<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 TrieNode {
public:
    explicit TrieNode(char v) : value(v) {

    }
    char value;
    map<char, TrieNode*> children;
};

class Trie {
public:
    TrieNode* root;
    Trie() {
        root = new TrieNode(1);
    }

    void build(const string& word) {
        TrieNode* curr = root;
        for (auto c : word) {
            auto it = curr->children.find(c);
            if (it == curr->children.end()) {
                TrieNode* newNode = new TrieNode(c);
                curr->children[c] = newNode;
                curr = newNode;
            }
            else {
                curr = it->second;
            }
        }
        curr->children[0] = new TrieNode(0);
    }

    vector<string> search(const string& word) {
        string prefix = "";
        TrieNode* curr = root;
        for (auto c : word) {
            auto it = curr->children.find(c);
            if (it != curr->children.end()) {
                curr = it->second;
                prefix += curr->value;
            }
            else {
                curr = nullptr;
                return {};
            }
        }
        vector<string> result = completeWord(curr, prefix);
        return result;
    }

    vector<string> completeWord(TrieNode* node, string& prefix) {
        vector<string> result;
        string bt;
        dfs(node, prefix, bt, result);
        return result;
    }

    void dfs(TrieNode* node, string& prefix, string bt, vector<string>& result) {
        bt += node->value;
        if (node->value == 0) {
            if (bt.size() > 0) {
                result.push_back(prefix + bt.substr(1, bt.size() - 1));
            }
            return;
        }
        for (auto n : node->children) {
            dfs(n.second, prefix, bt, result);
            if (result.size() == 3) {
                return;
            }
        }
    }
};

class Solution {
public:
    vector<vector<string>> suggestedProducts(vector<string>& products, string searchWord) {
        Trie trie;
        for (auto w : products) {
            trie.build(w);
        }
        vector<vector<string>> ans;
        for (int i = 1; i <= searchWord.size(); i++) {
            ans.push_back(trie.search(searchWord.substr(0, i)));
        }
        return ans;
    }
};
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