<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> common(26,INT_MAX);
    vector<string> res;

    for (auto s : words){
        vector<int> cnt(26, 0);
        for (auto c : s)
            cnt[c - 'a']++;
        for (auto i = 0; i < 26; i++)
            common[i] = min(common[i], cnt[i]);
    }

    for (auto i = 0; i < 26; i++)
        for (auto j = 0; j < common[i]; j++)
            res.push_back(string(1, i + 'a'));
        
    return res;
}
};
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