若任务的运行方式为非抢占式的，即任务开始后不可中断，需要连续运行pi时间，请给出一个调度算法，尽量使所有任务的平均结束时间最小。-The task of running a non-preemptive, after the start of the task can not be interrupted, continuous operation pi time, please give a scheduling algorithm, as far as possible so that the minimum average end time of all tasks.