The goal was to add a certain character (r in our example) within words after vowels under certain rules (like add no r after double vowel, don't add if another r is in range of 3, ...). The fastest implementation would win ...
Example Input: Zwölf Boxkämpfer jagen Viktor quer über den großen Sylter Deich.
Example Output: Zwörlf Borxkärmpfer jargen Virktor quer über den großen Sylter Deich.