kth-smallest-element-in-a-sorted-matrix.md

<p>Given a <i>n</i> x <i>n</i> matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix.</p>

<p>
Note that it is the kth smallest element in the sorted order, not the kth distinct element.
</p>

<p><b>Example:</b>
<pre>
matrix = [
   [ 1,  5,  9],
   [10, 11, 13],
   [12, 13, 15]
],
k = 8,

return 13.
</pre>
</p>

<p><b>Note: </b><br>
You may assume k is always valid, 1 &le; k &le; n<sup>2</sup>.</p>