1
2(********************************************************************)
3(*                                                                  *)
4(*  hanoi.sd7     Solve the tower of hanoi problem                  *)
5(*  Copyright (C) 1991, 1992, 1993, 1994, 2004  Thomas Mertes       *)
6(*                                                                  *)
7(*  This program is free software; you can redistribute it and/or   *)
8(*  modify it under the terms of the GNU General Public License as  *)
9(*  published by the Free Software Foundation; either version 2 of  *)
10(*  the License, or (at your option) any later version.             *)
11(*                                                                  *)
12(*  This program is distributed in the hope that it will be useful, *)
13(*  but WITHOUT ANY WARRANTY; without even the implied warranty of  *)
14(*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   *)
15(*  GNU General Public License for more details.                    *)
16(*                                                                  *)
17(*  You should have received a copy of the GNU General Public       *)
18(*  License along with this program; if not, write to the           *)
19(*  Free Software Foundation, Inc., 51 Franklin Street,             *)
20(*  Fifth Floor, Boston, MA  02110-1301, USA.                       *)
21(*                                                                  *)
22(********************************************************************)
23
24
25$ include "seed7_05.s7i";
26  include "stdio.s7i";
27
28
29const proc: hanoi (in integer: disk, in string: source, in string: dest, in string: via) is func
30  begin
31    if disk > 0 then
32      hanoi(pred(disk), source, via, dest);
33      writeln("Move disk " <& disk <& " from " <& source <& " to " <& dest);
34      hanoi(pred(disk), via, dest, source);
35    end if;
36  end func;
37
38
39const proc: hanoi (in integer: height) is func
40  begin
41    writeln("To move a tower of height " <& height <& " from left to right:");
42    writeln;
43    hanoi(height, "left", "right", "middle");
44    writeln;
45  end func;
46
47
48const proc: main is func
49  begin
50    writeln;
51    writeln("Tower of Hanoi:");
52    writeln;
53    hanoi(4);
54  end func;
55