Thanks to the person who helped me a lot, but I didn't understand why we do this. Can you help me explain it?

This fails some random tests, I had the same idea.

You should have subtracted 96, not 97.

Clever, but slow.

It's shocking how slow this solution is.

This is too slow.

The problem is with the apostrophes. There are no test cases with apostrophes at the beginning or end of a word, thus this passes.

I was about to post this purplemath link. Mathematically challenged, I found it more helpful than the link in the instructions.

Nice kata, but difficult.

Nice one.

Very easy kata.

I've tested the two approaches with 10000 numbers and the 2 loop approach was 65 ms, this one was 8 ms, so 8x faster. I've done it with an object, which is just as fast as a map in this case.

This is neither clever nor best practices in my humble opinion.

I can't believe that I'm the first one to apply your solution from the simpler problem here. I don't really understand the logic behind the steps, but I'll do my best to understand it and come up with my own solution. I keep seeing Pascal's triangle in the comments, that is a starting point. :-)