Exercise $2\mathrm{.}28.$

This question has two parts.

$($a$)$ Design the gcdTR tail recursive method, which receives two integers and returns the

greatest common divisor between the two. Euclid$$s algorithm is the basis for this approach

and is a tail recursive algorithm by design.

$($b$)$ Design the gcdLoop method that solves the problem using a loop.

If you write tests for one of these methods, you should be able to propagate it through the

other, so write plenty!