<p>Given an array of string <code>words</code>. Return all strings in <code>words</code> which is substring of another word in <strong>any</strong> order.&nbsp;</p>

<p>String <code>words[i]</code> is substring of <code>words[j]</code>,&nbsp;if&nbsp;can be obtained removing some characters to left and/or right side of <code>words[j]</code>.</p>

<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;mass&quot;,&quot;as&quot;,&quot;hero&quot;,&quot;superhero&quot;]
<strong>Output:</strong> [&quot;as&quot;,&quot;hero&quot;]
<strong>Explanation:</strong> &quot;as&quot; is substring of &quot;mass&quot; and &quot;hero&quot; is substring of &quot;superhero&quot;.
[&quot;hero&quot;,&quot;as&quot;] is also a valid answer.
</pre>

<p><strong>Example 2:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;leetcode&quot;,&quot;et&quot;,&quot;code&quot;]
<strong>Output:</strong> [&quot;et&quot;,&quot;code&quot;]
<strong>Explanation:</strong> &quot;et&quot;, &quot;code&quot; are substring of &quot;leetcode&quot;.
</pre>

<p><strong>Example 3:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;blue&quot;,&quot;green&quot;,&quot;bu&quot;]
<strong>Output:</strong> []
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= words.length &lt;= 100</code></li>
	<li><code>1 &lt;= words[i].length &lt;= 30</code></li>
	<li><code>words[i]</code> contains only lowercase English letters.</li>
	<li>It&#39;s <strong>guaranteed</strong>&nbsp;that <code>words[i]</code>&nbsp;will be unique.</li>
</ul>