Chapter 18 Exercise 7, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

18. 7 (Fibonacci series)
Modify Listing 18.2, ComputeFibonacci.java, so that the
program finds the number of times the fib method is called.

import java.util.Scanner;

public class Exercise_07 {

    static long count;

    public static void main(String args[]) {

        System.out.print("Enter an index for the Fibonacci number: ");
        int index = new Scanner(System.in).nextInt();

        System.out.println(
                "Fibonacci number at index " + index + " is " + fib(index));

        System.out.println("The fib method was called " + count + " times");
    }

    public static long fib(long index) {
        count++;
        if (index == 0) // Base case
            return 0;
        else if (index == 1) // Base case
            return 1;
        else  // Reduction and recursive calls
            return fib(index - 1) + fib(index - 2);
    }
}