A subgraph is a subset of the nodes and edges within a graph子图是图中结点和边线的子集。 A graph is directed( a digraph) if each edge links two lodes together only in one direction如果每条边线仅在 个方向上将两个结点连接起来,则该图为有向图。 a graph is weighted if each edge has some value associated with it如果每条边线都有一些相关的值,则该图为加 权图。4 A subgraph is a subset of the nodes and edges within a graph. 子图是图中结点和边线的子集。 A graph is directed( a digraph ) if each edge links two nodes together only in one direction. 如果每条边线仅在 一个方向上将两个结点连接起来，则该图为有向图。 A graph is weighted if each edge has some value associated with it. 如果每条边线都有一些相关的值，则该图为加 权图