说明：  文件包括：1.计算平均最短路径；2.计算每个顶点相邻节点的平均度；3.计算每个节点的邻近中心度；4.计算节点的介数（slow）；5.计算节点的介数（faster）；6.计算每条边的介数值；7.快速迪杰斯特拉算法；8.经典迪杰斯特拉算法。
(1.the average shortest path in the graph 2.the average degree of neighboring nodes for every vertex 3.computes the closeness centrality for all vertices 4.node betweenness, (number of shortest paths definition) 5.a faster node betweenness algorithm 6.edge betweenness, (number of shortest paths definition) 7.simple Dijkstra, does not remember the path 8.Dijkstra which also returns the shortest paths.)