A problem is in P if it can be solved quickly by a computer, and in NP if a solution can be verified quickly.
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。
The mystery of love is greater than the mystery of death.
"Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding."
思考就是将自己局限于一个单一的思想。