<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 Trie{
public:
    Trie* children[26];
    bool whether_end;
    Trie():whether_end(false){
        fill(begin(children), end(children), nullptr);
    }
};
class Solution {
private:
    Trie * t;
    vector<string>res;
    void add_word(string & word){
        Trie * cur=t;
        for(char c:word){
            if(cur->children[c-'a']==nullptr){
                cur->children[c-'a']=new Trie();
            }
            cur=cur->children[c-'a'];
        }
        cur->whether_end=true;
    }
    void search_word2(Trie * old_trie, Trie * new_trie, string old_s, string new_s){
        if(old_trie==nullptr||new_trie==nullptr){
            return ;
        }
        if(old_trie->whether_end&&new_trie->whether_end){
            // cout<<old_trie->s<<" "<<new_trie->s<<endl;
            res.push_back(old_s);
            old_trie->whether_end=false;
        }
        if(new_trie->whether_end){
            search_word2(old_trie, t, old_s, new_s);
        }
        for(int i=0; i<26; i++){
            this->search_word2(old_trie->children[i], new_trie->children[i], 
            old_s+(char)(i+'a'), new_s+(char)(i+'a'));
        }
    }
    void search_word(Trie * current, string s){
        if(current==nullptr){
            return ;
        }
        if(current->whether_end){
            search_word2(current, t, s, "");
        }
        for(int i=0; i<26; i++){
            search_word(current->children[i], s+(char)(i+'a'));
        }
    }
public:
    vector<string> findAllConcatenatedWordsInADict(vector<string>& words) {
        this->t=new Trie();
        for(string &word:words){
            add_word(word);
        }
        search_word(t, "");
        return res;
    }
};
279943