Figure out how you can make it move a little to the left, a little to the right, up and down and then repeat in some kind of looping structure.

就是找出办法让它向左移动一小步，向右移动一小步，向上一小步，向下一小步,像这样不断重复。

哈佛公开课 - 计算机科学课程节选

And because you can't really know, it's difficult to make the right kinds of plans.

又因为你无法知道，要作正确的规划就困难重重。

耶鲁公开课 - 死亡课程节选