<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<string> res;
        if(words.size() == 0) return res;
        int hash[26] = {0};

        for(int i=0; i<words[0].size(); i++){
            hash[words[0][i]-'a']++;
        }

        
        for(int i=1; i<words.size(); i++){
            // memset(has1, 0, 26*sizeof(int));
            int hash1[26] = {0};
            for(int j=0; j<words[i].size(); j++){
                hash1[words[i][j]-'a']++;
            }

            for(int k=0; k<26; k++){
                hash[k] = min(hash[k], hash1[k]);
            }
        }

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

        return res;

    }
};
11500