<p>You are given an array of strings <code>products</code> and a string <code>searchWord</code>.</p>

<p>Design a system that suggests at most three product names from <code>products</code> after each character of <code>searchWord</code> is typed. Suggested products should have common prefix with <code>searchWord</code>. If there are more than three products with a common prefix return the three lexicographically minimums products.</p>

<p>Return <em>a list of lists of the suggested products after each character of </em><code>searchWord</code><em> is typed</em>.</p>

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

<pre>
<strong>Input:</strong> products = [&quot;mobile&quot;,&quot;mouse&quot;,&quot;moneypot&quot;,&quot;monitor&quot;,&quot;mousepad&quot;], searchWord = &quot;mouse&quot;
<strong>Output:</strong> [[&quot;mobile&quot;,&quot;moneypot&quot;,&quot;monitor&quot;],[&quot;mobile&quot;,&quot;moneypot&quot;,&quot;monitor&quot;],[&quot;mouse&quot;,&quot;mousepad&quot;],[&quot;mouse&quot;,&quot;mousepad&quot;],[&quot;mouse&quot;,&quot;mousepad&quot;]]
<strong>Explanation:</strong> products sorted lexicographically = [&quot;mobile&quot;,&quot;moneypot&quot;,&quot;monitor&quot;,&quot;mouse&quot;,&quot;mousepad&quot;].
After typing m and mo all products match and we show user [&quot;mobile&quot;,&quot;moneypot&quot;,&quot;monitor&quot;].
After typing mou, mous and mouse the system suggests [&quot;mouse&quot;,&quot;mousepad&quot;].
</pre>

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

<pre>
<strong>Input:</strong> products = [&quot;havana&quot;], searchWord = &quot;havana&quot;
<strong>Output:</strong> [[&quot;havana&quot;],[&quot;havana&quot;],[&quot;havana&quot;],[&quot;havana&quot;],[&quot;havana&quot;],[&quot;havana&quot;]]
<strong>Explanation:</strong> The only word &quot;havana&quot; will be always suggested while typing the search word.
</pre>

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

<ul>
	<li><code>1 &lt;= products.length &lt;= 1000</code></li>
	<li><code>1 &lt;= products[i].length &lt;= 3000</code></li>
	<li><code>1 &lt;= sum(products[i].length) &lt;= 2 * 10<sup>4</sup></code></li>
	<li>All the strings of <code>products</code> are <strong>unique</strong>.</li>
	<li><code>products[i]</code> consists of lowercase English letters.</li>
	<li><code>1 &lt;= searchWord.length &lt;= 1000</code></li>
	<li><code>searchWord</code> consists of lowercase English letters.</li>
</ul>

class Trie{
public:
    std::map<char, Trie*> children;
    bool is_end = false;
};

class Solution {
private:
    const int max_nof_strs = 3;
    void get_trie_strs(Trie* node, string buf_str, vector<string>& dst_strs){
        if(dst_strs.size() >= max_nof_strs) return;

        if(node->is_end){
            dst_strs.push_back(buf_str);
        }

        for(auto itr = node->children.begin(); itr != node->children.end(); ++itr){
            char cur_char = itr->first;
            Trie* next = itr->second;
            get_trie_strs(next, buf_str + cur_char, dst_strs);
        }
    }

public:
    vector<vector<string>> suggestedProducts(vector<string>& products, string searchWord) {
        Trie* head = new Trie;
        head->is_end = false;
        for(string& cur_string : products){
            Trie* node = head;
            for(int i_char = 0; i_char < cur_string.length(); ++i_char){
                char cur_char = cur_string[i_char];
                if(node->children.find(cur_char) == node->children.end()){
                    node->children[cur_char] = new Trie();
                }
                node = node->children[cur_char];
            }
            node->is_end = true;
        }

        vector<vector<string>> result;
        string buf_str;
        Trie* node = head;
        for(int i_char = 0; i_char < searchWord.size(); ++i_char){
            char cur_char = searchWord[i_char];
            buf_str += cur_char;
            vector<string> cur_strs;
            if(node != nullptr && node->children.find(cur_char) == node->children.end()){
                node = nullptr;
            }
            if(node != nullptr){
                node = node->children[cur_char];
                this->get_trie_strs(node, buf_str, cur_strs);
            }
            result.push_back(cur_strs);
        }

        return result;
    }
};
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