It's going to run through the loop, accumulating the answers, but because I'm subtracting, x it's just going to keep making x more and more negative as it goes along, again it's off into an infinite loop.

它一直在循环，不断的累加答案，这是因为我一直在对x做减法，这使得作为负数的,变的越来越小，又进入一个无限循环了。

麻省理工公开课 - 计算机科学及编程导论课程节选