It's in a file called swap.C. Everything should be alphabetical so it should be toward the end of this week's packet and notice that it's almost identical except for a couple of syntax changes.

在一个叫做swap。c的文件中，对于这周末的数据包来说,所有的东西都是字母,请注意,除了几个语法改变,它几乎是一样的。

哈佛公开课 - 计算机科学课程节选