初始化一个有VertexNum个顶点但没有边的图
typedef int Vertex;
MGraph CreateGraph(int VertexNum)
{
Vertex V,W;
MGraph Graph;
Graph = (MGraph)malloc(sizeof(struct GNode));
Graph->Nv=VertexNum;
Graph->Ne=0;
for (V=0;V<Graph->Nv;V++)
for (W=0;W<Graph->Nv,W++)
Graph->G[V][W]=0; // 有向图设为inf
return Graph;
}
