我如何检查是否有向图是无环？而且怎么叫算法？我想AP preciate一个参考。

How do I check if a directed graph is acyclic? And how is the algorithm called? I would appreciate a reference.

推荐答案

我会尝试排序拓扑，如果​​你不能，那么它有个周期。

I would try to sort the graph topologically, and if you can't, then it has cycles.