> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/1542-find-longest-awesome-substring.md).

# 1542. Find Longest Awesome Substring

<https://leetcode.com/problems/find-longest-awesome-substring>

## Description

Given a string `s`. An *awesome* substring is a non-empty substring of `s` such that we can make any number of swaps in order to make it palindrome.

Return the length of the maximum length **awesome substring** of `s`.

**Example 1:**

```
**Input:** s = "3242415"
**Output:** 5
**Explanation:** "24241" is the longest awesome substring, we can form the palindrome "24142" with some swaps.
```

**Example 2:**

```
**Input:** s = "12345678"
**Output:** 1
```

**Example 3:**

```
**Input:** s = "213123"
**Output:** 6
**Explanation:** "213123" is the longest awesome substring, we can form the palindrome "231132" with some swaps.
```

**Example 4:**

```
**Input:** s = "00"
**Output:** 2
```

**Constraints:**

* `1 <= s.length <= 10^5`
* `s` consists only of digits.

## ac

```java
```