Longest Repeating Character Replacement

You are given a string s and an integer k. You can choose any character in the string and change it to any other uppercase English letter. You may perform this operation at most k times.

Return the length of the longest substring that can be made to contain all the same character after at most k replacements.

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Example 1

Input: s = "ABAB", k = 2
Output: 4
Explanation: Replace both 'A's with 'B' (or both 'B's with 'A') to get "BBBB" or "AAAA", length 4.

Example 2

Input: s = "AABABBA", k = 1
Output: 4
Explanation: Replace the one 'B' in "AABA" to get "AAAA", which has length 4.

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Constraints

• 1 <= s.length <= 10^5
• s consists of only uppercase English letters.
• 0 <= k <= s.length