The goal was not to rewrite the code, just make it work. But of course, this one is much clearer than the previous one.

This made my day aha

The main method play() is very readable, well done !

The description should specify that we have to find distance btw a letter and its nearest vowel, IN THE GIVEN STING. And not in the ALPHABET. Lost so much time trying to understand these examples.

Your problem comes from the concept of proximity. The description says that we sould return the pair with the lowest last element's index. It means that in [10, 5, 2, 3, 7, 5] the answer is [3,7]. In [10, 5, 2, 3, 5, 7] the answer is [5,5] because the last 5 has an index lower than 7.

I do not agree with you. In english, space char is the word's separator. An anagram is a WORD that can be mixed to create another. So, in 'E h llo' there are 3 differents words.
If you consider 'E h llo' as string, and not as a word, spaces are part of this string.

To me, if this issue is not specified in the instructions, your exemple should return false by default.

Just an opinion