The computer is incredibly fast, accurate, and stupid. Man is unbelievably slow, inaccurate, and brilliant. The marriage of the two is a force beyond calculation.

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

如果你问一个经济学家，什么驱动着经济增长，他定会提出一些慎重的意见作为答复——农业机械化、大规模生产，诸如此类。但问题是，我们的社会组织不是靠这些事情建立起来的。

假设生活会非常艰难，然后问自己能否承受。如果答案是肯定的，你就赢了。