# 2559. Count Vowel Strings in Ranges
###### tags: `Leetcode` `Medium` `Line Sweep`
Link: https://leetcode.com/problems/count-vowel-strings-in-ranges/description/
## Code

class Solution:
    def vowelStrings(self, words: List[str], queries: List[List[int]]) -> List[int]:
        vowels = {'a', 'e', 'i', 'o', 'u'}
        def checkString(word: str) -> bool:
            return word[0] in vowels and word[-1] in vowels
        count = [0]
        for word in words:
            if checkString(word): count.append(count[-1]+1)
            else: count.append(count[-1])
        ans = []
        for start, end in queries:
            ans.append(count[end+1]-count[start])
        return ans