Question: [38] Consider the stronger offline deterministic Turing machine model with a two-way read-only input tape. Given an l l matrix A, with l =
[38] Consider the stronger offline deterministic Turing machine model with a two-way read-only input tape. Given an l × l matrix A, with l = n/ log n and element size O(log n), arranged in row-major order on the two-way (one-dimensional) input tape,
(a) Show that one can transpose A (that is, write AT on a work tape in row-major form) in O(n log n) time on such a Turing machine with two work tapes.
(b) Show that it requires Ω(n3/2/
√log n) time on such a Turing machine with one work tape to transpose A.
(c) From Items
(a) and (b), obtain a lower bound on simulating two work tapes by one work tape for the machines.
Comments. Source: [M. Dietzfelbinger, W. Maass, and G. Schnitger, Theoret. Comput. Sci., 82:1(1991), 113–129].
Step by Step Solution
There are 3 Steps involved in it
Get step-by-step solutions from verified subject matter experts
