说明：  在一个半径为R的监测区域，随机分布有M个节点，每个节点的感应半径为r，请完成： （1）建立节点的位置信息文件 （2）建立网络的拓扑信息文件 （3）输出最佳路由即最小生成树
(Radius of R in a monitoring region, a random distribution of M nodes, each node of the sensor radius r, please complete: (1) to establish the location of the node information file (2) the establishment of the network topology information file (3) output the best route that is minimum spanning tree)