i want it without recargane

If the goal is to return the series till n then using recursion is a waste of time. Instead use an array and store the previous values. import javax.swing.JOptionPane; class Fibonnaci { public static void main(String args[] { String input = JOptionPane.showInputDialog("Enter n: "); int n = Integer.parseInt(input); int[] arr = new arr[n]; arr[0]=1; arr[1]=1; for(int i=2; i

for(int i=2; i

I tried :( Code doesn't seem to come in comments ! anyways the logic is to make use of the previous values instead of finding out the values everytime.

There is a way to do this without recursion... there is what is called a "Closed Form". This means that the nth number in this sequence can be expressed in terms of n.

Closed form: public long fib(int n) { double termA = Math.pow((1+Math.sqrt(5))/2, n); double termB = Math.pow((1-Math.sqrt(5))/2, n); double factor = 1 / Math.sqrt(5); return Math.round(factor * (termA - termB)); }

I should also note that my implementation assumes f1 = 0 and f2=1