一个问题如果在计算机上可以快速解决，那么它属于P类问题；如果一个解可以快速验证，那么它属于NP类问题。
A problem is in P if it can be solved quickly by a computer, and in NP if a solution can be verified quickly.
Quality starts from the soil. Healthy earth grows healthy fruits.
Life is about making an impact, not making an income.
文学的目的是将血液转化为墨水。