优化是在给定约束条件下做出最佳决策的艺术。

There's a tendency to think that our present politicians are much worse than we had in the past.But we tend to forget how awful our politicians were in the past.

计算机科学中的挑战不仅仅是解决问题，而是找到正确的问题来解决。

"I like to draw ordinary people doing ordinary things."