<p>Given an array of strings <code>words</code> (<strong>without duplicates</strong>), return <em>all the <strong>concatenated words</strong> in the given list of</em> <code>words</code>.</p>

<p>A <strong>concatenated word</strong> is defined as a string that is comprised entirely of at least two shorter words (not necessarily distinct)&nbsp;in the given array.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;cat&quot;,&quot;cats&quot;,&quot;catsdogcats&quot;,&quot;dog&quot;,&quot;dogcatsdog&quot;,&quot;hippopotamuses&quot;,&quot;rat&quot;,&quot;ratcatdogcat&quot;]
<strong>Output:</strong> [&quot;catsdogcats&quot;,&quot;dogcatsdog&quot;,&quot;ratcatdogcat&quot;]
<strong>Explanation:</strong> &quot;catsdogcats&quot; can be concatenated by &quot;cats&quot;, &quot;dog&quot; and &quot;cats&quot;; 
&quot;dogcatsdog&quot; can be concatenated by &quot;dog&quot;, &quot;cats&quot; and &quot;dog&quot;; 
&quot;ratcatdogcat&quot; can be concatenated by &quot;rat&quot;, &quot;cat&quot;, &quot;dog&quot; and &quot;cat&quot;.</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> words = [&quot;cat&quot;,&quot;dog&quot;,&quot;catdog&quot;]
<strong>Output:</strong> [&quot;catdog&quot;]
</pre>

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

<ul>
	<li><code>1 &lt;= words.length &lt;= 10<sup>4</sup></code></li>
	<li><code>1 &lt;= words[i].length &lt;= 30</code></li>
	<li><code>words[i]</code> consists of only lowercase English letters.</li>
	<li>All the strings of <code>words</code> are <strong>unique</strong>.</li>
	<li><code>1 &lt;= sum(words[i].length) &lt;= 10<sup>5</sup></code></li>
</ul>

class Solution {
public:
    bool tell(string& curwrd,set<string>& st,int indx,string tillnow,map<pair<string,int>,bool>& mp)
    {
        int n=curwrd.size();
        if(indx==n)
        {
            if(st.find(tillnow)!=st.end()||tillnow=="")
                return true;
            return false;
        }
        if(mp.find({tillnow,indx})!=mp.end())
            return mp[{tillnow,indx}]; 
        string inswrd=tillnow+curwrd[indx];
        bool ans=false;
        if(st.find(inswrd)!=st.end())
            ans|=tell(curwrd,st,indx+1,"",mp);
        ans|=tell(curwrd,st,indx+1,inswrd,mp);
        return mp[{tillnow,indx}]=ans;
    }
    vector<string> findAllConcatenatedWordsInADict(vector<string>& words) {
     set<string> st;
     for(string str:words)
        st.insert(str);
     vector<string> ans;
     for(string str:words)
     {
        st.erase(str);
        map<pair<string,int>,bool> mp;
        if(tell(str,st,0,"",mp))
            ans.push_back(str);
        st.insert(str);
     }
     return ans;   
    }
};
220236