Fri. Apr 12th, 2024

Given an array of string words. Return all strings in words which is substring of another word in any order. 

String words[i] is substring of words[j], if can be obtained removing some characters to left and/or right side of words[j].

Example 1:

Input: words = ["mass","as","hero","superhero"]
Output: ["as","hero"]
Explanation: "as" is substring of "mass" and "hero" is substring of "superhero".
["hero","as"] is also a valid answer.

Example 2:

Input: words = ["leetcode","et","code"]
Output: ["et","code"]
Explanation: "et", "code" are substring of "leetcode".

Example 3:

Input: words = ["blue","green","bu"]
Output: []
class Solution {
    public List<String> stringMatching(String[] words) {
        Arrays.sort(words, new java.util.Comparator<String>() {
            public int compare(String s1, String s2) {
                return s1.length() - s2.length();
        List<String> subStringList = new ArrayList<String>();
        for(int i=0;i<words.length;i++){
            String s1 = words[i];
            for(int j=i+1;j<words.length;j++){
                String s2 = words[j];
        return subStringList;