240510 비슷한 단어

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	int n = Integer.parseInt(br.readLine());
	String first = br.readLine();
	int result = 0;

	for (int i = 0; i < n - 1; i++) {
		String str = br.readLine();
		int cnt = countCommonCharacters(first, str);
		if (isValidComparison(first, str, cnt)) {
			result++;
		}
	}
	System.out.println(result);
}

private static int countCommonCharacters(String first, String str) {
	int[] word = new int[26];
	for (int j = 0; j < first.length(); j++) {
		word[first.charAt(j) - 'A']++;
	}
	int cnt = 0;
	for (int j = 0; j < str.length(); j++) {
		if (word[str.charAt(j) - 'A'] > 0) {
			cnt++;
			word[str.charAt(j) - 'A']--;
		}
	}
	return cnt;
}

private static boolean isValidComparison(String first, String str, int cnt) {
	if (first.length() == str.length() && (first.length() == cnt || first.length() - 1 == cnt)) {
		return true;
	} else if (first.length() == str.length() - 1 && str.length() - 1 == cnt) {
		return true;
	} else return first.length() == str.length() + 1 && str.length() == cnt;
}

출처:https://www.acmicpc.net/problem/2607