title: Does a binary heap support the decrease-key operation?
body: <p>According to <a href="http://en.wikipedia.org/wiki/Heap_%28data_structure%29#Comparison_of_theoretic_bounds_for_variants">http://en.wikipedia.org/wiki/Heap_%28data_structure%29#Comparison_of_theoretic_bounds_for_variants</a>, it takes Θ(logn) (which translates to O(logn)) to perform the decrease-key operation. However, there seems to be no site that includes a binary heap implementation with a decrease-key operation.</p>
  
  <p>Given therefore the lack of implementations on the web, is it possible to perform the decrease-key operation in a binary heap?</p>