marble Race
G. Welcome to Join the Online Meeting!
I. A Brand New Geometric Problem
J. New Energy Vehicle
K. Farm Management
L. A Game On Tree

ICPC 2023 澳门区域赛（Macau Regional）（Codeforces Gym 104891）部分题目的题解：
A. (-1,1)-Sumplete
D. Graph of Maximum Degree 3
F. Land Trade