




'''simple docstring'''


from __future__ import annotations

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






class 	lowerCAmelCase_  :







  '''simple docstring'''

  UpperCamelCase_ :			Optional[Any]        =							("""_front""", """_back""", """_len""")






  @dataclass
  class 	lowerCAmelCase_  :







    '''simple docstring'''

    UpperCamelCase_ :			Any        =							None
    UpperCamelCase_ :			Deque._Node | None        =							None
    UpperCamelCase_ :			Deque._Node | None        =							None






  class 	lowerCAmelCase_  :







    '''simple docstring'''

    UpperCamelCase_ :			str        =							("""_cur""",)



    def __init__(   self							:       int				,     SCREAMING_SNAKE_CASE_							:       Deque._Node | None  ) ->		None:







         '''simple docstring'''



         A:		Optional[int]        =		cur



    def __iter__(   self							:       Optional[int]  ) ->		Deque._Iterator:







         '''simple docstring'''



         return self




    def 				_snake_case    (   self							:       str  ) ->		Any:







         '''simple docstring'''



         if self._cur is None:
              # finished iterating
              raise StopIteration
         A:		List[Any]        =		self._cur.val
         A:		Tuple        =		self._cur.next_node

         return val






  def __init__(   self							:       str				,     SCREAMING_SNAKE_CASE_							:       Iterable[Any] | None = None  ) ->		None:







       '''simple docstring'''



       A:		Any        =		None
       A:		Any        =		None
       A:		int        =		0

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



  def 				_snake_case    (   self							:       Tuple				,     SCREAMING_SNAKE_CASE_							:       Any  ) ->		None:







       '''simple docstring'''



       A:		str        =		self._Node(SCREAMING_SNAKE_CASE_				,     SCREAMING_SNAKE_CASE_				,     SCREAMING_SNAKE_CASE_  )
       if self.is_empty():
            # front = back
            A:		int        =		node
            A:		Any        =		1
       else:
            # connect nodes
            A:		Optional[Any]        =		node
            A:		str        =		self._back
            A:		List[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 				_snake_case    (   self							:       Any				,     SCREAMING_SNAKE_CASE_							:       Any  ) ->		None:







       '''simple docstring'''



       A:		str        =		self._Node(SCREAMING_SNAKE_CASE_				,     SCREAMING_SNAKE_CASE_				,     SCREAMING_SNAKE_CASE_  )
       if self.is_empty():
            # front = back
            A:		int        =		node
            A:		str        =		1
       else:
            # connect nodes
            A:		Union[str, Any]        =		self._front
            A:		Union[str, Any]        =		node
            A:		str        =		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 				_snake_case    (   self							:       int				,     SCREAMING_SNAKE_CASE_							:       Iterable[Any]  ) ->		None:







       '''simple docstring'''



       for val in iterable:
            self.append(SCREAMING_SNAKE_CASE_  )



  def 				_snake_case    (   self							:       List[str]				,     SCREAMING_SNAKE_CASE_							:       Iterable[Any]  ) ->		None:







       '''simple docstring'''



       for val in iterable:
            self.appendleft(SCREAMING_SNAKE_CASE_  )



  def 				_snake_case    (   self							:       List[Any]  ) ->		Any:







       '''simple docstring'''



       assert not self.is_empty(), "Deque is empty."

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

       self._len -= 1

       return topop.val



  def 				_snake_case    (   self							:       Any  ) ->		Any:







       '''simple docstring'''



       assert not self.is_empty(), "Deque is empty."

       A:		Optional[Any]        =		self._front
       A:		Optional[int]        =		self._front.next_node  # set new front and drop the first node
       A:		Dict        =		None

       self._len -= 1

       return topop.val



  def 				_snake_case    (   self							:       Union[str, Any]  ) ->		bool:







       '''simple docstring'''



       return self._front is None



  def __len__(   self							:       Tuple  ) ->		int:







       '''simple docstring'''



       return self._len



  def __eq__(   self							:       List[Any]				,     SCREAMING_SNAKE_CASE_							:       object  ) ->		bool:







       '''simple docstring'''



       if not isinstance(SCREAMING_SNAKE_CASE_				,     SCREAMING_SNAKE_CASE_  ):
            return NotImplemented

       A:		Any        =		self._front
       A:		int        =		other._front

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

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

       return True



  def __iter__(   self							:       List[Any]  ) ->		Deque._Iterator:







       '''simple docstring'''



       return Deque._Iterator(self._front  )




  def __repr__(   self							:       List[str]  ) ->		str:







       '''simple docstring'''



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

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


if __name__ == "__main__":
     import doctest

     doctest.testmod()












'''simple docstring'''


def 				SCREAMING_SNAKE_CASE(      __lowercase		,							__lowercase		,							__lowercase  ) ->   float:
     A:		str        =		[1 / first_term]
     A:		Optional[int]        =		1 / first_term
     for _ in range(number_of_terms - 1  ):
          first_term += common_difference
          arithmetic_progression.append(__lowercase  )
     A:		int        =		[1 / step for step in arithmetic_progression]
     return sum(__lowercase  )


if __name__ == "__main__":
     import doctest

     doctest.testmod()
     print(sum_of_harmonic_progression(1 / 2, 2, 2))






