public class Solution
extends Object
943 - Find the Shortest Superstring\.
Hard
Given an array of strings `words`, return _the smallest string that contains each string in_ `words` _as a substring_. If there are multiple valid strings of the smallest length, return **any of them**.
You may assume that no string in `words` is a substring of another string in `words`.
**Example 1:**
**Input:** words = ["alex","loves","leetcode"]
**Output:** "alexlovesleetcode"
**Explanation:** All permutations of "alex","loves","leetcode" would also be accepted.
**Example 2:**
**Input:** words = ["catg","ctaagt","gcta","ttca","atgcatc"]
**Output:** "gctaagttcatgcatc"
**Constraints:**
* `1 <= words.length <= 12`
* `1 <= words[i].length <= 20`
* `words[i]` consists of lowercase English letters.
* All the strings of `words` are **unique**.