The most beautiful things in life are not things, but moments.
The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.
向人求助之时应该去求真正胸襟开阔的人;帮助别人时要帮助真正需要帮助的人。
避免痛苦的唯一方法就是不要有足够的闲暇去思考你是否快乐。