Leetcode-双指针/滑动窗口-424. 替换后的最长重复字符

题目：

题解：

代码：

class Solution {
    public int characterReplacement(String s, int k) {
        int left=0,right =0;
        int[] nums = new int[26];
        int len = s.length();
        int maxn = 0;
        while(right < len)
        {
           nums[s.charAt(right) - 'A']++;
           maxn = Math.max(maxn,nums[s.charAt(right) - 'A']);
           if( right-left +1 > maxn + k)
           {
               nums[s.charAt(left) - 'A']--;
               left++;
           }
          right++;
        }
        return right-left;

    }
}