OpenBSD-4.6/regress/usr.bin/bc/t18.in

/* $OpenBSD: t18.in,v 1.1 2003/12/09 12:49:01 otto Exp $ */
/*
 * Copyright (c) 2003 Amit Singh <amit_s@acm.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * The Towers Of Hanoi
 * bc version
 * http://hanoi.kernelthread.com
 */

define moveit(i, j) {
  print "move "
  print i
  print " --> "
  print j
  print "\n"
}

define dohanoi(n, h, d, o) {
  if (n > 0) {	
    silence = dohanoi(n-1, h, o, d)
    silence = moveit(h, d)
    silence = dohanoi(n-1, o, d, h)
  }
}

define hanoi(n) {
  silence = dohanoi(n, 1, 3, 2)
}

hanoi(5)