1641. Count Sorted Vowel Strings

Given an integer n, return the number of strings of length n that consist only of vowels (a, e, i, o, u) and are lexicographically sorted. A string s is lexicographically sorted if for all valid i, s[i] is the same as or comes before s[i+1] in the alphabet. Example 1: Input: n = 1 Output: 5 Explanation: The 5 sorted strings that consist of vowels only are ["a","e","i","o","u"]. Example 2: I