(a) Design a recursive algorithm for computing 2n for any nonnegative integer n that is based on the definition twoto (n) =

1 if n = 0

[twoto n^2]^2 if n mod 2 = 0

2 twoto (n 1) if n mod 2 not = 0.

Your algorithm should minimize the number of required multiplications.

(b) How many multiplications are made in the computation of twoto (19)?