Lecture 15: Sorting
Some sorting algorithms:
O(n^2) algorithms:
  sort rest of list, insert first into it
  find maximum in list, swap it with first, resort
  bubble sort
quicksort:
  take first item in list
  partition list into items < first and items greater than first
  construct (<first) first (>first)
  recur on sub-lists
hybrid algorithms:
  different algorithms have different performance characteristics
  in different regimes -- have an algorithm that uses appropriate
  algorithms in different regimes.