leetcode-problemset/算法题（国外版）/divide-a-string-into-groups-of-size-k.html

<p>A string <code>s</code> can be partitioned into groups of size <code>k</code> using the following procedure:</p>

<ul>
	<li>The first group consists of the first <code>k</code> characters of the string, the second group consists of the next <code>k</code> characters of the string, and so on. Each character can be a part of <strong>exactly one</strong> group.</li>
	<li>For the last group, if the string <strong>does not</strong> have <code>k</code> characters remaining, a character <code>fill</code> is used to complete the group.</li>
</ul>

<p>Note that the partition is done so that after removing the <code>fill</code> character from the last group (if it exists) and concatenating all the groups in order, the resultant string should be <code>s</code>.</p>

<p>Given the string <code>s</code>, the size of each group <code>k</code> and the character <code>fill</code>, return <em>a string array denoting the <strong>composition of every group</strong> </em><code>s</code><em> has been divided into, using the above procedure</em>.</p>

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

<pre>
<strong>Input:</strong> s = &quot;abcdefghi&quot;, k = 3, fill = &quot;x&quot;
<strong>Output:</strong> [&quot;abc&quot;,&quot;def&quot;,&quot;ghi&quot;]
<strong>Explanation:</strong>
The first 3 characters &quot;abc&quot; form the first group.
The next 3 characters &quot;def&quot; form the second group.
The last 3 characters &quot;ghi&quot; form the third group.
Since all groups can be completely filled by characters from the string, we do not need to use fill.
Thus, the groups formed are &quot;abc&quot;, &quot;def&quot;, and &quot;ghi&quot;.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;abcdefghij&quot;, k = 3, fill = &quot;x&quot;
<strong>Output:</strong> [&quot;abc&quot;,&quot;def&quot;,&quot;ghi&quot;,&quot;jxx&quot;]
<strong>Explanation:</strong>
Similar to the previous example, we are forming the first three groups &quot;abc&quot;, &quot;def&quot;, and &quot;ghi&quot;.
For the last group, we can only use the character &#39;j&#39; from the string. To complete this group, we add &#39;x&#39; twice.
Thus, the 4 groups formed are &quot;abc&quot;, &quot;def&quot;, &quot;ghi&quot;, and &quot;jxx&quot;.
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 100</code></li>
	<li><code>s</code> consists of lowercase English letters only.</li>
	<li><code>1 &lt;= k &lt;= 100</code></li>
	<li><code>fill</code> is a lowercase English letter.</li>
</ul>