Here is a simple recursive function to compute the Fibonacci sequence:

This algorithm turns out to be very slow, calling Fibr a total of Fib(n) times. Contrast this with the following iterative algorithm:

Function Fibi executes the for loop n - 2 times.

(a) Which version is easier to understand? Why?

(b) Explain why Fibr is so much slower than Fibi.

// Recursive Fibonacci generator static long fibr (int n) { // fibr (91) is the largest value that fits in a long assert (n> 0) && (n