




from __future__ import annotations

from collections.abc import Iterator
from typing import Any




class     snake_case__							:
				"""simple docstring"""



				def __init__(      self				:     List[str]					,      __lowerCamelCase				:     Any							)					->     Union[str, Any]:
							a    =			data
							a    =			None




class     snake_case__							:
				"""simple docstring"""



				def __init__(      self				:     Tuple							)					->     List[Any]:
							a    =			None
							a    =			None





				def __iter__(      self				:     Any							)					->     Iterator[Any]:
							a    =			self.head
							while self.head:
										yield node.data
										a    =			node.next
										if node == self.head:
													break





				def __len__(      self				:     Optional[int]							)					->     int:
							return sum(1 for _ in self							)





				def __repr__(      self				:     Optional[Any]							)					->     Optional[int]:
							return "->".join(str(__lowerCamelCase							) for item in iter(self							)							)





				def 							__UpperCAmelCase							(      self				:     Union[str, Any]					,      __lowerCamelCase				:     Any							)					->     None:
							self.insert_nth(len(self							)					,      __lowerCamelCase							)





				def 							__UpperCAmelCase							(      self				:     Dict					,      __lowerCamelCase				:     Any							)					->     None:
							self.insert_nth(0					,      __lowerCamelCase							)





				def 							__UpperCAmelCase							(      self				:     List[str]					,      __lowerCamelCase				:     int					,      __lowerCamelCase				:     Any							)					->     None:
							if index < 0 or index > len(self							):
										raise IndexError("list index out of range."							)
							a    =			Node(__lowerCamelCase							)
							if self.head is None:
										a    =			new_node  # first node points itself
										a    =			a    =			new_node
							elif index == 0:  # insert at head
										a    =			self.head
										a    =			a    =			new_node
							else:
										a    =			self.head
										for _ in range(index - 1							):
													a    =			temp.next
										a    =			temp.next
										a    =			new_node
										if index == len(self							) - 1:  # insert at tail
													a    =			new_node





				def 							__UpperCAmelCase							(      self				:     List[Any]							)					->     List[str]:
							return self.delete_nth(0							)





				def 							__UpperCAmelCase							(      self				:     Optional[int]							)					->     Any:
							return self.delete_nth(len(self							) - 1							)





				def 							__UpperCAmelCase							(      self				:     Tuple					,      __lowerCamelCase				:     int = 0							)					->     Any:
							if not 0 <= index < len(self							):
										raise IndexError("list index out of range."							)
							a    =			self.head
							if self.head == self.tail:  # just one node
										a    =			a    =			None
							elif index == 0:  # delete head node
										a    =			self.tail.next.next
										a    =			self.head.next
							else:
										a    =			self.head
										for _ in range(index - 1							):
													a    =			temp.next
										a    =			temp.next
										a    =			temp.next.next
										if index == len(self							) - 1:  # delete at tail
													a    =			temp
							return delete_node.data





				def 							__UpperCAmelCase							(      self				:     str							)					->     bool:
							return len(self							) == 0




def 			__magic_name__				( ):






			'''simple docstring'''







			a    =			CircularLinkedList()
			assert len(A   ) == 0
			assert circular_linked_list.is_empty() is True
			assert str(A   ) == ""

			try:
						circular_linked_list.delete_front()
						raise AssertionError  # This should not happen
			except IndexError:
						assert True  # This should happen

			try:
						circular_linked_list.delete_tail()
						raise AssertionError  # This should not happen
			except IndexError:
						assert True  # This should happen

			try:
						circular_linked_list.delete_nth(-1   )
						raise AssertionError
			except IndexError:
						assert True

			try:
						circular_linked_list.delete_nth(0   )
						raise AssertionError
			except IndexError:
						assert True

			assert circular_linked_list.is_empty() is True
			for i in range(5   ):
						assert len(A   ) == i
						circular_linked_list.insert_nth(A,  i + 1   )
			assert str(A   ) == "->".join(str(A   ) for i in range(1,  6   )   )

			circular_linked_list.insert_tail(6   )
			assert str(A   ) == "->".join(str(A   ) for i in range(1,  7   )   )
			circular_linked_list.insert_head(0   )
			assert str(A   ) == "->".join(str(A   ) for i in range(0,  7   )   )

			assert circular_linked_list.delete_front() == 0
			assert circular_linked_list.delete_tail() == 6
			assert str(A   ) == "->".join(str(A   ) for i in range(1,  6   )   )
			assert circular_linked_list.delete_nth(2   ) == 3

			circular_linked_list.insert_nth(2,  3   )
			assert str(A   ) == "->".join(str(A   ) for i in range(1,  6   )   )

			assert circular_linked_list.is_empty() is False


if __name__ == "__main__":
		import doctest

		doctest.testmod()










"""simple docstring"""







from abc import ABC, abstractmethod
from argparse import ArgumentParser




class  UpperCamelCase_	( UpperCamelCase):

	"""simple docstring"""





	@staticmethod
	@abstractmethod
	def   UpperCAmelCase_      ( UpperCAmelCase__			:				ArgumentParser   )       ->	int:
						raise NotImplementedError()




	@abstractmethod
	def   UpperCAmelCase_      ( self			:				int   )       ->	Optional[int]:
						raise NotImplementedError()
