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
/**
 Do not return anything, modify s in-place instead.
 */
function reverseWords(s: string[]): void {
    const n = s.length;
    const reverse = (i: number, j: number): void => {
        for (; i < j; ++i, --j) {
            [s[i], s[j]] = [s[j], s[i]];
        }
    };
    for (let i = 0, j = 0; j <= n; ++j) {
        if (s[j] === ' ') {
            reverse(i, j - 1);
            i = j + 1;
        } else if (j === n - 1) {
            reverse(i, j);
        }
    }
    reverse(0, n - 1);
}
