happy-number.md

<p>Write an algorithm to determine if a number is &quot;happy&quot;.</p>

<p>A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.</p>

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

<pre>
<strong>Input:</strong> 19
<strong>Output:</strong> true
<strong>Explanation: 
</strong>1<sup>2</sup> + 9<sup>2</sup> = 82
8<sup>2</sup> + 2<sup>2</sup> = 68
6<sup>2</sup> + 8<sup>2</sup> = 100
1<sup>2</sup> + 0<sup>2</sup> + 0<sup>2</sup> = 1
</pre>