
from typing import Any







class        lowerCAmelCase__      :

						def __init__(			self       ,							a				)					->      Dict:


								'''simple docstring'''

								_UpperCamelCase						    =	data
								_UpperCamelCase						    =	None







class        lowerCAmelCase__      :

						def __init__(			self				)					->      int:


								'''simple docstring'''

								_UpperCamelCase						    =	None

						def  A_				(			self				)					->      Any:


								'''simple docstring'''

								_UpperCamelCase						    =	self.head
								while temp is not None:
										print(temp.data       ,							end=""" """				)
										_UpperCamelCase						    =	temp.next
								print()

						def  A_				(			self       ,							a				)					->      Any:


								'''simple docstring'''

								_UpperCamelCase						    =	Node(a				)
								_UpperCamelCase						    =	self.head
								_UpperCamelCase						    =	new_node







						def  A_				(			self       ,							a       ,							a				)					->      str:


								'''simple docstring'''

								if node_data_a == node_data_a:
										return
								else:
										_UpperCamelCase						    =	self.head
										while node_a is not None and node_a.data != node_data_a:
												_UpperCamelCase						    =	node_a.next

										_UpperCamelCase						    =	self.head
										while node_a is not None and node_a.data != node_data_a:
												_UpperCamelCase						    =	node_a.next

										if node_a is None or node_a is None:
												return

										_UpperCamelCase    ,	_UpperCamelCase						    =	node_a.data, node_a.data


if __name__ == "__main__":
		lowerCamelCase__	=							LinkedList()
		for i in range(5, 0, -1):
				ll.push(i)

		ll.print_list()

		ll.swap_nodes(1, 4)
		print("After swapping")
		ll.print_list()



from __future__ import annotations


def 							__A(lowerCAmelCase						,  lowerCAmelCase						,  lowerCAmelCase						,  lowerCAmelCase						,  lowerCAmelCase						,  )		->				None:

		"""simple docstring"""






		_UpperCamelCase						    =	len(lowerCAmelCase )

		# If row is equal to the size of the board it means there are a queen in each row in
		# the current board (possible_board)
		if row == n:
				# We convert the variable possible_board that looks like this: [1, 3, 0, 2] to
				# this: ['. Q . . ', '. . . Q ', 'Q . . . ', '. . Q . ']
				boards.append([""". """ * i + """Q """ + """. """ * (n - 1 - i) for i in possible_board] )
				return

		# We iterate each column in the row to find all possible results in each row
		for col in range(lowerCAmelCase ):
				# We apply that we learned previously. First we check that in the current board
				# (possible_board) there are not other same value because if there is it means
				# that there are a collision in vertical. Then we apply the two formulas we
				# learned before:
				#
				# 45º: y - x = b or 45: row - col = b
				# 135º: y + x = b or row + col = b.
				#
				# And we verify if the results of this two formulas not exist in their variables
				# respectively.  (diagonal_right_collisions, diagonal_left_collisions)
				#
				# If any or these are True it means there is a collision so we continue to the
				# next value in the for loop.
				if (
				    col in possible_board
				    or row - col in diagonal_right_collisions
				    or row + col in diagonal_left_collisions
				):
						continue

				# If it is False we call dfs function again and we update the inputs
				depth_first_search(
				    [*possible_board, col]						,  [*diagonal_right_collisions, row - col]						,  [*diagonal_left_collisions, row + col]						,  lowerCAmelCase						,  lowerCAmelCase						,  )


def 							__A(lowerCAmelCase )		->				None:

		"""simple docstring"""






		_UpperCamelCase						    =	[]
		depth_first_search([]						,  []						,  []						,  lowerCAmelCase						,  lowerCAmelCase )

		# Print all the boards
		for board in boards:
				for column in board:
						print(lowerCAmelCase )
				print("""""" )

		print(len(lowerCAmelCase )						,  """solutions were found.""" )


if __name__ == "__main__":
		import doctest

		doctest.testmod()
		n_queens_solution(4)



