Posts

CSP September 2020

第 20 次 CCF 计算机软件能力认证 检测点查询 问题重述 给定一个点集 $S \subset \mathbb{R}^2$，再给定一个点 $p \in \mathbb{R}^2$， 求 $S$ 中到
Last updated on Oct 5, 2020 5 min read

CCPC 2020 Online

CCPC 2020 Online Graph Theory Class 问题重述 一个完全图，点的编号是 $1$ 到 $n$，$u$ 和 $v$ 之间的边权是 $lcm(u, v)$，求其 MST。 题解 不会啊，这题真的能做吗，为什么过了几百
Last updated on Sep 24, 2020 3 min read

Different Ways to Initialize an Array, and their Performance

Discuss minor performance issues introduced by array initialization in competitive programming.
Last updated on Jul 22, 2020 8 min read

A Guide to Undefined Behavior in C and C++

This is a Chinese translation of the original article on John Regehr’s blog.
Last updated on Jan 12, 2020 23 min read

Time complexity problem

Another stupid problem can lead to some thoughts.
Last updated on Sep 13, 2019 4 min read

Problem F, CF Round #536 (Div. 2)

Solution of Lunar New Year and a Recursive Sequence
Last updated on Jun 28, 2019 2 min read

Analysis of Undefined Behaviors from an Examination

Even a stupid problem can lead to some thoughts.
Last updated on Oct 5, 2020 10 min read

What Every C Programmer Should Know About Undefined Behavior #3/3

This is a Chinese translation of the original article on LLVM blog.
Last updated on Jul 10, 2020 10 min read

What Every C Programmer Should Know About Undefined Behavior #2/3

This is a Chinese translation of the original article on LLVM blog.
Last updated on Jun 28, 2019 8 min read

What Every C Programmer Should Know About Undefined Behavior #1/3

This is a Chinese translation of the original article on LLVM blog.
Last updated on Jun 28, 2019 7 min read