GATE | Gate IT 2007 | Question 80

The head of a hard disk serves requests following the shortest seek time first (SSTF) policy. The head is initially positioned at track number 180.

What is the maximum cardinality of the request set, so that the head changes its direction after servicing every request if the total number of tracks are 2048 and the head can start from any track?
(A) 9
(B) 10
(C) 11
(D) 12


Answer: (C)

Explanation: Distance of SSTF changing – >

1	3	7	15	31	63	127	255	511	1023	2047
1	2	3	4	5	6	7	8	9	10	11

Head is changing it’s direction after servicing every request. Maximum Cardinality is thus 11

 180->181->178->185->170->201->138->265->10

Quiz of this Question

My Personal Notes arrow_drop_up

Save