/* File: FibArray.java - March 2011 */
package l04;

/**
 * Compute and display the Fibonacci number of the input argument
 * using an iterative algorithm, and storing intermediate results
 * in an array. This mimics how the computations would be
 * done 'on paper'. Its only disadvantage is that the storage use
 * in the fib method is not actually needed as the other implementations
 * demonstrate. Long values are returned so that quite large inputs 
 * (e.g. 100) are possible.
 *
 * Sample usage: java l04.FibArray 5
 *
 * @author Michael Albert
 *
 */

public class FibArray{

   public static void main(String[] args) {

      int n = Integer.parseInt(args[0]);
      System.out.println("Fib(" + n + ") = " + fib(n));

   }

   public static long fib(int n) {

      if (n <= 1) return 1;
      long[] fib = new long[n+1];
      fib[0] = 1;
      fib[1] = 1;
      for(int i = 2; i <= n; i++) {
         fib[i] = fib[i-1] + fib[i-2];
      }

      return fib[n];
   }

}