public class Solution
extends Object
1781 - Sum of Beauty of All Substrings\.
Medium
The **beauty** of a string is the difference in frequencies between the most frequent and least frequent characters.
* For example, the beauty of `"abaacc"` is `3 - 1 = 2`.
Given a string `s`, return _the sum of **beauty** of all of its substrings._
**Example 1:**
**Input:** s = "aabcb"
**Output:** 5
**Explanation:** The substrings with non-zero beauty are ["aab","aabc","aabcb","abcb","bcb"], each with beauty equal to 1.
**Example 2:**
**Input:** s = "aabcbaa"
**Output:** 17
**Constraints:**
* `1 <= s.length <= 500`
* `s` consists of only lowercase English letters.