The document outlines a Java program that computes the Fibonacci series using both iterative and recursive algorithms. It defines a class 'fib' with methods to calculate Fibonacci numbers and handles input parameters through command line arguments, including error checking for invalid inputs. The program demonstrates the functionality by printing Fibonacci numbers up to a given 'n' using both methods.

1. 1Write a Java program that calculates and displays the Fibonacciseries, defined by the recursive
formula
F(n) = F(n-1) + F(n-2).
F(0) and F(1) are given on the command line.Define and use a class Fib with the following
structure:
public class Fib {
// constructorpublic Fib(int f0, int f1){.....}
// computes F(n) using an ***iterative*** algorithm, where F(n) = F(n-1) +
F(n-2) is the recursive definition.
// use instance variables that store F(0) and F(1).
// check parameter and throw exception if n < 0. Don't worry about
arithmetic overflow.
public int f(int n) {....}
// computes F(n) using the ***recursive*** algorithm, where F(n) = F(n-1)
+ F(n-2) is the recursive definition.
// use instance variables that store F(0) and F(1).// check parameter and throw exception if n < 0.
Don't worry about
arithmetic overflow.
public int fRec(int n) {....}
public static void main(String[] args){
// get numbers F(0) and F(1) from args[0] and args[1].// use either the Scanner class or
Integer.parseInt(args[...])// you must handle possible exceptions !....
// get n from args[2]:....
// create a Fib object with params F(0) and F(1)....
// calculate F(0), ..., F(n) and display them with
System.out.println(...) using
// the iterative methode f(i)....
// calculate F(0), ..., F(n) and display them with
System.out.println(...) using
// the recursive methode fRec(i)....
}
// instance variables store F(0) and F(1):....
};
Write javadoc comments for the Fib class.

2. Solution
// Fib.java
/**
* This class provide iterative as well as recursive mode of
* finding nth value of fibonaci series
*
* To run this program please run like java Fib 1 1 10
*
* This means f(0) = 1, f(1) = 1 and you want to compute series for 10 numbers
*
* @author Anonymous
*
*/
public class Fib {
public Fib(int first, int second)
{
f0 = first;
f1 = second;
}
static int f0;
static int f1;
public static int f(int n) throws Exception
{
if (n < 0)
{
throw new Exception ("invalid value: n should be greater than equal to 0");
}
if (n == 0) return f0;
if (n == 1) return f1;
int prev = f1;
int prevprev = f0;

3. int result = 0;
for (int i = 2 ; i <= n; i++)
{
result = prev + prevprev;
prevprev = prev;
prev = result;
}
return result;
}
public static int fRec(int n) throws Exception
{
if (n < 0)
{
throw new Exception ("invalid value: n should be greater than equal to 0");
}
if ( n == 0)
{
return f0;
}
if (n == 1)
{
return f1;
}
return fRec(n-1) + fRec(n-2);
}
public static void main(String[] args) throws Exception{
int first = 0;
int second = 0;
int n = 0;
try
{
first = Integer.parseInt(args[0]);
second = Integer.parseInt(args[1]);
n = Integer.parseInt(args[2]);

4. }
catch (Exception e)
{
System.out.println("Please enter integer number only: " + e);
throw e;
}
Fib fib = new Fib(first, second);`
System.out.println("Printing using iterative method");
for (int i = 0; i <= n; i++)
{
System.out.println(f(i));
}
System.out.println("Printing using recursive method");
for (int i = 0; i <= n; i++)
{
System.out.println(fRec(i));
}
}
};
/*
Sample run
java 1 1 30
Printing using iterative method
1
1
2
3
5
8
13
21
34
55

5. 89
144
233
377
610
987
1597
2584
4181
6765
10946
17711
28657
46368
75025
121393
196418
317811
514229
832040
1346269
Printing using recursive method
1
1
2
3
5
8
13
21
34
55
89
144
233
377

6. 610
987
1597
2584
4181
6765
10946
17711
28657
46368
75025
121393
196418
317811
514229
832040
1346269
*/