Count Substrings With K-Frequency Characters I
Given a string s and an integer k, return the total number of substrings of s where at least one character appears at least k times.
Example 1
Input
s = "abacb", k = 2Output
4The valid substrings are "aba", "abac", "abacb", and "bacb".
Example 2
Input
s = "abcde", k = 1Output
15All substrings are valid because every character appears at least once.
Constraints
- 1 <= s.length <= 3000
- 1 <= k <= s.length
- s consists only of lowercase English letters.