# 1456. Maximum Number of Vowels in a Substring of Given Length

1456. Maximum Number of Vowels in a Substring of Given Length

```
class Solution:
def maxVowels(self, s: str, k: int) -> int:
vowels = {"a", "e", "i", "o", "u"}
count = 0
for i in range(k):
if s[i] in vowels:
count += 1
maxLength = count
for i in range(k, len(s)):
if s[i] in vowels:
count += 1
if s[i - k] in vowels:
count -= 1
maxLength = max(maxLength, count)
return maxLength
```