1408. String Matching in an Array

Problem

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: []

  Constraints:

• 1 <= words.length <= 100

• 1 <= words[i].length <= 30

• words[i] contains only lowercase English letters.

• It's guaranteed that words[i] will be unique.

Solution (Java)

class Solution {
    public List<String> stringMatching(String[] words) {
        Set<String> set = new HashSet<>();
        for (String word : words) {
            for (String s : words) {
                if (!word.equals(s) && word.length() < s.length() && s.contains(word)) {
                    set.add(word);
                }
            }
        }
        return new ArrayList<>(set);
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).