3 So here what I'm doing is 17 divided by 13, but because of this parenthetical, , -- because of that parenthetical -- that has nothing to do with math; -- this is a programming language thing -- that is a casting operation.

所以这里我要做的是用17除以，但因为这样的题外话，因为那样的题外话-,还是没有做完这个数学题;,这是一个编程语言的东西-,那是一个计算操作。

哈佛公开课 - 计算机科学课程节选

I was just finding very tunnel vision-like, the smallest elements at that moment in time which means I don't know anything about the other elements other than they are not the smallest and so no matter what with Selection Sort I had to repeat this again and again and again and if you do out the math it's roughly N squared steps in the worst case as well.

我只有一个狭窄的视野，只知道某时刻的最小元素,就意味着我并不知道其他元素的任何情况,只知道它们不是最小的,所以不管怎样，在选择排序中,我就得一遍一遍地重复选择过程,在最坏情况下,大概需要N的平方次比较。

哈佛公开课 - 计算机科学课程节选