<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:
    vector<vector<string>> suggestedProducts(vector<string>& products,
                                             string searchWord) {
        // We can create a map of strings / substrings that point to a list of
        // words with our key as the prefix. e.g. WordMap['A'] = ["And",
        // "Anduril", "Andersen", "Abigail"] WordMap["And"] = ["And", "Anduril",
        // "Andersen"] -> WordMap["Andu"] -> ["Anduril"] then find first 3 in
        // list based on suggestion

        // slightly expensive to create our map
        // Populate our word / product map
        unordered_map<string, vector<string>> wordMap{};
        for (auto product : products) {
            for (int i = 1; i <= product.size(); i++) {
                // Get our prefix
                string prefix = product.substr(0, i);
                // If our prefix is in our word map already, add our word to the
                // list of possible words with that prefix
                if (wordMap.contains(prefix)) {
                    wordMap[prefix].push_back(product);
                }
                // Other wise create a new vector of words
                else {
                    wordMap[prefix] = {product};
                }
            }
        }

        // Create a list of list of words, with each index representing 3
        // possible words for the given number of characters of our search word
        vector<vector<string>> productList{};
        for (int i = 1; i <= searchWord.size(); i++) {
            string prefix = searchWord.substr(0, i);
            if (wordMap.contains(prefix)){
                sort(wordMap[prefix].begin(), wordMap[prefix].end());
                vector<string> possibleWords = wordMap[prefix];
                if (possibleWords.size() > 3) {
                    productList.push_back(
                        {possibleWords[0], possibleWords[1], possibleWords[2]});
                } else {
                    productList.push_back(possibleWords);
                }
            } else {
                productList.push_back({});
            }
        }

        return productList;
    }
};
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