Watch 10 video solutions for Count Vowel Strings in Ranges, a medium level problem involving Array, String, Prefix Sum. This walkthrough by NeetCodeIO has 7,973 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
You are given a 0-indexed array of strings words and a 2D array of integers queries.
Each query queries[i] = [li, ri] asks us to find the number of strings present in the range li to ri (both inclusive) of words that start and end with a vowel.
Return an array ans of size queries.length, where ans[i] is the answer to the ith query.
Note that the vowel letters are 'a', 'e', 'i', 'o', and 'u'.
Example 1:
Input: words = ["aba","bcb","ece","aa","e"], queries = [[0,2],[1,4],[1,1]] Output: [2,3,0] Explanation: The strings starting and ending with a vowel are "aba", "ece", "aa" and "e". The answer to the query [0,2] is 2 (strings "aba" and "ece"). to query [1,4] is 3 (strings "ece", "aa", "e"). to query [1,1] is 0. We return [2,3,0].
Example 2:
Input: words = ["a","e","i"], queries = [[0,2],[0,1],[2,2]] Output: [3,2,1] Explanation: Every string satisfies the conditions, so we return [3,2,1].
Constraints:
1 <= words.length <= 1051 <= words[i].length <= 40words[i] consists only of lowercase English letters.sum(words[i].length) <= 3 * 1051 <= queries.length <= 1050 <= li <= ri < words.length