计算无向图中，从某一点出发到其余各点距离之和的最小值。应用Dijkstra算法完成。输入格式为，先输入两个数字N和M，N为顶点个数；之后输入M行数据，每行数据为两个顶点号以及顶点之间的距离。-Calculating an undirected graph, starting from a point to the rest of the points and the minimum distance. Application of Dijkstra' s algorithm is complete. The input format is, first enter two numbers N and M, N is the number of vertices　then enter the M rows of data, each row of data for the two vertices number and the distance between the vertices.