Out of curiousity I benchmarked the two, this one is indeed 5 times faster.

Look at my faster solution without explicit sort. )))

The while at the beginning was a good one, it help me to optimize my solution.

Hi check out my solution, its not bruteforce like the other solution here

I have something similar, but I tried to minimize unnecessary calculations and endowed the variables with more descriptive (and longer xD) names
https://www.codewars.com/kata/reviews/55984e63be3bb762bc000138/groups/61da2a248dab43000192593e

True!

I thought the same, but i written an more extensive code , because i'm dosnt understood indexOf method. Now i understand it and i have more power xd

its a clever solution
as i understand you find the previous element and compare them
clever clever

This looks very inefficient.

I love this solution

What's going on here? What do you call this algorithm?

actually good and simple

The two number must be adjacent...ok...
I should read it more carefully.

GOT EM

"You don't need to validate the form of the Roman numeral."

"XXC" is NOT a valid roman numeral.

;))