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

https://leetcode.com/problems/maximum-number-of-vowels-in-a-substring-of-given-length

## Description

Given a string `s` and an integer `k`.

Return _the maximum number of vowel letters_ in any substring of `s` with length `k`.

**Vowel letters** in English are (a, e, i, o, u).

**Example 1:**

```

**Input:** s = "abciiidef", k = 3
**Output:** 3
**Explanation:** The substring "iii" contains 3 vowel letters.
```

**Example 2:**

```

**Input:** s = "aeiou", k = 2
**Output:** 2
**Explanation:** Any substring of length 2 contains 2 vowels.
```

**Example 3:**

```

**Input:** s = "leetcode", k = 3
**Output:** 2
**Explanation:** "lee", "eet" and "ode" contain 2 vowels.
```

**Example 4:**

```

**Input:** s = "rhythms", k = 4
**Output:** 0
**Explanation:** We can see that s doesn't have any vowel letters.
```

**Example 5:**

```

**Input:** s = "tryhard", k = 4
**Output:** 1
```

**Constraints:**

* `1 <= s.length <= 10^5`
* `s` consists of lowercase English letters.
* `1 <= k <= s.length`

## ac

```java
```
