This solution doesn't actually understand the logic of the encoder. I was surprised by fact that other solutions actually understood logic of encoder.
This one is just based on fact that one letter transforms to one letter & same letter from same location transforms one way, not relying on other letters.
And then it just dynamically creates collection of encoded letters in all possible positions.

Performance: O(N) where N is length of the number.

So you want to say that 2 is same denominator as 12? Seriously?