Data structure problem

Question 3 (12 marks): Recursion & iteration The definition of the Fibonacci series is shown as follows: 0, Fibonacci(n)-1, if n-0 ifn=1 otherwise Fibonacci(n-1)+Fibonacci(n-2), A. Please write a recursive function to calculate the Fibonacci series. The recursive function should have the declaration: int fib(int n. B. Please write an iterative function to calculate the Fibonacci series. The iterative function should have the declaration: int fib(int n