# GeetCode Hub

You are given a string `s`, a split is called good if you can split `s` into 2 non-empty strings `p` and `q` where its concatenation is equal to `s` and the number of distinct letters in `p` and `q` are the same.

Return the number of good splits you can make in `s`.

Example 1:

```Input: s = "aacaba"
Output: 2
Explanation: There are 5 ways to split `"aacaba"` and 2 of them are good.
("a", "acaba") Left string and right string contains 1 and 3 different letters respectively.
("aa", "caba") Left string and right string contains 1 and 3 different letters respectively.
("aac", "aba") Left string and right string contains 2 and 2 different letters respectively (good split).
("aaca", "ba") Left string and right string contains 2 and 2 different letters respectively (good split).
("aacab", "a") Left string and right string contains 3 and 1 different letters respectively.
```

Example 2:

```Input: s = "abcd"
Output: 1
Explanation: Split the string as follows ("ab", "cd").
```

Example 3:

```Input: s = "aaaaa"
Output: 4
Explanation: All possible splits are good.```

Example 4:

```Input: s = "acbadbaada"
Output: 2
```

Constraints:

• `s` contains only lowercase English letters.
• `1 <= s.length <= 10^5`

class Solution { public int numSplits(String s) { } }