It took me seven comparisons, because I can take advantage of the fact I know I only ever have to look at the first element of each sub-list. Those are the only things I need to compare, and when I run out of one list, I just add the rest of the list in.

进行了7次对比，因为我可以利用我知道的优势：,每次只需要比较每个子列表的第一个元素,那才是我需要进行对比的内容,当一个列表的元素处理完了,只需要将另一个列表剩下的元素直接添加进去。

麻省理工公开课 - 计算机科学及编程导论课程节选

I'll let you just grok it but you can see it's basically doing what I did over there. Setting up two indices for the two sub-list,it's just walking down, finding the smallest element, putting it into a new list. When it gets to the end of one of the lists, it skips to the next part, and only one of these two pieces will get called because only one of them is going to have things leftovers.

你们可以大体的浏览一下,但是它们基本就是我在那里所做的事情,为两个子列表设置了两个指针,指针顺着列表走下去，找到最小的元素,把它放入到一个新的列表中去,当它走到一个列表的尾部时,它会跳到下部分去,两部分中只有一个会被执行,因为只有一个会有元素剩余。

麻省理工公开课 - 计算机科学及编程导论课程节选

You can also assign to a list, or to an element of a list. So ivy sub 1, f -15 or example, could be assigned minus 15, and that will actually mutate the list.

此外你还可以给一个数组，或者数组内部的元素赋值,比如ivy。sub，可以被赋值为，这确实改变了数组。

麻省理工公开课 - 计算机科学及编程导论课程节选