Quick sort recursively in ruby

quick_sort_recursively_ruby.rb

#Author: Shubham Mishra

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

  # Choose the pivot element (for simplicity, we'll use the last element)
  pivot = arr.pop
  left = []
  right = []

  # Partition the array into two sub-arrays based on the pivot element
  arr.each do |element|
    if element <= pivot
      left << element
    else
      right << element
    end
  end

  # Recursive calls for the two sub-arrays
  sorted_left = quick_sort(left)
  sorted_right = quick_sort(right)

  # Combine the sorted sub-arrays and the pivot to form the final sorted array
  sorted_left + [pivot] + sorted_right
end

# Example usage:
arr = [10, 7, 8, 9, 1, 5]
sorted_arr = quick_sort(arr)
puts sorted_arr.join(' ')




####Now lets check code when pivot element is selected as middle element:
def quick_sort(arr)
  return arr if arr.length <= 1

  # Choose the pivot element as the middle element
  pivot_index = arr.length / 2
  pivot = arr[pivot_index]
  arr.delete_at(pivot_index)

  left = []
  right = []

  # Partition the array into two sub-arrays based on the pivot element
  arr.each do |element|
    if element <= pivot
      left << element
    else
      right << element
    end
  end

  # Recursive calls for the two sub-arrays
  sorted_left = quick_sort(left)
  sorted_right = quick_sort(right)

  # Combine the sorted sub-arrays and the pivot to form the final sorted array
  sorted_left + [pivot] + sorted_right
end

# Example usage:
arr = [10, 7, 8, 9, 1, 5]
sorted_arr = quick_sort(arr)
puts sorted_arr.join(' ')