* Dynamic Programming and the related concept of Memoization. * Recursion - most complex problems seem to have a recursive solution which you can actually impl

* Dynamic Programming and the related concept of Memoization. * Recursion - most complex problems seem to have a recursive solution which you can actually implement in a language like Scheme or Haskell that does not limit stack size. * State machines. * Monte Carlo methods. * Unification - see SICP. * Hand-rolled parsers instead of regular expressions for debug-ability and readability.