//FibonacciSequence.java

import java.util.Scanner;

public class FibonacciSequence
{
    /* Output the Fibonacci sequence step-by-step.
       Fibonacci sequence starts as:
       0 1 1 2 3 5 8 13 21 ... in which the first
       two numbers are 0 and 1 and each additional
       number is the sum of the previous two numbers
    */
    public static void computeFibonacci
    (
        int fibNum1,
        int fibNum2,
        int runCnt
    )
    {
        System.out.println
        (
            fibNum1
            + " + "
            + fibNum2
            + " = " 
            + (fibNum1 + fibNum2)
        );

        if (runCnt <= 1) // Base case: Ran for user specified
        {
            // number of steps, do nothing
        }
        else // Recursive case: compute next value
        {
            computeFibonacci(fibNum2, fibNum1 + fibNum2, runCnt - 1);
        }
    }

    public static void main(String[] args)
    {
        Scanner scnr = new Scanner(System.in);
        int runFor; // User specified number of values computed

        // Output program description
        System.out.println
        (
            "This program outputs the\n"
            + "Fibonacci sequence step-by-step,\n"
            + "starting after the first 0 and 1.\n"
        );

        // Prompt user for number of values to compute
        System.out.print("How many steps would you like? ");
        runFor = scnr.nextInt();

        // Output first two Fibonacci values, call recursive function
        System.out.println("0\n1");
        computeFibonacci(0, 1, runFor);
    }
}