<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:
    // Initialize your data structure here.
        bool isWord;
        TrieNode *children[26];
        
        TrieNode() {
            isWord = false;
            
            for (int i = 0; i < 26; i++)
                children[i] = NULL;
        }
};
class Solution {
private:
    TrieNode* root;
    void insert(string word) {
        int len = word.length();
        TrieNode* curr = root;

        for(int i=0;i<len;i++) {
            int k = word[i]-'a';
            if(curr->children[k] == nullptr) {
                curr->children[k] = new TrieNode();
            }
            curr = curr->children[k];
        }
        curr->isWord = true;
        
    }
public:
    Solution() {
        root = new TrieNode();
    }
    void suggestionsRec(TrieNode* curr, string& cp, vector<string>& t){
    // found a string in Trie with the given prefix
        if(t.size() == 3) {
            return;
        }
        if (curr->isWord) {
            t.push_back(cp);
            // return;
        }
            // cout << currPrefix << endl;
    
        for (int i = 0; i < 26; i++)
            if (curr->children[i]) {
                // child node character value
                char child = 'a' + i;
                cp+=child;
                suggestionsRec(curr->children[i],
                            cp, t);
                cp.pop_back();
            }
    }
    vector<string> autoSuggest(string q) {
        TrieNode* curr = root;

        int len = q.length();

        for(int i=0;i<len;i++) {
            int k = q[i]-'a';
            if(!curr->children[k]) return {};
            curr = curr->children[k];
        }
        vector<string> t;
        suggestionsRec(curr, q, t);
        return t;

    }
    vector<vector<string>> suggestedProducts(vector<string>& ps, string sw) {
        for(auto p: ps) {
            insert(p);
        }
        vector<vector<string>> ans;
        for(int i=0;i<sw.length();i++) {
            // cout<<sw.substr(0, i+1)<<endl;
            ans.push_back(autoSuggest(sw.substr(0, i+1)));
        }
        return ans;


        
    }
};
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