<p>Given a string array <code>words</code>, return <em>an array of all characters that show up in all strings within the </em><code>words</code><em> (including duplicates)</em>. You may return the answer in <strong>any order</strong>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> words = ["bella","label","roller"]
<strong>Output:</strong> ["e","l","l"]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> words = ["cool","lock","cook"]
<strong>Output:</strong> ["c","o"]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= words.length &lt;= 100</code></li>
	<li><code>1 &lt;= words[i].length &lt;= 100</code></li>
	<li><code>words[i]</code> consists of lowercase English letters.</li>
</ul>

class Solution {
public:
    vector<string> commonChars(vector<string>& words) {
        vector<int> ltrs(26, 101);

        for (const string& word : words) {
            int temp[26] = {0};

            for (const char& ch : word)
                temp[ch - 'a']++;

            for (int i = 0; i < 26; i++)
                ltrs[i] = min(ltrs[i], temp[i]);
        }

        vector<string> res;

        for (int i = 0; i < 26; i++) {
            while (ltrs[i]) {
                res.push_back(string(1, i + 'a'));
                ltrs[i]--;
            }
        }

        return res;
    }
};
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