Create cyclic_sort.py (#9256)

* Create cyclic_sort.py * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * Update cyclic_sort.py * updating DIRECTORY.md * Update cyclic_sort.py * Update cyclic_sort.py * Update cyclic_sort.py * Update cyclic_sort.py * Update cyclic_sort.py --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com> Co-authored-by: Maxim Smolskiy <mithridatus@mail.ru> Co-authored-by: MaximSmolskiy <MaximSmolskiy@users.noreply.github.com>

Author: 3 people

DIRECTORY.md

@@ -1267,6 +1267,7 @@
  * [Comb Sort](sorts/comb_sort.py)
  * [Counting Sort](sorts/counting_sort.py)
  * [Cycle Sort](sorts/cycle_sort.py)
+ * [Cyclic Sort](sorts/cyclic_sort.py)
  * [Double Sort](sorts/double_sort.py)
  * [Dutch National Flag Sort](sorts/dutch_national_flag_sort.py)
  * [Exchange Sort](sorts/exchange_sort.py)

sorts/cyclic_sort.py

@@ -0,0 +1,55 @@
+"""
+This is a pure Python implementation of the Cyclic Sort algorithm.
+
+For doctests run following command:
+python -m doctest -v cyclic_sort.py
+or
+python3 -m doctest -v cyclic_sort.py
+For manual testing run:
+python cyclic_sort.py
+or
+python3 cyclic_sort.py
+"""
+
+
+def cyclic_sort(nums: list[int]) -> list[int]:
+ """
+ Sorts the input list of n integers from 1 to n in-place
+ using the Cyclic Sort algorithm.
+
+ :param nums: List of n integers from 1 to n to be sorted.
+ :return: The same list sorted in ascending order.
+
+ Time complexity: O(n), where n is the number of integers in the list.
+
+ Examples:
+ >>> cyclic_sort([])
+ []
+ >>> cyclic_sort([3, 5, 2, 1, 4])
+ [1, 2, 3, 4, 5]
+ """
+
+ # Perform cyclic sort
+ index = 0
+ while index < len(nums):
+ # Calculate the correct index for the current element
+ correct_index = nums[index] - 1
+ # If the current element is not at its correct position,
+ # swap it with the element at its correct index
+ if index != correct_index:
+ nums[index], nums[correct_index] = nums[correct_index], nums[index]
+ else:
+ # If the current element is already in its correct position,
+ # move to the next element
+ index += 1
+
+ return nums
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()
+ user_input = input("Enter numbers separated by a comma:\n").strip()
+ unsorted = [int(item) for item in user_input.split(",")]
+ print(*cyclic_sort(unsorted), sep=",")