Learn to Program, 3rd Edition

Exercises from Chapter 14

Rite of Passage: Sorting

(Found here.)

Write a sort method that takes an array and returns a sorted version of it.

How You Could Do It

def sort(arr) 
  if arr.length < 1
    arr # an empty array is already sorted
  else
    pivot = arr.pop

    smaller_elements = []
    larger_elements  = []

    arr.each do |elem|
      if elem < pivot
        smaller_elements.push(elem)
      else
        larger_elements.push(elem)
      end
    end

    smaller_sorted = sort(smaller_elements)
    larger_sorted  = sort(larger_elements )

    smaller_sorted + [pivot] + larger_sorted
  end
end

puts(sort(["can","feel","singing","like","a","can"]))

a
can
can
feel
like
singing

How I Would ...