<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>

struct Node {
    Node* links[26];
    bool flag = false;
    Node() {
        for (int i = 0; i < 26; i++) {
            links[i] = nullptr;
        }
    }
};

class Trie {
public:
    Node* root;
    Trie() {
        root = new Node();
    }
    void insert(string s) {
        Node* node = root;
        for (auto it : s) {
            if (node->links[it - 'a'] != nullptr) {
                node = node->links[it - 'a'];
            } else {
                node->links[it - 'a'] = new Node();
                node = node->links[it - 'a'];
            }
        }
        node->flag = true;
    }
    vector<string> f(string word) {
        Node* node = root;
        priority_queue<string, vector<string>, greater<string>> pq;
        for (auto it : word) {
            if (node->links[it - 'a'] == nullptr) {
                return {}; // Prefix not found
            }
            node = node->links[it - 'a'];
        }
        f(node, pq, word);
        vector<string> res;
        while (!pq.empty()) {
            res.push_back(pq.top());
            pq.pop();
        }
        return res;
    }

    void f(Node* root, priority_queue<string, vector<string>, greater<string>>& pq, string word) {
        if (root->flag == true) {
            if(pq.size()>3){
                if(pq.top()>word){
                     pq.push(word);
                }
            }else{
                pq.push(word);
            }
           
        }
        for (int i = 0; i < 26; i++) {
            if (root->links[i] != nullptr) {
                char res = i + 'a';
                f(root->links[i], pq, word + res);
            }
        }
    }
};

class Solution {
public:
    vector<vector<string>> suggestedProducts(vector<string>& products, string searchWord) {
        Trie tr;
        for (auto it : products) {
            tr.insert(it);
        }
        vector<vector<string>> result;
        string prefix = "";
        for (char c : searchWord) {
            prefix += c;
            vector<string> suggestions = tr.f(prefix);
            if (suggestions.size() > 3) {
                suggestions.resize(3);
            }
            result.push_back(suggestions);
        }
        return result;
    }
};

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