<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 Solution {
public:
    class TrieNode {
    public:
        char data;
        TrieNode* children[26];
        bool isTerminal;

        TrieNode(char d) {
            this->data = d;
            for (int i = 0; i < 26; i++) {
                children[i] = nullptr;
            }
            this->isTerminal = false;
        }
    };

    TrieNode* root;

    Solution() {
        root = new TrieNode('\0'); // Initialize root with a dummy character
    }

    void insertWord(TrieNode* root, const string& word) {
        // Base case
        if (word.length() == 0) {
            root->isTerminal = true;
            return;
        }

        char ch = word[0];
        int index = ch - 'a';
        TrieNode* child;

        // Check if the character node exists
        if (root->children[index] != nullptr) {
            child = root->children[index];
        } else {
            // Create a new TrieNode if not present
            child = new TrieNode(ch);
            root->children[index] = child;
        }

        // Recursive call for the next part of the word
        insertWord(child, word.substr(1));
    }

    bool searchWord(TrieNode* root, const string& word) {
        // Base case: if the word is empty, check if the current node is terminal
        if (word.length() == 0)
            return root->isTerminal;

        char ch = word[0];
        int index = ch - 'a'; // Changed to 'a' since input is in lowercase
        TrieNode* child;

        // If the character node exists, continue searching
        if (root->children[index] != nullptr) {
            child = root->children[index];
        } else {
            // If the character node doesn't exist, the word is not in the trie
            return false;
        }

        // Recursive call for the next part of the word
        return searchWord(child, word.substr(1));
    }

    void storeSuggestion(TrieNode* curr, vector<string>& temp, string& prefix, int limit = 3) {
        if (curr->isTerminal) {
            temp.push_back(prefix);
            if (temp.size() == limit) return;
        }

        // Explore all possible children from 'a' to 'z'
        for (char ch = 'a'; ch <= 'z'; ch++) {
            int index = ch - 'a';
            TrieNode* next = curr->children[index];
            if (next != nullptr) {
                // If a valid child exists, add it to the prefix and explore further
                prefix.push_back(ch);
                storeSuggestion(next, temp, prefix, limit);
                // Backtrack by removing the last character added to the prefix
                prefix.pop_back();
                if (temp.size() == limit) return; // Stop if we've already collected enough suggestions
            }
        }
    }

    vector<vector<string>> suggestedProducts(vector<string>& products, const string& searchWord) {
        // Insert all products into the Trie
        for (const string& product : products) {
            insertWord(root, product);
        }

        TrieNode* prev = root;
        vector<vector<string>> output;
        string prefix = "";

        // Iterate through each character of the searchWord
        for (int i = 0; i < searchWord.length(); i++) {
            char lastCh = searchWord[i];
            int index = lastCh - 'a';
            TrieNode* curr = prev->children[index];

            // If no children exist for the current character, break out of the loop
            if (curr == nullptr) {
                break;
            } else {
                // Otherwise, continue storing suggestions
                vector<string> temp;
                prefix.push_back(lastCh);
                storeSuggestion(curr, temp, prefix);
                output.push_back(temp);
                prev = curr;
            }
        }

        // In case the prefix becomes shorter than searchWord, fill the remaining with empty vectors
        while (output.size() < searchWord.size()) {
            output.push_back({});
        }

        return output;
    }
};

92930