1156. Swap For Longest Repeated Character Substring

class Solution {
    public int maxRepOpt1(String text) {
        Map<Character, Integer> countMap = new HashMap<>();
        for (int i = 0; i < text.length(); i++) {
            countMap.put(text.charAt(i), countMap.getOrDefault(text.charAt(i), 0) + 1);
        }

        int maxLength = 1;

        for (int i = 0; i < text.length(); ) {
            char c = text.charAt(i);

            int j = i;
            while (j < text.length() && text.charAt(j) == c) {
                j++;
            }
            // now: j == text.length() or text.charAt(j) != c
            int leftLength = j - i;

            int k = j + 1; // 尝试跳过不同的字符继续进行匹配
            while (k < text.length() && text.charAt(k) == c) {
                k++;
            }
            int rightLength = k - (j + 1);

            maxLength = Math.max(maxLength, Math.min(leftLength + 1 + rightLength, countMap.get(c)));
            i = j;
        }

        return maxLength;
    }
}

References

1156. Swap For Longest Repeated Character Substring