
"""simple docstring"""


from __future__ import annotations

from collections.abc import Iterator
from typing import Any







class 					lowerCAmelCase_					:



						'''simple docstring'''


						def __init__(			self  :   Optional[Any]	,A_  :   Any   )  -> List[Any]:
							A     = data
							A     = None







class 					lowerCAmelCase_					:



						'''simple docstring'''


						def __init__(			self  :   int   )  -> List[str]:
							A     = None
							A     = None


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


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


						def __repr__(			self  :   Any   )  -> Union[str, Any]:
							return "->".join(str(A_   ) for item in iter(self   )   )


						def     _SCREAMING_SNAKE_CASE   (			self  :   List[str]	,A_  :   Any   )  -> None:
							self.insert_nth(len(self   )	,A_   )


						def     _SCREAMING_SNAKE_CASE   (			self  :   Union[str, Any]	,A_  :   Any   )  -> None:
							self.insert_nth(0	,A_   )


						def     _SCREAMING_SNAKE_CASE   (			self  :   List[Any]	,A_  :   int	,A_  :   Any   )  -> None:
							if index < 0 or index > len(self   ):
								raise IndexError('list index out of range.'   )
							A     = Node(A_   )
							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     _SCREAMING_SNAKE_CASE   (			self  :   Tuple   )  -> Union[str, Any]:
							return self.delete_nth(0   )


						def     _SCREAMING_SNAKE_CASE   (			self  :   Union[str, Any]   )  -> Any:
							return self.delete_nth(len(self   ) - 1   )


						def     _SCREAMING_SNAKE_CASE   (			self  :   Tuple	,A_  :   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     _SCREAMING_SNAKE_CASE   (			self  :   Dict   )  -> bool:
							return len(self   ) == 0






def    _snake_case					(		):
	A     = CircularLinkedList()
	assert len(snake_case__  ) == 0
	assert circular_linked_list.is_empty() is True
	assert str(snake_case__  ) == ""

	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(snake_case__  ) == i
		circular_linked_list.insert_nth(snake_case__						,   i + 1  )
	assert str(snake_case__  ) == "->".join(str(snake_case__  ) for i in range(1						,   6  )  )

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

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

	circular_linked_list.insert_nth(2						,   3  )
	assert str(snake_case__  ) == "->".join(str(snake_case__  ) 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 				__snake_case     (					__magic_name__							):





	@staticmethod
	@abstractmethod
	def   _snake_case   (		UpperCamelCase_		)      ->		Dict:
		raise NotImplementedError()





	@abstractmethod
	def   _snake_case   (		self		)      ->		List[Any]:
		raise NotImplementedError()



