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 = 1Output
5The 5 sorted strings that consist of vowels only are
["a", "e", "i", "o", "u"].Example 2
Input
n = 2Output
15The 15 sorted strings that consist of vowels only are
["aa", "ae", "ai", "ao", "au", "ee", "ei", "eo", "eu", "ii", "io", "iu", "oo", "ou", "uu"]; "ea" is not valid because e comes after a in the alphabet.Constraints
- 1 <= n <= 50