说明：  功能：该程序用于仿真时间同步算法双向不等时间同步方法与无时漂往返校时方法（RTT）。输入：节点间距离、钟漂。输出：两幅同步误差比对图。
(Features: The program for the simulation of two-way time synchronization algorithm for time synchronization methods ranging from no time when the drift from school method (RTT). Input: the distance between nodes, clock drift. Output: two synchronization errors of the map.)