title: Which algorithms are hard to implement in functional languages?
body: <p>I'm dabbling in functional languages and I have found some algorithms (especially those that use dynamic programming) harder to write and sometimes less efficient in worst case runtime.  Is there a class of algorithms which are less efficient in functional languages with immutable variables and so side effects?  </p>
  
  <p>And is there a reference that someone can point me to that will help with the more difficult to write algorithms (maybe those optimized by shared state)?</p>
  
  <p>Thanks</p>