The end test-- and I've got the wrong glasses on but it's up here, where I'm looking to see, is last minus first less than or equal to 2?

最后一次比较，我看错了,在上面，last减去first是不是小于2呢？,好的，既然我得到了一个？

麻省理工公开课 - 计算机科学及编程导论课程节选