3445. Maximum Difference Between Even and Odd Frequency II

Description

You are given a string s and an integer k. Your task is to find the maximum difference between the frequency of two characters, freq[a] - freq[b], in a substring subs of s, such that:

• subs has a size of at least k.
• Character a has an odd frequency in subs.
• Character b has an even frequency in subs.

Return the maximum difference.

Note that subs can contain more than 2 distinct characters.

 

Example 1:

Input: s = "12233", k = 4

Output: -1

Explanation:

For the substring "12233", the frequency of '1' is 1 and the frequency of '3' is 2. The difference is 1 - 2 = -1.

Example 2:

Input: s = "1122211", k = 3

Output: 1

Explanation:

For the substring "11222", the frequency of '2' is 3 and the frequency of '1' is 2. The difference is 3 - 2 = 1.

Example 3:

Input: s = "110", k = 3

Output: -1

 

Constraints:

• 3 <= s.length <= 3 * 104
• s consists only of digits '0' to '4'.
• The input is generated that at least one substring has a character with an even frequency and a character with an odd frequency.
• 1 <= k <= s.length

Solutions

Solution 1

Python3JavaC++Go

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