I found this to be the smartest solution!

This has been a one of the most useful katas for me. I thought I new all the calling conventions but this kata proved it to be otherwise.

Exactly my thought. It took me so much time to solve it with an algorithm. And regex just in 2 lines.
Amazing.

Hadn't solved this kata yet, but already want to give my sincere gratitude to the author, @FrankK - that piece of puzzle wound my mind up quite a bit, thank you)
And to whomever is considering trying out this kata I can tell you that it'd be an excellent choice

I will take this solution into account. I think it's time for me to finally master regex.

Didn't know that there is a string::sort method while solving this kata. Not cool.