424.md

424 Longest Repeating Character Replacement

Description

link

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Solution

传统滑动窗口可以解决问题，看代码

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Code

O(n)

class Solution:
    def characterReplacement(self, s: str, k: int) -> int:
        l, r = 0, 0
        res = 0
        if not s:
            return 0

        cnt = collections.Counter(s[l])
        while r < len(s) - 1:
            r += 1
            cnt[s[r]] += 1
            max_cnt_num = cnt.most_common(1)[0][1]
            while r - l + 1 - max_cnt_num > k:
                cnt[s[l]] -= 1
                l += 1
            res = max(res, r - l + 1)
        return res