The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.

You don’t have to be great to start, but you have to start to be great.

作家的职责是讲述可怕的真相，而读者的职责是从中学习。

If not me, who? If not now, when?

希望不是一种感觉；它是一种可行的事情。