实现无线传感器网络leach协议。簇头随机分布在网络中，节点产生随机数，并判断是否大于阈值，如果大于阈值则作为簇头。每隔一定时间簇头选择一次。-Wireless sensor networks leach agreement. Cluster head randomly distributed in the network, the node generates a random number, and to determine whether greater than the threshol