Groovy example source code file (recursive.java)

This example Groovy source code file (recursive.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

ack, ack, fib, fib, tak, tak

The Groovy recursive.java source code

// ---------------------------------------------------------------------
// The Great Computer Language Shootout
// http://shootout.alioth.debian.org/
//
// Code based on / inspired by existing, relevant Shootout submissions
//
// Contributed by Anthony Borla
// ---------------------------------------------------------------------

public class recursive
{
  public static void main(String args[])
  {
    int n = Integer.parseInt(args[0]);

    System.out.printf("Ack(3,%d): %d\n", n, ack(3, n));
    System.out.printf("Fib(%.1f): %.1f\n", 27.0 + n, fib(27.0 + n));

    n -= 1;
    System.out.printf("Tak(%d,%d,%d): %d\n", n * 3, n * 2, n, tak(n * 3, n * 2, n));

    System.out.printf("Fib(3): %d\n", fib(3));
    System.out.printf("Tak(3.0,2.0,1.0): %.1f\n", tak(3.0, 2.0, 1.0));
  }

  public static int ack(int m, int n)
  {
    if (m == 0) return n + 1;
    if (n == 0) return ack(m - 1, 1);
    return ack(m - 1, ack(m, n - 1));
  }

  public static int fib(int n)
  {
    if (n < 2) return 1;
    return fib(n - 2) + fib(n - 1);
  }

  public static double fib(double n)
  {
    if (n < 2.0) return 1.0;
    return fib(n - 2.0) + fib(n - 1.0);
  }

  public static int tak(int x, int y, int z)
  {
    if (y >= x) return z;
    return tak(tak(x - 1, y, z), tak(y - 1, z, x), tak(z - 1, x, y));
  }

  public static double tak(double x, double y, double z)
  {
    if (y >= x) return z;
    return tak(tak(x - 1.0, y, z), tak(y - 1.0, z, x), tak(z - 1.0, x, y));
  }
}