<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>

typedef long long ll;
const int MOD1 = 1e9 + 7;
const int MOD2 = 1e9 + 9;
const int st1 = 137;
const int st2 = 2137;
class Solution {
public:
    pair<int, int> hash(string &s, int a, int b){
        int hash1=0, hash2=0;
        for(int i=a;i<=b;i++){
            hash1=((ll)hash1*st1+s[i])%MOD1;
            hash2=((ll)hash2*st2+s[i])%MOD2;
        }
        return {hash1, hash2};
    }
    vector<string> findAllConcatenatedWordsInADict(vector<string>& words) {
        vector<string> ans;
        set<pair<int, int>> dic;
        for(auto &v : words){
            dic.insert(hash(v, 0, (int)v.size()-1));
        }
        for(auto &v : words){
            pair<int, int> pm=hash(v, 0, (int)v.size()-1);
            dic.erase(pm);
            int n=(int)v.size();
            vector<bool> dp(n, 0);
            vector<vector<pair<int, int>>> calc(n, vector<pair<int, int>>(n, {0, 0}));
            for(int i=0;i<n;i++){
                for(int j=i;j<n;j++){
                    calc[i][j]=hash(v, i, j);
                }
            }
            for(int i=0;i<n;i++){
                if(dic.find(calc[0][i])!=dic.end()){
                    dp[i]=true;
                    continue;
                }
                for(int j=0;j<i;j++){
                    if(dp[j]&&dic.find(calc[j+1][i])!=dic.end()){
                        dp[i]=true;
                        break;
                    }
                }
            }
            if(dp[n-1]) ans.push_back(v);
            dic.insert(pm);
        }
        return ans;
    }
};
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