241007 Cubeditor

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	String inputString = br.readLine();

	String[] suffixes = new String[inputString.length()];
	for (int i = 0; i < inputString.length(); i++) {
		suffixes[i] = inputString.substring(i);
	}

	Arrays.sort(suffixes);

	int maxCommonLength = findMaxCommonPrefix(suffixes);
	System.out.println(maxCommonLength);
}

private static int findMaxCommonPrefix(String[] sortedSuffixes) {
	int maxLength = -1;

	for (int i = 1; i < sortedSuffixes.length; i++) {
		int commonLength = getCommonPrefixLength(sortedSuffixes[i - 1], sortedSuffixes[i]);
		if (commonLength > maxLength) {
			maxLength = commonLength;
		}
	}

	return maxLength;
}

private static int getCommonPrefixLength(String first, String second) {
	int commonCount = 0;
	int minLength = Math.min(first.length(), second.length());

	while (commonCount < minLength && first.charAt(commonCount) == second.charAt(commonCount)) {
		commonCount++;
	}

	return commonCount;
}

출처:https://www.acmicpc.net/problem/1701