Lecture Notes on 04 Mar 2013

public class Fib
{
  public static int fib_iter (int n)
  {
    if ((n == 0) || (n == 1))
    {
      return n;
    }

    int f0 = 0;
    int f1 = 1;
    int f2 = f0 + f1;
    for (int i = 2; i < n; i++)
    {
      f0 = f1;
      f1 = f2;
      f2 = f0 + f1;
    }
    return f2;
  }

  public static int fib (int n)
  {
    if ((n == 0) || (n == 1))
    {
      return n;
    }
    else
    {
      return fib (n - 1) + fib (n - 2);
    }
  }

  public static void main (String[] args)
  {
    for (int i = 0; i < 10; i++)
    {
      System.out.println (fib(i) + "  " + fib_iter (i));
    }
  }
}



public class Towers
{
  public static void towers (int n, char source, char spare, char dest)
  {
    if (n == 1)
    {
      System.out.println ("Move disk from " + source + " to " + dest);
    }
    else
    {
      towers (n - 1, source, dest, spare);
      System.out.println ("Move disk from " + source + " to " + dest);
      towers (n - 1, spare, source, dest);
    }
  }

  public static void main (String[] args)
  {
    towers (4, 'A', 'B', 'C');
  }
}