地铁建设问题-

1）从包含各辖区的地图文件中读取辖区的名称和各辖区的直接距离

（2）根据上述读入的信息，给出一种铺设地铁线路的解决方案。使乘客可以沿地铁到达各个辖区，并使总的建设费用最小。

（3）输出应该建设的地铁路线及所需要建设的总里程信息。

-Subway construction- 1) the name of the area and the direct distance of each area (2) based on the information read into the above solution, given a laying subway lines read from the map file that contains the various jurisdictions. So that passengers can reach each area along the subway, and the minimum total construction costs. (3) The output should be the construction of subway routes and the total mileage of the need to build.