I want to show you how easy it is to change the code. But, notice, once I've added this I actually have a problem. This is now an under-constrained problem. I have more unknowns than I have equations.

我加上这个条件后,我马上面临一个问题了,这就是现在是一个非约束性问题了,我的未知数比方程数多,你从代数中可以知道。

麻省理工公开课 - 计算机科学及编程导论课程节选

Because in an under-constrained problem there could be multiple solutions. So suppose I want to capture all of them or print all of them out.

因为在一个非约束性问题中,可能会有多组答案,所以假设我想把它们,全部获取或者全部输出。

麻省理工公开课 - 计算机科学及编程导论课程节选