1624. Largest Substring Between Two Equal Characters

https://leetcode.com/problems/largest-substring-between-two-equal-characters

Description

Given a string s, return the length of the longest substring between two equal characters, excluding the two characters. If there is no such substring return -1.

A substring is a contiguous sequence of characters within a string.

Example 1:

**Input:** s = "aa"
**Output:** 0
**Explanation:** The optimal substring here is an empty substring between the two 'a's.

Example 2:

**Input:** s = "abca"
**Output:** 2
**Explanation:** The optimal substring here is "bc".

Example 3:

**Input:** s = "cbzxy"
**Output:** -1
**Explanation:** There are no characters that appear twice in s.

Example 4:

**Input:** s = "cabbac"
**Output:** 4
**Explanation:** The optimal substring here is "abba". Other non-optimal substrings include "bb" and "".

Constraints:

• 1 <= s.length <= 300

• s contains only lowercase English letters.

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