From: Dinakar <Desai.Dinakar@...>
Date: 2001-12-18T10:44:19+09:00
Subject: [ruby-talk:28827] what is wrong with this code

Hello:

I am new to Ruby. I am just playing around and trying to write code from C into
Ruby.
Following error message is code in Ruby and then in C. Can someone tell me what
is wrong with Rubycode. C code works fine where as Ruby code give error.
Error message as follows:
move ring 1 from peg a to peg c
move ring 1 from pega to peg b
./array_test.rb:5:in `towers': stack level too deep (SystemStackError)
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
         ... 2693 levels...
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:9:in `towers'
        from ./array_test.rb:18


================
Ruby  code
#!/usr/bin/env ruby

def towers( n, a, b, c)
  @n = n.to_i
  if (@n == 1)
  printf "move ring %d from peg %s to peg %s\n", @n, a, c
  return
  end
  towers((@n -1), a, c, b)
  printf "move ring %d from peg%s to peg %s\n", @n, a, c
  towers((@n -1), b, a, c)
  return
end
n = 5
a = 'a'
b = 'b'
c = 'c'
towers(n, a, b, c)


==============
C code:
#include <stdio.h>
void towers(int n, char a, char b, char c)
{
 if (n == 1)
 {
  printf("move ring %d from peg %c to peg %c\n", n, a, c);
  return ;
 }
 towers(n - 1, a, c, b);
 printf("Move ring %d from peg %c to peg %c\n", n, a, c);
 towers(n - 1, b, a, c);
 return;
}
main()
{
    int n = 5;
    char a= 'a';
    char b = 'c';
    char c = 'c';
 towers(n, a, b, c);
}
================

Thank you.

Dinakar
mnopq@mayo.edu