# LeetCode 1408. String Matching in an Array

## Description

https://leetcode.com/problems/string-matching-in-an-array/

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.

## Explanation

Check if word can be found as substring in any other words.

## Python Solution

``````class Solution:
def stringMatching(self, words: List[str]) -> List[str]:
results = []

words_set = set(words)

for i, word in enumerate(words):
for key in words_set:

if key != word and key.find(word) != -1:

results.append(word)
break

return results
``````
• Time Complexity: O(N^2).
• Space Complexity: O(N).