From: Victor Reyes <victor.reyes@...>
Date: 2007-10-29T06:58:41+09:00
Subject: How do I define a dynamic Matrix or ....

------=_Part_5983_18733542.1193608720108
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Hello Team,

On my quest to learn Ruby, I implemented a known algorithm to solve an odd
nXn magic square.
I tested my code using a 3x3 and a 5x5 magic squares.
The problem that I am having is that I hard-code the initialization matrix.
In other words, if it is a 3x3 I define:

mm = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]

For a 5 x 5 I define :

mm = [[0,0,0, 0, 0], [0,0,0, 0, 0], [0,0,0, 0, 0],[0,0,0,0,0],[0,0,0,0,0]]

I want to be able to solve any size odd magic square. To do so, I need to be
able to define my matrix dynamically and on demand.
Can anyone tell me how to do that?

Attached is my current code. Please feel free to criticize it and make
recommendations. My disclaimer: I am a Ruby apprentice.

Thank you

Victor

#!/usr/local/bin/ruby -d -W0

def mag(size)
    r = 0                           # row
    c = 0                          # column
    index = 0                     # pointer

   # mm = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
    mm = [[0,0,0, 0, 0], [0,0,0, 0, 0], [0,0,0, 0,
0],[0,0,0,0,0],[0,0,0,0,0]]

    maxLoop = size * size                           # Magic Square size

    1.upto(maxLoop) do |n|

      case
          when n == 1
              c = (size / 2).floor                      # Will keep the
integer part, giving us the center in row 0
              mm[c][r] = n                             # This is: mm[c][0]
          when index >= size
              index = 0
              r = r + 1
              mm[c][r] = n
              puts " "
          else
              c = c + 1
              if c >= size
                c = 0
              end

              r = r -1
              if r < 0
                r = size - 1
              end
              mm[c][r] = n
          end
          index = index + 1

      puts "[#{c}][#{r}] = #{mm[c][r]} "

   end   # End upto

    ##############
    # Output the matrix    #
    ##############
    puts
    0.upto(size -1) do |r|
      0.upto(size -1) do |c|
        print "#{mm[c][r]} "
      end
      puts " "
    end

 end # End method mag

 # We start here

 p1 = ARGV[0].to_i

 mag( p1 )

------=_Part_5983_18733542.1193608720108--