'''
Description: 
Autor: Au3C2
Date: 2021-02-04 11:15:35
LastEditors: Au3C2
LastEditTime: 2021-02-04 11:16:14
'''
class Solution:
    def characterReplacement(self, s: str, k: int) -> int:
        n = len(s)
        if n == 0:
            return 0
        if k >= n :
            return k
               
        count = collections.Counter()
        lp = 0 #左指针
        # lookup = []
        max_len = k + 1
        cur_len = 0
        for rp in range(n): #右指针
            cur_len += 1
            count[s[rp]] += 1
            # lookup = s[lp:rp+1]
            max_n = max(list(count.values()))
            # if max_n == n:
            #     return n
            # if cur_len > isSatisfied(max_n,k,cur_len,max_len):
            if cur_len > max_len and max_n + k >= cur_len:
                max_len = cur_len
                
            if max_n + k < cur_len:
                count[s[lp]] -= 1
                lp += 1
                cur_len -= 1

        return max_len
    
# 滑动窗口，中等，每日一题。之前做过的
# https://leetcode-cn.com/problems/longest-repeating-character-replacement/