假设磁头当前位于第 105 道,
正在向磁道序号增加的方向移动。现有一个磁道访问的请求序列为 55,189,67,191,34,122,9,178,87,125,18,136,157,48,115,73。采用 SCAN(电梯)调度算法得到的磁道访问序列是
115,122,125,136,157,178,189,191,87,73,67,55,48,34,18,9
115,122,125,136,157,178,189,191,9,18,34,48,55,67,73,87
87,73,67,55,48,34,18,9,115,122,125,136,157,178,189,191
87,73,67,55,48,34,18,9,191,189,178,157,136,125,122,115
答案
115,122,125,136,157,178,189,191,87,73,67,55,48,34,18,9
解析
[电梯算法]:
“正在向磁道序号xx的方向移动”
xx决定方向,持续移动,直到尽头,然后返回[当前]位置,向反方向移动