所谓拓扑排序是指将顶点按照拓扑次序排列。有几种简单的算法可以求出一个图的拓扑次序。一种算法的思想如下：



（1）在有向图中查找一个没有后继（或前驱）的顶点并添加到顶点表中。



（2）从图中删除该顶点和所有以该顶点为头（尾）的弧。

-The so-called topological sorting refers to the vertex order in accordance with the topology. There are several simple algorithm can find the order of a topological map. The idea of an algorithm as follows: (1) in the directed graph to find a follow-up (or precursor) is added to the vertex and vertex table. (2) from the plan to remove all of the vertex and the vertex for the head (tail) of the arc.