Largest Substring Between Two Equal Characters

1624. Largest Substring Between Two Equal Characters

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".

Constraints:
1 <= s.length <= 300
s contains only lowercase English letters.

/**
 * @param {string} s
 * @return {number}
 */
var maxLengthBetweenEqualCharacters = function(s) {
    const map = new Map();
    let max = -1;
    for(let i = 0; i < s.length; i++) {
        if (map.has(s[i])) {
            max = Math.max(max, i - map.get(s[i]) - 1)
        } else {
            map.set(s[i], i);
        }
    }
    return max;
};