quick_sort.rb

def quick_sort(array, pivot=-1)
  if array.empty? || array.length == 1
    return array 
  end 
    
  slice_left = []
  slice_right = []
  pivot_slices = []
    
  array.each_index do |j|
    next if j == pivot
    slice_left << array[j] if array[j] < array[pivot]
    slice_right << array[j] if array[j] > array[pivot]
    pivot_slices << array[j] if array[j] == array[pivot]
  end
  
  p quick_sort(slice_left) + pivot_slices + [array[pivot]] + quick_sort(slice_right)
end