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.

解題

func beautySum(s string) int {
res := 0
​
for i := 0; i < len(s); i++ {
m := make(map[byte]int)
for j := i; j < len(s); j++ {
m[s[j]]++
​
min, max := math.MaxInt32, math.MinInt32
for _, v := range m {
if v < min {
min = v
}
if v > max {
max = v
}
}
res += max - min
}
}
return res
}