You are given a string s and an integer k. You can choose any character of the string and change it to any other uppercase English character. You can perform this operation at most k times.
Return the length of the longest substring containing the same letter you can get after performing the above operations.
Input: s = "ABAB", k = 2
Output: 4
Explanation: Replace the two 'A's with two 'B's or vice versa.
Code :
class Solution {
public int characterReplacement(String s, int k) {
int len = s.length();
int[] count = new int[26];
int start = 0, maxCount = 0, maxLength = 0;
for (int end = 0; end < len; end++) {
maxCount = Math.max(maxCount, ++count[s.charAt(end) - 'A']);
while (end - start + 1 - maxCount > k) {
count[s.charAt(start) - 'A']--;
start++;
}
maxLength = Math.max(maxLength, end - start + 1);
}
return maxLength;
}
}