[dmichulke]

There's not really a way of measuring it but I used some different proxies such as

1. https://projecteuler.net/

Math-heavy but interesting

2. Clojure koans (http://www.4clojure.com/)

Here you're good if your solutions are close to the best solution - which is often short and readable (= elegant?)

There are probably similar koans for other languages and I'd also strongly recommend a functional language (because it frees yourself from the shackles of imperative and OO thinking, but YMMV)