Find the length of the longest substring T of a given string (consists of lowercase letters only) such that every character in T appears no less than k times.
Example 1:
Input:
s = "aaabb", k = 3
Output:
3
The longest substring is "aaa", as 'a' is repeated 3 times.
Example 2:
Input:
s = "ababbc", k = 2
Output:
5
The longest substring is "ababb", as 'a' is repeated 2 times and 'b' is repeated 3 times.
My code:
import numpy as np
class Solution(object):
def longestSubstring(self, s, k):
if len(s) < k:
return 0
c = min(set(s), key=s.count)
if s.count(c) >= k:
return len(s)
return max(self.longestSubstring(t, k) for t in s.split(c))
Solution: https://leetcode.com/problems/longest-substring-with-at-least-k-repeating-characters/