用C语言编写的 如果以无向网表示n个城市之间的交通网络建设规划，顶点表示城市，边上的权表示该线路的造价，试设计一个方案，使这个交通网的总造价最小-Using C language if no express n to the network traffic between cities network construction planning, Vertex city, the edge of the right to express the cost of the line and try to design a program to make the transportation network total cost of the smallest