problem:https://leetcode.com/problems/longest-repeating-character-replacement/
维护一个最多包含k个额外字符的滑动窗口。需要记录当前出现次数最多字符的出现次数来判断窗口是否合法，如果超过了，就把首指针向后挪一位，同时更新最多出现次数。对每个合法窗口，取其中的最大值。
class Solution { public: int characterReplacement(string s, int k) { int begin = 0; int res = 0; int maxLen = 0; vector<int> count(26, 0); for(int i = 0;i < s.size();i++) // end { count[s[i] - 'A']++; maxLen = max(maxLen, count[s[i] - 'A']); int len = i - begin + 1; if(len > maxLen + k) { count[s[begin] - 'A']--; begin++; maxLen = *max_element(count.begin(), count.end()); } // cout << res << " "; res = max(res, i - begin + 1); } return res; } };
转载于:https://www.cnblogs.com/fish1996/p/11337010.html
