single-number-ii.md

<p>Given a <strong>non-empty</strong>&nbsp;array of integers, every element appears <em>three</em> times except for one, which appears exactly once. Find that single one.</p>

<p><strong>Note:</strong></p>

<p>Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?</p>

<p><strong>Example 1:</strong></p>

<pre>
<strong>Input:</strong> [2,2,3,2]
<strong>Output:</strong> 3
</pre>

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

<pre>
<strong>Input:</strong> [0,1,0,1,0,1,99]
<strong>Output:</strong> 99</pre>