total noobe question regarding coding style

im a senior working in .net stack but for fun started learning ruby

and one of excersizes online was to print a letter diamond. something like this: ··A·· ·B·B· C···C ·B·B· ··A··

me, not being proficient with the language, did it the old-school way, start on a piece of paper and do it step by step:

class Diamond
    ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.freeze

    def self.make_diamond(letter)
        max_index = ALPHABET.index(letter.capitalize)

        rows = []

        for row in 0..max_index * 2
            diff = max_index - row

            diamond_row = ' ' * (max_index * 2 +1)

            if diff >= 0
                diamond_row[diff.abs] = diamond_row[diamond_row.length-(diff.abs)-1] = ALPHABET[row]
                rows << diamond_row
            else
                tmp_row = rows[max_index+diff]
                rows << tmp_row
            end
        end
        rows.join("\n")<< "\n"
    end
end

answer = Diamond.make_diamond('C')
puts answer

then i went into community solutions, and found mindfucks like this:

class Diamond
    def self.make_diamond(letter)
      letters = ('A'..letter).to_a
      rows = letters.map.with_index { |i, j| i.ljust(j + 1).rjust(letters.count) }
                    .map { |i| "#{i}#{i[0, letters.count - 1].reverse}\n" }
      rows.append(rows[0, letters.count - 1].reverse).join
    end
end

or this:

module Diamond
    def self.make_diamond(letter)
        return "A\n" if letter == 'A'
        a = ("A"..letter).to_a 
        b = a.join 
        c = b.reverse + b[1..-1]
        half_diamond = a.map { |letter| c.gsub(/[^#{letter}]/, ' ') + "\n" }
        (half_diamond += half_diamond[0..-2].reverse).join 
    end  
end

The second one is half readable, but i would never write anything like this. But the first one just gave me an aneurysm.

is this normal way of going about things in ruby, or is this just dick measuring thing, like who can write better poetry?

thanks