Okay so exchange numbers; okay good half of that problem is gone now we have just these two left.

好，交换数字,好，问题解决一半了,只剩你们两个了。

哈佛公开课 - 计算机科学课程节选

You actually need to kind of do this and then you can swap these two numbers but it requires 50 percent more memory.

你实际上需要这样做,然后才能交换两个数字,但是它需要多50%的内存。

哈佛公开课 - 计算机科学课程节选