<p>Given an array of <strong>distinct</strong> integers <code>arr</code>, find all pairs of elements with the minimum absolute difference of any two elements.</p>
<p>Return a list of pairs in ascending order(with respect to pairs), each pair <code>[a, b]</code> follows</p>
<ul>
<li><code>a, b</code> are from <code>arr</code></li>
<li><code>a < b</code></li>
<li><code>b - a</code> equals to the minimum absolute difference of any two elements in <code>arr</code></li>