資料結構及演算法

It is impossible to give the topological ordering for a direct cyclic graph.

The shortest paths from a single source in a weighted DAG can be found using an $O(V+E)$-time greedy algorithm based on topological ordering, where $V$ is the number of vertices and $E$ is the number of edges.

In a DAG, if there is a path from vertex $u$ to vertex $v$, then $v$ appears after $u$ in topological ordering.

The longest paths from a single source in a weighted DAG can be found using an $O(V+E)$-time greedy algorithm based on topological ordering, where $V$ is the number of vertices and $E$ is the number of edges.