remove-all-adjacent-duplicates-in-string-ii.md

<p>Given a string&nbsp;<code>s</code>, a <em>k</em>&nbsp;<em>duplicate removal</em>&nbsp;consists of choosing <code>k</code>&nbsp;adjacent and equal letters from&nbsp;<code>s</code> and removing&nbsp;them causing the left and the right side of the deleted substring to concatenate together.</p>

<p>We repeatedly make <code>k</code> duplicate removals on <code>s</code> until we no longer can.</p>

<p>Return the final string after all such duplicate removals have been made.</p>

<p>It is guaranteed that the answer is unique.</p>

<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;abcd&quot;, k = 2
<strong>Output:</strong> &quot;abcd&quot;
<strong>Explanation: </strong>There&#39;s nothing to delete.</pre>

<p><strong>Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;deeedbbcccbdaa&quot;, k = 3
<strong>Output:</strong> &quot;aa&quot;
<strong>Explanation: 
</strong>First delete &quot;eee&quot; and &quot;ccc&quot;, get &quot;ddbbbdaa&quot;
Then delete &quot;bbb&quot;, get &quot;dddaa&quot;
Finally delete &quot;ddd&quot;, get &quot;aa&quot;</pre>

<p><strong>Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;pbbcggttciiippooaais&quot;, k = 2
<strong>Output:</strong> &quot;ps&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 10^5</code></li>
	<li><code>2 &lt;= k &lt;= 10^4</code></li>
	<li><code>s</code> only contains lower case English letters.</li>
</ul>