https://www.michelebologna.net/tags/heap/ Recent content in Heap on Michele Bologna Hugo en Tue, 02 Feb 2016 00:00:00 +0000 https://www.michelebologna.net/2016/spotify-puzzles-round-two/ Tue, 02 Feb 2016 00:00:00 +0000 https://www.michelebologna.net/2016/spotify-puzzles-round-two/ <p>Some months ago, <a href="https://www.michelebologna.net/2015/05/spotify-puzzles-round-one/" class="external-link" target="_blank" rel="noopener">I began challenging myself with <strong>Spotify puzzles</strong></a>: at that time I was dealing with an easy problem; now, the difficulty has increased. The round two consists in the typical &ldquo;<em><a href="https://en.wikipedia.org/wiki/Selection_algorithm" class="external-link" target="_blank" rel="noopener">Selection problem</a></em>&rdquo;: given an array of values, find the max (or min) <code>k</code> values. I decided to still use Python and to use its <strong>heapq</strong> module to store values in a binary max-heap data structure, and then remove exactly <code>k</code> values from the top of the heap. This approach will guarantee that the total time complexity of the algorithm will be <code>O(n log k)</code>.</p>