試題詳解

7. Assume there are four frames in main memory. Consider the following page reference string: 2, 1, 6, 4, 1, 2, 5, 3, 1, 2, 1, 6, 7, 3, 6, 1, 2, 1, 6, 3. How many page faults occur for the OPT (Optimal Page-replacement Algorithm) replacement? Notes: All frames are initially empty, so the first unique pages will all cost one fault.
(A) 7
(B) 8
(C) 9
(D) 10
(E) 11