What is CP？

CP is short for Competitive Programming. Unlike software engineering, in CP, we need to implement certain algorithms and data structures within the given time, in order to solve some particular problems which may not have practical meanings.

Why CP?

Every one has their own reason for participating in CP. Personally, I think CP is a "thinking gymnastics".

How to do CP?

There are many online CP platforms, e.g., Codeforces, AtCoder, USACO, Leetcode, Luogu, etc. There are also many platforms offering online judge, including POJ, HDOJ, Kattis, UVA, SPOJ, LibreOJ, etc.