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.
"A book is a friend that never lets you down."
Power is not a means; it is an end. One does not establish a dictatorship in order to safeguard a revolution; one makes the revolution in order to establish the dictatorship.
量子计算的发展将需要对物理学和计算机科学的深刻理解。