initial commit

[brozturk]

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[duncanparkinson]

You can avoid the nested loops by using repeated_permutation, which will give you exactly the same combinations of n and x as nesting each.

[1, 4, 7].repeated_permutation(2).each do |n, x|
  subgrids << subgrid(n, x)
end

If you combine that with map you can also remove both the first and the last lines of the method.

[1, 4, 7].repeated_permutation(2).map do |n, x|
  subgrid(n, x)
end