编写一个磁盘调度程序，模拟操作系统对磁盘的调度。

　可以随机输入磁道请求序列，当前磁头位置和磁头移动方向，支持先来先服务、最短寻道时间优先、扫描、循环扫描调度算法，能够输出磁头移动经过的磁道序列。

输入：



磁盘调度算法



　　　　当前磁头位置



　　　　磁头移动方向



　　　　磁道请求序列（磁道1,磁道2,磁道3,...)



　　　　其中：



　　　　(1) 调度算法选项为：



1 先来先服务



2 最短寻道时间优先



3 扫描法(SCAN)



4 循环扫描法(C-SCAN)



　　　　(2) 磁头移动方向选项为：



　　　　　　　　1 向磁头号增大方向移动



　　　　　　　　0 向磁头号减小方向移动



输出：



磁头移动经过的磁道序列（磁道1，磁道2，磁道3）



磁头移动经过的总磁道数-Write a disk scheduling program to simulate the operating system scheduler to disk. You can track random input sequence of requests, head position and head movement direction of the current, first-come first-serve support, the shortest seek time priority, scanning, cyclic scan scheduling algorithm, capable of outputting head is moved through a sequence of tracks. Input: disk scheduling algorithm which is currently the head position of the head moving direction of the track sequence of requests (Track 1, Track 2, Track 3, ...) in which: (1) scheduling algorithm options are: 1　 first come, first served 2 - shortest seek preferred 3　 scanning (sCAN) 4　 cyclic scan method (C-sCAN) (2) head movement direction options: 1　 to head number increasing direction 0　 mobile mobile number decreasing direction is output to the head: the head is moved through a sequence of tracks (track 1, track 2, track 3) the total number of tracks head movement through