Fibonacci

gistfile1.txt

public static int fibonacci(int num){ //non-recursive fibonacci. returns the nth fibonacci number.
    double phi= (1+Math.sqrt(5))/2; 
    return((int)((Math.pow(phi,num)-Math.pow(1-phi,num))/Math.sqrt(5))); //finding fibonnaci number using formula.
  }
  public static int fibonacciRec(int num){ //recurive fibonacci. Used to demonstrate fibonacci
    if(num==1||num==2){ //stopping case. F(1)=1, F(2)=1 by definition.
      return(1);
    }
    return(fibonacciRec(num-1)+fibonacciRec(num-2)); //definition of Fibonacci sequence: F(n)=F(n-1)+F(n-2)
  }