Consider the following method. Give a recurrence formula for the running time of this code. Then
use the master theorem to provide the time complexity analysis.
a) T' (n) = 21(n/2) + n
b) T (n) = T(n — 1) + n
c) T (n) = 3T (n/3) + n
d) T (n) = T(n - 2) + n?