Implement quick sort in ruby

quick_sort.rb

# Algorithms: https://www.geeksforgeeks.org/quick-sort/

  def quick_sort(array)
    return array if array.length <= 1

    pivot = array.pop
    l = -1
    for i in 0...array.length
      next unless array[i] < pivot

      l += 1
      array[i], array[l] = array[l], array[i] if l != i
    end

    print "#{array} \n"
    if l == -1
      [pivot] + quick_sort(array[0..l])
    else
      quick_sort(array[0..l]) + [pivot] + quick_sort(array[(l + 1)..-1])
    end
  end

  def quick_sort_c2(array)
    return array if array.length <= 1

    pivot = array.pop
    left = []
    right = []

    for i in 0...array.length
      if array[i] < pivot
        left << array[i]
      else
        right << array[i]
      end
    end

    print "#{array} \n"
    quick_sort(left) + [pivot] + quick_sort(right)
  end
  
  
puts '------------------------------QUICK SORT SORT O(nlogn)--------------------------'
arr = [3,7,8,4,10,16,2,1,12]
print quick_sort(arr)
print quick_sort_c2(arr)