"The study of computational complexity teaches us that some problems are inherently difficult, no matter how clever our algorithms are."
计算复杂性的研究告诉我们，有些问题本质上是困难的，无论我们的算法多么聪明。
Every life is in many days, day after day. We walk through ourselves, meeting robbers, ghosts, giants, old men, young men, wives, widows, brothers-in-love, but always meeting ourselves.
激发生命，让生命自由发展，这是教育者的首要任务。
