Across the alphabet
In this challenge, you have trouble remembering the letters of the alphabet. To circumvent this, you go up and down the alphabet, till you get to the letter.
Because you want your code to be portable, you'll be writing it with letter blocks. You have a limited amount of letter blocks because most of them got stolen so you need to make sure your code is as short as possible.
Input / Output pairs are separated by a blank line:
Ac ABc Ad ABcd fA fedCBA adB abcdcB Hello, World! HGfefghijkllmno, WVUTSrqpopqrqponmlkjihgfed!
Your goal is to chain adjacent letters with all the intermediate letters of the alphabet (
A-Za-z) between them. If capitalization differs, the capitalization should be transformed in the middle. If capitalization cannot be evenly transformed in the middle, it broken up after the middle. If a character isn't an alphabetical character, no transformation should be done.
This is code-golf so shortest code in bytes wins!
-10% Bonus: if your code chains digits