最小生成树的数据结构解法，若要在n个城市之间建设通信网络，只需要架设n－1条线路即可。如何以最低的经济代价建设这个通信网-minimum spanning tree data structure solution, if a n cities between building communications networks needed to put up only n-1 line can be. How the lowest economic cost of building the communications network