From: dblack@...
Date: 2006-11-15T03:53:39+09:00
Subject: Re: Convert singel dimention array into grid

Hi --

On Wed, 15 Nov 2006, Tim Pease wrote:

> On 11/14/06, Giant Cranes <ruby-forum@gavinjoyce.com> wrote:
>> Hi,
>> 
>> I have been learning ruby for the past week and am completely hooked.
>> Most of the code I am producing is elegant (ruby's credit), although I
>> am having trouble elegantly converting a single dimension array with 16
>> elements into a two-dimension grid [4x4].
>> 
>> Here is what I have so far:
>> 
>> @array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
>> @grid = Array.new
>> 
>> i = 0
>> index = 0
>> 0.upto(3) do |i|
>>   j = 0
>>   0.upto(3) do |j|
>>     @grid[i] = Array.new if j == 0
>>     @grid[i][j] = @array[index]
>>     index += 1
>>     j += 1
>>   end
>>   i += 1
>> end
>> 
>> @grid
>> 
>
> Let the golfing commence!
>
> require 'enumerator'
>
> @array = (1..16).to_a
> @grid = Array.new(4) {|idx| Array.new(4)}
>
> @array.each_with_index do |val, idx|
> @grid[idx/4][idx%4] = val
> end

Well, if we're golfing:

require'enumerator'
g=*(1..16).enum_slice(4)


David

-- 
                   David A. Black | dblack@rubypal.com
Author of "Ruby for Rails"   [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog)        [2] | Co-director, Ruby Central, Inc.   [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com    | [4] http://www.rubycentral.org