Update cocktail_shaker_sort.py

sorts/cocktail_shaker_sort.py

@@ -1,40 +1,62 @@
-""" https://en.wikipedia.org/wiki/Cocktail_shaker_sort """
+"""
+An implementation of the cocktail shaker sort algorithm in pure Python.
 
+https://en.wikipedia.org/wiki/Cocktail_shaker_sort
+"""
 
-def cocktail_shaker_sort(unsorted: list) -> list:
+
+def cocktail_shaker_sort(arr: list[int]) -> list[int]:
  """
- Pure implementation of the cocktail shaker sort algorithm in Python.
+ Sorts a list using the Cocktail Shaker Sort algorithm.
+
+ :param arr: List of elements to be sorted.
+ :return: Sorted list.
+
  >>> cocktail_shaker_sort([4, 5, 2, 1, 2])
  [1, 2, 2, 4, 5]
-
  >>> cocktail_shaker_sort([-4, 5, 0, 1, 2, 11])
  [-4, 0, 1, 2, 5, 11]
-
  >>> cocktail_shaker_sort([0.1, -2.4, 4.4, 2.2])
  [-2.4, 0.1, 2.2, 4.4]
-
  >>> cocktail_shaker_sort([1, 2, 3, 4, 5])
  [1, 2, 3, 4, 5]
-
  >>> cocktail_shaker_sort([-4, -5, -24, -7, -11])
  [-24, -11, -7, -5, -4]
+ >>> cocktail_shaker_sort(["elderberry", "banana", "date", "apple", "cherry"])
+ ['apple', 'banana', 'cherry', 'date', 'elderberry']
+ >>> cocktail_shaker_sort((-4, -5, -24, -7, -11))
+ Traceback (most recent call last):
+ ...
+ TypeError: 'tuple' object does not support item assignment
  """
- for i in range(len(unsorted) - 1, 0, -1):
+ start, end = 0, len(arr) - 1
+
+ while start < end:
  swapped = False
 
- for j in range(i, 0, -1):
- if unsorted[j] < unsorted[j - 1]:
- unsorted[j], unsorted[j - 1] = unsorted[j - 1], unsorted[j]
+ # Pass from left to right
+ for i in range(start, end):
+ if arr[i] > arr[i + 1]:
+ arr[i], arr[i + 1] = arr[i + 1], arr[i]
  swapped = True
 
- for j in range(i):
- if unsorted[j] > unsorted[j + 1]:
- unsorted[j], unsorted[j + 1] = unsorted[j + 1], unsorted[j]
+ if not swapped:
+ break
+
+ end -= 1 # Decrease the end pointer after each pass
+
+ # Pass from right to left
+ for i in range(end, start, -1):
+ if arr[i] < arr[i - 1]:
+ arr[i], arr[i - 1] = arr[i - 1], arr[i]
  swapped = True
 
  if not swapped:
  break
- return unsorted
+
+ start += 1 # Increase the start pointer after each pass
+
+ return arr
 
 
 if __name__ == "__main__":