gistfile1.rb

# Efficiently make a grid coordinate out of a flat integer size, with the limit set to 2 per row
# Change occurence of 2 in method to change limit per row
def grid_size(size)
  Array.new(size){|n| [n % 2, n / 2]}
end

# Example return
grid_size(6) => [[0, 0], [1, 0], [0, 1], [1, 1], [0, 2], [1, 2]]

# Or in more readable return format
[[0, 0], [1, 0],
 [0, 1], [1, 1],
 [0, 2], [1, 2]]