Learn to Program, 2nd Edition

Exercises from Chapter 10

Rite of Passage: Sorting

How you could do it:

def sort arr
  rec_sort arr, []
end
def rec_sort unsorted, sorted
  if unsorted.length <= 0
    return sorted
  end
  #  So if we got here, then it means we still
  #  have work to do.
  smallest       = unsorted.pop
  still_unsorted = []
  unsorted.each do |tested_object|
    if tested_object < smallest
      still_unsorted.push smallest
      smallest = tested_object
    else
      still_unsorted.push tested_object
    end
  end
  #  Now "smallest" really does point to the
  #  smallest element that "unsorted" contained,
  #  and all the rest of it is in "still_unsorted".
  sorted.push smallest
  rec_sort still_unsorted, sorted
end
puts(sort(['can','feel','singing','like','a','can']))

a
can
can
feel
like ...