m1297.py

"""Maximum Number of Occurrences of a Substring
Given a string s, return the maximum number of ocurrences of any substring
under the following rules:

* The number of unique characters in the substring must be less than or equal to
  maxLetters.
* The substring size must be between minSize and maxSize inclusive.

Example 1:

* Input: s = "aababcaab", maxLetters = 2, minSize = 3, maxSize = 4
* Output: 2
* Explanation: Substring "aab" has 2 ocurrences in the original string.
  It satisfies the conditions, 2 unique letters and size 3 (between minSize and
  maxSize).

Example 2:

* Input: s = "aaaa", maxLetters = 1, minSize = 3, maxSize = 3
* Output: 2
* Explanation: Substring "aaa" occur 2 times in the string. It can overlap.

Example 3:

* Input: s = "aabcabcab", maxLetters = 2, minSize = 2, maxSize = 3
* Output: 3

Example 4:

* Input: s = "abcde", maxLetters = 2, minSize = 3, maxSize = 3
* Output: 0

Constraints:

* 1 <= s.length <= 10^5
* 1 <= maxLetters <= 26
* 1 <= minSize <= maxSize <= min(26, s.length)
* s only contains lowercase English letters.
"""