Condition to count could be made better for performance. Performance is going to be better simply by comparing every char in input string against a set of vowels.

Simple and also readable compared to other solutions.

Why is this 7kyu? Should be 8kyu.

Nice explanation for identity.

Scala testcases have contradicting testcases due to which submissions are failing.

Test Failed
Expected "[]", but got "[(B : 0) - (R : 0) - (D : 0) - (X : 0)]"

Test Failed
Expected "[(A : 0) - (W : 0) - (D : 0) - (C : 0) - (X : 0)]", but got "[]"

This should be fixed.

This should be a 7kyu IMO.

From learning point of view, I learnt about comparison op with string but from readability point of view, the solution left me ambigous about why explicit conversion to Integer is not implememted.

Was not aware filter can be applied on String in Scala because getClass() only returns java.lang.String. There is filter() method in java.lang.String class. What is the class to look for the documentaion scala string (if there is something like that)?
val s = "hello"
println(s.getClass())

Scala version of the problem is ambiguous. Where is the function to fix the bug? Even after completing partial implementation to solve given tests, test case was still failing. Question should be refactored or elaborated or clarified.

Another learning. List.tabulate was a new method I learnt today. Thanks for this solution

Any particular reason why traversal on Long is used instead of Int which requires only accumulator to be Long type? Is it to force sum to operate on Long?