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-The data structure of the minimum spanning tree solution, To the construction of communications networks, and only need to set up the n-1 lines can be between the n cities. The communication network at the lowest economic cost of construction