Rewrite the fib method in Listing 18.2 using iterations. To compute fib(n) without recursion, you need to obtain fib(n - 2) and fib(n - 1) first. Let f0 and f1 denote the two previous Fibonacci numbers. The current Fibonacci number would then be f0 + f1. The algorithm can be described as follows:

Write a test program that prompts the user to enter an index and displays its Fibonacci number.

Listing

f0 = 0; // For fib(0) f1 = 1; // For fib(1) for (int i = 1; i