





'''simple docstring'''







class 					_UpperCAmelCase							:
		def __init__(						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       data
					__lowerCAmelCase      		=       None
					__lowerCAmelCase      		=       None







		def __str__(						self    ):



					'''simple docstring'''

					return f'{self.data}'





class 					_UpperCAmelCase							:
		def __init__(						self    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       None
					__lowerCAmelCase      		=       None
		def __iter__(						self    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       self.head
					while node:
								yield node.data
								__lowerCAmelCase      		=       node.next
		def __str__(						self    ):



					'''simple docstring'''

					return "->".join([str(__SCREAMING_SNAKE_CASE    ) for item in self]    )
		def __len__(						self    ):



					'''simple docstring'''

					return sum(1 for _ in self    )
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					self.insert_at_nth(0,__SCREAMING_SNAKE_CASE    )
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					self.insert_at_nth(len(self    ),__SCREAMING_SNAKE_CASE    )
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       len(self    )

					if not 0 <= index <= length:
								raise IndexError("""list index out of range"""    )
					__lowerCAmelCase      		=       Node(__SCREAMING_SNAKE_CASE    )
					if self.head is None:
								__lowerCAmelCase      		=       __lowerCAmelCase      		=       new_node
					elif index == 0:
								__lowerCAmelCase      		=       new_node
								__lowerCAmelCase      		=       self.head
								__lowerCAmelCase      		=       new_node
					elif index == length:
								__lowerCAmelCase      		=       new_node
								__lowerCAmelCase      		=       self.tail
								__lowerCAmelCase      		=       new_node
					else:
								__lowerCAmelCase      		=       self.head
								for _ in range(0,__SCREAMING_SNAKE_CASE    ):
											__lowerCAmelCase      		=       temp.next
								__lowerCAmelCase      		=       new_node
								__lowerCAmelCase      		=       temp.previous
								__lowerCAmelCase      		=       temp
								__lowerCAmelCase      		=       new_node
		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					return self.delete_at_nth(0    )
		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					return self.delete_at_nth(len(self    ) - 1    )
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       len(self    )

					if not 0 <= index <= length - 1:
								raise IndexError("""list index out of range"""    )
					__lowerCAmelCase      		=       self.head  # default first node
					if length == 1:
								__lowerCAmelCase      		=       __lowerCAmelCase      		=       None
					elif index == 0:
								__lowerCAmelCase      		=       self.head.next
								__lowerCAmelCase      		=       None
					elif index == length - 1:
								__lowerCAmelCase      		=       self.tail
								__lowerCAmelCase      		=       self.tail.previous
								__lowerCAmelCase      		=       None
					else:
								__lowerCAmelCase      		=       self.head
								for _ in range(0,__SCREAMING_SNAKE_CASE    ):
											__lowerCAmelCase      		=       temp.next
								__lowerCAmelCase      		=       temp
								__lowerCAmelCase      		=       temp.previous
								__lowerCAmelCase      		=       temp.next
					return delete_node.data
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       self.head

					while current.data != data:  # Find the position to delete
								if current.next:
											__lowerCAmelCase      		=       current.next
								else:  # We have reached the end an no value matches
											raise ValueError("""No data matching given value"""    )

					if current == self.head:
								self.delete_head()

					elif current == self.tail:
								self.delete_tail()

					else:  # Before: 1 <--> 2(current) <--> 3
								__lowerCAmelCase      		=       current.next  # 1 --> 3
								__lowerCAmelCase      		=       current.previous  # 1 <--> 3
					return data







		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					return len(self    ) == 0





def      _lowerCAmelCase		(		)      ->      None:
			__lowerCAmelCase      		=       DoublyLinkedList()
			assert linked_list.is_empty() is True
			assert str(lowercase			) == ""

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

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

			for i in range(10			):
						assert len(lowercase			) == i
						linked_list.insert_at_nth(lowercase      ,			i + 1			)
			assert str(lowercase			) == "->".join(str(lowercase			) for i in range(1      ,			11			)			)

			linked_list.insert_at_head(0			)
			linked_list.insert_at_tail(11			)
			assert str(lowercase			) == "->".join(str(lowercase			) for i in range(0      ,			12			)			)

			assert linked_list.delete_head() == 0
			assert linked_list.delete_at_nth(9			) == 10
			assert linked_list.delete_tail() == 11
			assert len(lowercase			) == 9
			assert str(lowercase			) == "->".join(str(lowercase			) for i in range(1      ,			10			)			)


if __name__ == "__main__":
	from doctest import testmod

	testmod()








'''simple docstring'''







from __future__ import annotations

from collections.abc import Iterable, Iterator
from typing import Any, Generic, TypeVar

_a      :				Dict											=					TypeVar("""T""", bound=bool)





class 					_UpperCAmelCase							(		Generic[T]     ):
		def __init__(						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       value
					__lowerCAmelCase      		=       None
					__lowerCAmelCase      		=       None
		@property
		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					return self._value







		@staticmethod
		def 						lowerCamelCase__    (						__SCREAMING_SNAKE_CASE,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					if not roota:
								return roota

					if not roota:
								return roota

					if roota.value > roota.value:
								__lowerCAmelCase		, __lowerCAmelCase      		=       roota, roota

					__lowerCAmelCase      		=       roota
					__lowerCAmelCase      		=       roota.right
					__lowerCAmelCase      		=       roota.left
					__lowerCAmelCase      		=       SkewNode.merge(__SCREAMING_SNAKE_CASE,__SCREAMING_SNAKE_CASE    )

					return result





class 					_UpperCAmelCase							(		Generic[T]     ):
		def __init__(						self,__SCREAMING_SNAKE_CASE = ()    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       None
					if data:
								for item in data:
											self.insert(__SCREAMING_SNAKE_CASE    )
		def __bool__(						self    ):



					'''simple docstring'''

					return self._root is not None
		def __iter__(						self    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       []
					while self:
								result.append(self.pop()    )

					# Pushing items back to the heap not to clear it.
					for item in result:
								self.insert(__SCREAMING_SNAKE_CASE    )

					return iter(__SCREAMING_SNAKE_CASE    )
		def 						lowerCamelCase__    (						self,__SCREAMING_SNAKE_CASE    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       SkewNode.merge(self._root,SkewNode(__SCREAMING_SNAKE_CASE    )    )
		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       self.top()
					__lowerCAmelCase      		=       (
					    SkewNode.merge(self._root.left,self._root.right    ) if self._root else None
					)

					return result
		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					if not self._root:
								raise IndexError("""Can't get top element for the empty heap."""    )
					return self._root.value







		def 						lowerCamelCase__    (						self    ):



					'''simple docstring'''

					__lowerCAmelCase      		=       None


if __name__ == "__main__":
	import doctest

	doctest.testmod()

