direct graphs

• 有向图

direct graphs的用法和样例：

例句

1. And the coefficients of eigen-polynomial expressions were closely related to the circular sets of a directional graph.
   而特征多项式的系数与有向图的圆族有着密切的关系。
2. In a directed graph, the decision variables of the shortest path computation must be determined by a constraint that is called Kirchoff's constraint.
   摘要已知一个有向图，求解两点间的最短路径的决策变量满足基尔霍夫约束关系。