Generate letters to represent number using ruby?

Question

I would like to generate a sequence of letters i.e. \"A\", \"DE\" \"GJE\", etc. that correspond to a number. The first 26 are pretty easy so 3 returns \"C\", 26 returns \"Z\

Answer 1

Using the base conversion method found here. I also changed it for the lack of "0" that we have in this numbering system. End cases have been addressed.

def baseAZ(num)
  # temp variable for converting base
  temp = num

  # the base 26 (az) number
  az = ''

  while temp > 0

    # get the remainder and convert to a letter
    num26 = temp % 26
    temp /= 26

    # offset for lack of "0"
    temp -= 1 if num26 == 0

    az = (num26).to_s(26).tr('0-9a-p', 'ZA-Y') + az
  end

  return az
end

irb I/O:

>> baseAZ(1)
=> "A"
>> baseAZ(26^2 + 1)
=> "Y"
>> baseAZ(26*26 + 1)
=> "ZA"
>> baseAZ(26*26*26 + 1)
=> "YZA"
>> baseAZ(26*26*26 + 26*26 + 1)
=> "ZZA"