Nice String in Kotlin

Nice String

We'll say a string is nice if at least two of the following conditions are satisfied:

1. It doesn't contain substrings bu, ba or be;
2. It contains at least three vowels (vowels are a, e, i, o and u);
3. It contains a double letter (at least two similar letters following one another), like b in "abba".

Your task is to check whether a given string is nice. Strings for this task will consist of lowercase letters only. Note that for the purpose of this task, we don't consider 'y' as a vowel.

• Example 1

  "bac" isn't nice. No conditions are satisfied: it contains a ba substring, contains only one vowel and no doubles.

• Example 2

  "aza" isn't nice. Only the first condition is satisfied, but the string doesn't contain enough vowels or doubles.

• Example 3

  "abaca" isn't nice. The second condition is satisfied: it contains three vowels a, but the other two aren't satisfied: it contains ba and no doubles.

• Example 4

  "baaa" is nice. The conditions #2 and #3 are satisfied: it contains three vowels a and a double a.

• Example 5

  "aaab" is nice, because all three conditions are satisfied.