<h2><a href="https://leetcode.com/problems/number-complement/">476. Number Complement</a></h2><h3>Easy</h3><hr><div><p>The <strong>complement</strong> of an integer is the integer you get when you flip all the <code>0</code>'s to <code>1</code>'s and all the <code>1</code>'s to <code>0</code>'s in its binary representation.</p>

<ul>
	<li>For example, The integer <code>5</code> is <code>"101"</code> in binary and its <strong>complement</strong> is <code>"010"</code> which is the integer <code>2</code>.</li>
</ul>

<p>Given an integer <code>num</code>, return <em>its complement</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre><strong>Input:</strong> num = 5
<strong>Output:</strong> 2
<strong>Explanation:</strong> The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre><strong>Input:</strong> num = 1
<strong>Output:</strong> 0
<strong>Explanation:</strong> The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.
</pre>

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

<ul>
	<li><code>1 &lt;= num &lt; 2<sup>31</sup></code></li>
</ul>

<p>&nbsp;</p>
<p><strong>Note:</strong> This question is the same as 1009: <a href="https://leetcode.com/problems/complement-of-base-10-integer/" target="_blank">https://leetcode.com/problems/complement-of-base-10-integer/</a></p>
</div>