N个字符串中最长公用子串的Java实现

public class LongestCommonSubstring {
    public static String findLongestCommonSubstring(String[] strings) {
        if (strings == null || strings.length == 0) {
            return "";
        }
        
        String firstString = strings[0];
        int n = firstString.length();
        int m = strings.length;
        String longestSubstring = "";
        
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j <= n; j++) {
                String substring = firstString.substring(i, j);
                int k;
                for (k = 1; k < m; k++) {
                    if (!strings[k].contains(substring)) {
                        break;
                    }
                }
                if (k == m && substring.length() > longestSubstring.length()) {
                    longestSubstring = substring;
                }
            }
        }
        
        return longestSubstring;
    }

    public static void main(String[] args) {
        String[] strings = {"abcdef", "zabcf", "xabcdef"};
        System.out.println("Longest Common Substring: " + findLongestCommonSubstring(strings));
    }
}