Count Vowels Permutations | Dataford Interview Questions

Count Vowels Permutation (LeetCode 1220): count strings of length n over vowels obeying follow rules

Asked in the OA stage. Given n, count strings of length n formed from a, e, i, o, and u, where a may be followed by e, e by a or i, i by a, e, o, or u, o by i or u, and u by a. Return the count modulo 1_000_000_007.

Input: One integer n. Output: An integer count.

Constraints

1 <= n <= 1000
The alphabet is exactly {a, e, i, o, u}
Return the answer modulo 1_000_000_007

Function Signature

def count_vowel_permutations(n):

Your question is Count Vowels Permutations. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Count Vowels Permutation (LeetCode 1220): count strings of length n over vowels obeying follow rules

Input: One integer n. Output: An integer count.

Constraints

1 <= n <= 1000
The alphabet is exactly {a, e, i, o, u}
Return the answer modulo 1_000_000_007

Function Signature

def count_vowel_permutations(n):

Your question is Count Vowels Permutations. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.