You cannot teach a man anything, you can only help him to find it for himself.
你不可能教一个人任何知识, 因为你只能帮助他自己去找他想学的。
当你为爱情而钓鱼时,要用你的心当作饵,而不是用你的脑筋。
There is no trap so deadly as the trap you set for yourself.
The concept of NP-completeness has provided a powerful tool for understanding the complexity of problems.