<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 {
    map<pair<string,int>,bool> dp;
public:
    vector<string> findAllConcatenatedWordsInADict(vector<string>& words) {
        vector<string> ans;
        unordered_set<string> s(words.begin(),words.end());

        for(auto &w : words){
            string temp = w;
            s.erase(w);
            if(help(s,w,0))
                ans.push_back(w);
            s.insert(temp);
        }    

        return ans;
    }

    bool help(unordered_set<string> &s,string &w,int idx){
        if(idx == w.size()) return true;

        if(dp.find({w,idx}) != dp.end()) return dp[{w,idx}];
        for(int i=idx;i<w.size();i++){
            string curr = w.substr(idx,i-idx+1);
            if(s.find(curr) != s.end()){
                if(help(s,w,i+1))
                    return dp[{w,idx}] = true;
            }
        }

        return dp[{w,idx}] = false;
    }

    // bool wordBreak(string s, vector<string>& wordDict) {
    //     int n = s.size();
    //     vector<bool> dp(n+1,false);
    //     dp[n] = true;
        
    //     for(int i=n-1;i>=0;i--){
    //         for(auto w: wordDict){
    //             if(w == s) continue;
    //             if((i+w.size()-1 < s.size()) && s.substr(i,w.size()) == w){
    //                 dp[i] = dp[i+w.size()];
    //             }
    //             if(dp[i] == true)
    //                 break;
    //         }
    //     }
    //     return dp[0];
    // }
};
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