Find Common Characters
<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>
Array; Hash Table; String
function commonChars(words: string[]): string[] {
    const cnt = Array(26).fill(20000);
    const aCode = 'a'.charCodeAt(0);
    for (const w of words) {
        const t = Array(26).fill(0);
        for (const c of w) {
            t[c.charCodeAt(0) - aCode]++;
        }
        for (let i = 0; i < 26; i++) {
            cnt[i] = Math.min(cnt[i], t[i]);
        }
    }
    const ans: string[] = [];
    for (let i = 0; i < 26; i++) {
        cnt[i] && ans.push(...String.fromCharCode(i + aCode).repeat(cnt[i]));
    }
    return ans;
}
