

"""simple docstring"""





from __future__ import annotations

from typing import Generic, TypeVar

_SCREAMING_SNAKE_CASE       :  Optional[Any]        = TypeVar("""T""")

class     __a   (      Generic[T]    ):

			"""simple docstring"""

			def __init__(							self     :					Optional[int]						,  lowercase_     :					T						):
								UpperCamelCase__		:    Any         =data  # Assign data
								UpperCamelCase__		:    Node[T] | None         =None  # Initialize next as null
								UpperCamelCase__		:    Node[T] | None         =None  # Initialize prev as null



class     __a   (      Generic[T]    ):

			"""simple docstring"""

			def __init__(							self     :					str						):
								UpperCamelCase__		:    Node[T] | None         =None






			def    _lowerCAmelCase			(							self     :					Tuple						,  lowercase_     :					T						):
								if self.head is None:
													UpperCamelCase__		:    List[str]         =Node(lowercase_						)
								else:
													UpperCamelCase__		:    Tuple         =Node(lowercase_						)
													UpperCamelCase__		:    Optional[Any]         =new_node
													UpperCamelCase__		:    Dict         =self.head
													UpperCamelCase__		:    List[str]         =None
													UpperCamelCase__		:    int         =new_node






			def    _lowerCAmelCase			(							self     :					Optional[Any]						):
								if self.head is None:
													return None
								else:
													assert self.head is not None
													UpperCamelCase__		:    int         =self.head.data
													UpperCamelCase__		:    List[str]         =self.head.next
													if self.head is not None:
																		UpperCamelCase__		:    int         =None
													return temp






			def    _lowerCAmelCase			(							self     :					Tuple						):
								return self.head.data if self.head is not None else None






			def __len__(							self     :					int						):
								UpperCamelCase__		:    List[str]         =self.head
								UpperCamelCase__		:    Optional[Any]         =0
								while temp is not None:
													count += 1
													UpperCamelCase__		:    Tuple         =temp.next
								return count






			def    _lowerCAmelCase			(							self     :					Tuple						):
								return self.head is None






			def    _lowerCAmelCase			(							self     :					Union[str, Any]						):
								print('''stack elements are:'''						)
								UpperCamelCase__		:    Tuple         =self.head
								while temp is not None:
													print(temp.data						,  end='''->'''						)
													UpperCamelCase__		:    Optional[Any]         =temp.next


# Code execution starts here
if __name__ == "__main__":
				# Start with the empty stack
				_SCREAMING_SNAKE_CASE       :  Stack[int]        = Stack()

				# Insert 4 at the beginning. So stack becomes 4->None
				print("""Stack operations using Doubly LinkedList""")
				stack.push(4)

				# Insert 5 at the beginning. So stack becomes 4->5->None
				stack.push(5)

				# Insert 6 at the beginning. So stack becomes 4->5->6->None
				stack.push(6)

				# Insert 7 at the beginning. So stack becomes 4->5->6->7->None
				stack.push(7)

				# Print the stack
				stack.print_stack()

				# Print the top element
				print("""\nTop element is """, stack.top())

				# Print the stack size
				print("""Size of the stack is """, len(stack))

				# pop the top element
				stack.pop()

				# pop the top element
				stack.pop()

				# two elements have now been popped off
				stack.print_stack()

				# Print True if the stack is empty else False
				print("""\nstack is empty:""", stack.is_empty())





"""simple docstring"""





from __future__ import annotations

from collections.abc import Iterable
from dataclasses import dataclass
from typing import Any

class     __a   :

			"""simple docstring"""

			SCREAMING_SNAKE_CASE_						     =						('_front', '_back', '_len')

			@dataclass
			class     __a   :

						"""simple docstring"""

						SCREAMING_SNAKE_CASE_						     =						None
						SCREAMING_SNAKE_CASE_						     =						None
						SCREAMING_SNAKE_CASE_						     =						None



			class     __a   :

						"""simple docstring"""

						SCREAMING_SNAKE_CASE_						     =						('_cur',)






						def __init__(							self     :					Optional[int]						,  lowercase_     :					Deque._Node | None						):
											UpperCamelCase__		:    List[str]         =cur






						def __iter__(							self     :					List[str]						):
											return self






						def    _lowerCAmelCase			(							self     :					List[Any]						):
											if self._cur is None:
																# finished iterating
																raise StopIteration
											UpperCamelCase__		:    str         =self._cur.val
											UpperCamelCase__		:    Any         =self._cur.next_node

											return val






			def __init__(							self     :					str						,  lowercase_     :					Iterable[Any] | None = None						):
								UpperCamelCase__		:    Any         =None
								UpperCamelCase__		:    Any         =None
								UpperCamelCase__		:    int         =0

								if iterable is not None:
													# append every value to the deque
													for val in iterable:
																		self.append(lowercase_						)






			def    _lowerCAmelCase			(							self     :					str						,  lowercase_     :					Any						):
								UpperCamelCase__		:    Union[str, Any]         =self._Node(lowercase_						,  lowercase_						,  lowercase_						)
								if self.is_empty():
													# front = back
													UpperCamelCase__		:    Any         =node
													UpperCamelCase__		:    List[Any]         =1
								else:
													# connect nodes
													UpperCamelCase__		:    Any         =node
													UpperCamelCase__		:    Optional[Any]         =self._back
													UpperCamelCase__		:    str         =node  # assign new back to the new node

													self._len += 1

													# make sure there were no errors
													assert not self.is_empty(), "Error on appending value."






			def    _lowerCAmelCase			(							self     :					Optional[Any]						,  lowercase_     :					Any						):
								UpperCamelCase__		:    str         =self._Node(lowercase_						,  lowercase_						,  lowercase_						)
								if self.is_empty():
													# front = back
													UpperCamelCase__		:    str         =node
													UpperCamelCase__		:    Any         =1
								else:
													# connect nodes
													UpperCamelCase__		:    int         =self._front
													UpperCamelCase__		:    int         =node
													UpperCamelCase__		:    Any         =node  # assign new front to the new node

													self._len += 1

													# make sure there were no errors
													assert not self.is_empty(), "Error on appending value."






			def    _lowerCAmelCase			(							self     :					List[Any]						,  lowercase_     :					Iterable[Any]						):
								for val in iterable:
													self.append(lowercase_						)






			def    _lowerCAmelCase			(							self     :					Dict						,  lowercase_     :					Iterable[Any]						):
								for val in iterable:
													self.appendleft(lowercase_						)






			def    _lowerCAmelCase			(							self     :					Optional[int]						):
								assert not self.is_empty(), "Deque is empty."

								UpperCamelCase__		:    List[Any]         =self._back
								UpperCamelCase__		:    Any         =self._back.prev_node  # set new back
								# drop the last node - python will deallocate memory automatically
								UpperCamelCase__		:    List[str]         =None

								self._len -= 1

								return topop.val






			def    _lowerCAmelCase			(							self     :					str						):
								assert not self.is_empty(), "Deque is empty."

								UpperCamelCase__		:    List[str]         =self._front
								UpperCamelCase__		:    List[Any]         =self._front.next_node  # set new front and drop the first node
								UpperCamelCase__		:    Dict         =None

								self._len -= 1

								return topop.val






			def    _lowerCAmelCase			(							self     :					Dict						):
								return self._front is None






			def __len__(							self     :					Any						):
								return self._len






			def __eq__(							self     :					Dict						,  lowercase_     :					object						):

								if not isinstance(lowercase_						,  lowercase_						):
													return NotImplemented

								UpperCamelCase__		:    Union[str, Any]         =self._front
								UpperCamelCase__		:    Union[str, Any]         =other._front

								# if the length of the dequeues are not the same, they are not equal
								if len(self						) != len(lowercase_						):
													return False

								while me is not None and oth is not None:
													# compare every value
													if me.val != oth.val:
																		return False
													UpperCamelCase__		:    Union[str, Any]         =me.next_node
													UpperCamelCase__		:    Union[str, Any]         =oth.next_node

								return True






			def __iter__(							self     :					Optional[int]						):
								return Deque._Iterator(self._front						)






			def __repr__(							self     :					Tuple						):
								UpperCamelCase__		:    List[Any]         =[]
								UpperCamelCase__		:    Optional[int]         =self._front
								while aux is not None:
													# append the values in a list to display
													values_list.append(aux.val						)
													UpperCamelCase__		:    Optional[Any]         =aux.next_node

								return f'''[{', '.join(repr(lowercase_						) for val in values_list						)}]'''


if __name__ == "__main__":
				import doctest

				doctest.testmod()


