假设磁头当前位于第 107 道,
正在向磁道号增加的方向移动。现有一个磁道访问的请求序列为 58,191,69,193,36,124,11,180,89,127,20,138,159,50,117,75。采用 SCAN(电梯)调度算法得到的磁道访问序列是
117,124,127,138,159,180,191,193,89,75,69,57,50,36,20,11
117,124,127,138,159,180,191,193,11,20,36,50,57,69,75,89
89,75,69,57,50,36,20,11,117,124,127,138,159,180,191,193
89,75,69,57,50,36,20,11,193,191,180,159,138,127,124,117
答案
117,124,127,138,159,180,191,193,89,75,69,57,50,36,20,11
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