Program for Fibonacci numbers

 

Program for Fibonacci numbers

//Fibonacci Series using Recursion
class fibonacci
{
    static int fib(int n)
    {
    if (n <= 1)
       return n;
    return fib(n-1) + fib(n-2);
    }
      
    public static void main (String args[])
    {
    int n = 9;
    System.out.println(fib(n));
    }
}
/* This code is contributed by Rajat Mishra */

// Fibonacci Series using Dynamic Programming
class fibonacci
{
   static int fib(int n)
    {
        /* Declare an array to store Fibonacci numbers. */
    int f[] = new int[n+1];
    int i;
      
    /* 0th and 1st number of the series are 0 and 1*/
    f[0] = 0;
    f[1] = 1;
     
    for (i = 2; i <= n; i++)
    {
       /* Add the previous 2 numbers in the series
         and store it */
        f[i] = f[i-1] + f[i-2];
    }
      
    return f[n];
    }
      
    public static void main (String args[])
    {
        int n = 9;
        System.out.println(fib(n));
    }
}
/* This code is contributed by Rajat Mishra */

// Java program for Fibonacci Series using Space
// Optimized Method
class fibonacci
{
    static int fib(int n)
    {
        int a = 0, b = 1, c;
        if (n == 0)
            return a;
        for (int i = 2; i <= n; i++)
        {
            c = a + b;
            a = b;
            b = c;
        }
        return b;
    }
 
    public static void main (String args[])
    {
        int n = 9;
        System.out.println(fib(n));
    }
}
 
// This code is contributed by Mihir Joshi

 http://www.geeksforgeeks.org/program-for-nth-fibonacci-number/