Reverse Words in a String II
<p>Given a character array <code>s</code>, reverse the order of the <strong>words</strong>.</p>

<p>A <strong>word</strong> is defined as a sequence of non-space characters. The <strong>words</strong> in <code>s</code> will be separated by a single space.</p>

<p>Your code must solve the problem&nbsp;<strong>in-place,</strong> i.e. without allocating extra space.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> s = ["t","h","e"," ","s","k","y"," ","i","s"," ","b","l","u","e"]
<strong>Output:</strong> ["b","l","u","e"," ","i","s"," ","s","k","y"," ","t","h","e"]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> s = ["a"]
<strong>Output:</strong> ["a"]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s[i]</code> is an English letter (uppercase or lowercase), digit, or space <code>&#39; &#39;</code>.</li>
	<li>There is <strong>at least one</strong> word in <code>s</code>.</li>
	<li><code>s</code> does not contain leading or trailing spaces.</li>
	<li>All the words in <code>s</code> are guaranteed to be separated by a single space.</li>
</ul>
Two Pointers; String
func reverseWords(s []byte) {
	reverse := func(i, j int) {
		for ; i < j; i, j = i+1, j-1 {
			s[i], s[j] = s[j], s[i]
		}
	}
	i, n := 0, len(s)
	for j, c := range s {
		if c == ' ' {
			reverse(i, j-1)
			i = j + 1
		} else if j == n-1 {
			reverse(i, j)
		}
	}
	reverse(0, n-1)
}