1297. Maximum Number of Occurrences of a Substring

https://leetcode.com/problems/maximum-number-of-occurrences-of-a-substring

Description

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.

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