




'''simple docstring'''




from typing import Literal

snake_case__      				=  """ABCDEFGHIJKLMNOPQRSTUVWXYZ"""




def   snake_case__			(       lowerCamelCase__ :      List[str]	,						lowerCamelCase__ :      Optional[int]	,						lowerCamelCase__ :      Optional[int]	)      ->      str:
					A_       :   Dict       =							LETTERS if mode == '''decrypt''' else key
					A_       :   Optional[Any]       =							key if mode == '''decrypt''' else LETTERS
					A_       :   Any       =							''''''
					# loop through each symbol in the message
					for symbol in message:
										if symbol.upper() in chars_a:
															# encrypt/decrypt the symbol
															A_       :   Optional[Any]       =							chars_a.find(symbol.upper()	)
															if symbol.isupper():
																				translated += chars_b[sym_index].upper()
															else:
																				translated += chars_b[sym_index].lower()
										else:
															# symbol is not in LETTERS, just add it
															translated += symbol
					return translated




def   snake_case__			(       lowerCamelCase__ :      int	,						lowerCamelCase__ :      Union[str, Any]	)      ->      List[Any]:
					return translate_message(_snake_case	,						_snake_case	,						'''encrypt'''	)




def   snake_case__			(       lowerCamelCase__ :      int	,						lowerCamelCase__ :      Optional[int]	)      ->      Any:
					return translate_message(_snake_case	,						_snake_case	,						'''decrypt'''	)




def   snake_case__			(       )      ->      Dict:
					A_       :   Optional[Any]       =							'''Hello World'''
					A_       :   Optional[int]       =							'''QWERTYUIOPASDFGHJKLZXCVBNM'''
					A_       :   str       =							'''decrypt'''  # set to 'encrypt' or 'decrypt'

					if mode == "encrypt":
										A_       :   str       =							encrypt_message(_snake_case	,						_snake_case	)
					elif mode == "decrypt":
										A_       :   Optional[Any]       =							decrypt_message(_snake_case	,						_snake_case	)
					print(f'Using the key {key}, the {mode}ed message is: {translated}'	)


if __name__ == "__main__":
							import doctest

							doctest.testmod()
							main()











"""simple docstring"""







from __future__ import annotations

from typing import Generic, TypeVar

_UpperCamelCase     			=  TypeVar("""T""")







class 					lowerCamelCase__					(       Generic[T] ):






    def __init__( self	,A					):
          UpperCAmelCase							=       data  # Assign data
          UpperCAmelCase							=       None  # Initialize next as null
          UpperCAmelCase							=       None  # Initialize prev as null







class 					lowerCamelCase__					(       Generic[T] ):






    def __init__( self					):
          UpperCAmelCase							=       None






    def 				_UpperCamelCase							( self	,A					):
          if self.head is None:
                UpperCAmelCase							=       Node(A					)
          else:
                UpperCAmelCase							=       Node(A					)
                UpperCAmelCase							=       new_node
                UpperCAmelCase							=       self.head
                UpperCAmelCase							=       None
                UpperCAmelCase							=       new_node






    def 				_UpperCamelCase							( self					):
          if self.head is None:
                return None
          else:
                assert self.head is not None
                UpperCAmelCase							=       self.head.data
                UpperCAmelCase							=       self.head.next
                if self.head is not None:
                      UpperCAmelCase							=       None
                return temp






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






    def __len__( self					):
          UpperCAmelCase							=       self.head
          UpperCAmelCase							=       0
          while temp is not None:
                count += 1
                UpperCAmelCase							=       temp.next
          return count






    def 				_UpperCamelCase							( self					):
          return self.head is None






    def 				_UpperCamelCase							( self					):
          print("""stack elements are:"""					)
          UpperCAmelCase							=       self.head
          while temp is not None:
                print(temp.data	,end="""->"""					)
                UpperCAmelCase							=       temp.next


# Code execution starts here
if __name__ == "__main__":
  # Start with the empty stack
  _UpperCamelCase     			=  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())



