





"""simple docstring"""
from typing import Any







class       a							:



 def __init__(     self				,       _snake_case     ):







  """simple docstring"""






  lowerCAmelCase    				= data
  lowerCAmelCase    				= None



 def __repr__(     self     ):







  """simple docstring"""






  return F'Node({self.data})'







class       a							:



 def __init__(     self     ):







  """simple docstring"""






  lowerCAmelCase    				= None



 def __iter__(     self     ):







  """simple docstring"""






  lowerCAmelCase    				= self.head
  while node:
   yield node.data
   lowerCAmelCase    				= node.next



 def __len__(     self     ):







  """simple docstring"""






  return sum(1 for _ in self     )



 def __repr__(     self     ):







  """simple docstring"""






  return "->".join([str(_snake_case     ) for item in self]     )



 def __getitem__(     self				,       _snake_case     ):







  """simple docstring"""






  if not 0 <= index < len(self     ):
   raise ValueError('list index out of range.'     )
  for i, node in enumerate(self     ):
   if i == index:
    return node
  return None



 def __setitem__(     self				,       _snake_case				,       _snake_case     ):







  """simple docstring"""






  if not 0 <= index < len(self     ):
   raise ValueError('list index out of range.'     )
  lowerCAmelCase    				= self.head
  for _ in range(_snake_case     ):
   lowerCAmelCase    				= current.next
  lowerCAmelCase    				= data



 def    UpperCamelCase__  (     self				,       _snake_case     ):







  """simple docstring"""






  self.insert_nth(len(self     )				,       _snake_case     )



 def    UpperCamelCase__  (     self				,       _snake_case     ):







  """simple docstring"""






  self.insert_nth(0				,       _snake_case     )



 def    UpperCamelCase__  (     self				,       _snake_case				,       _snake_case     ):







  """simple docstring"""






  if not 0 <= index <= len(self     ):
   raise IndexError('list index out of range'     )
  lowerCAmelCase    				= Node(_snake_case     )
  if self.head is None:
   lowerCAmelCase    				= new_node
  elif index == 0:
   lowerCAmelCase    				= self.head  # link new_node to head
   lowerCAmelCase    				= new_node
  else:
   lowerCAmelCase    				= self.head
   for _ in range(index - 1     ):
    lowerCAmelCase    				= temp.next
   lowerCAmelCase    				= temp.next
   lowerCAmelCase    				= new_node



 def    UpperCamelCase__  (     self     ):  # print every node data







  """simple docstring"""






  print(self     )



 def    UpperCamelCase__  (     self     ):







  """simple docstring"""






  return self.delete_nth(0     )



 def    UpperCamelCase__  (     self     ):  # delete from tail







  """simple docstring"""






  return self.delete_nth(len(self     ) - 1     )



 def    UpperCamelCase__  (     self				,       _snake_case = 0     ):







  """simple docstring"""






  if not 0 <= index <= len(self     ) - 1:  # test if index is valid
   raise IndexError('List index out of range.'     )
  lowerCAmelCase    				= self.head  # default first node
  if index == 0:
   lowerCAmelCase    				= self.head.next
  else:
   lowerCAmelCase    				= self.head
   for _ in range(index - 1     ):
    lowerCAmelCase    				= temp.next
   lowerCAmelCase    				= temp.next
   lowerCAmelCase    				= temp.next.next
  return delete_node.data



 def    UpperCamelCase__  (     self     ):







  """simple docstring"""






  return self.head is None



 def    UpperCamelCase__  (     self     ):







  """simple docstring"""






  lowerCAmelCase    				= None
  lowerCAmelCase    				= self.head

  while current:
   # Store the current node's next node.
   lowerCAmelCase    				= current.next
   # Make the current node's next point backwards
   lowerCAmelCase    				= prev
   # Make the previous node be the current node
   lowerCAmelCase    				= current
   # Make the current node the next node (to progress iteration)
   lowerCAmelCase    				= next_node
  # Return prev in order to put the head at the end
  lowerCAmelCase    				= prev


def 		_SCREAMING_SNAKE_CASE			():
 lowerCAmelCase    				= LinkedList()
 assert linked_list.is_empty() is True
 assert str(_UpperCAmelCase			) == ""

 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(_UpperCAmelCase			) == i
  linked_list.insert_nth(_UpperCAmelCase  ,     i + 1			)
 assert str(_UpperCAmelCase			) == "->".join(str(_UpperCAmelCase			) for i in range(1  ,     11			)			)

 linked_list.insert_head(0			)
 linked_list.insert_tail(11			)
 assert str(_UpperCAmelCase			) == "->".join(str(_UpperCAmelCase			) for i in range(0  ,     12			)			)

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

 assert all(linked_list[i] == i + 1 for i in range(0  ,     9			)			) is True

 for i in range(0  ,     9			):
  lowerCAmelCase    				= -i
 assert all(linked_list[i] == -i for i in range(0  ,     9			)			) is True

 linked_list.reverse()
 assert str(_UpperCAmelCase			) == "->".join(str(_UpperCAmelCase			) for i in range(-8  ,     1			)			)

def 		_SCREAMING_SNAKE_CASE			():
 lowerCAmelCase    				= [
     -9,
     100,
     Node(7734_5112			),
     'dlrow olleH',
     7,
     5555,
     0,
     -192.5_5555,
     'Hello, world!',
     77.9,
     Node(10			),
     None,
     None,
     12.20,
 ]
 lowerCAmelCase    				= LinkedList()

 for i in test_input:
  linked_list.insert_tail(_UpperCAmelCase			)

 # Check if it's empty or not
 assert linked_list.is_empty() is False
 assert (
     str(_UpperCAmelCase			) == "-9->100->Node(77345112)->dlrow olleH->7->5555->0->"
     "-192.55555->Hello, world!->77.9->Node(10)->None->None->12.2"
 )

 # Delete the head
 lowerCAmelCase    				= linked_list.delete_head()
 assert result == -9
 assert (
     str(_UpperCAmelCase			) == "100->Node(77345112)->dlrow olleH->7->5555->0->-192.55555->"
     "Hello, world!->77.9->Node(10)->None->None->12.2"
 )

 # Delete the tail
 lowerCAmelCase    				= linked_list.delete_tail()
 assert result == 12.2
 assert (
     str(_UpperCAmelCase			) == "100->Node(77345112)->dlrow olleH->7->5555->0->-192.55555->"
     "Hello, world!->77.9->Node(10)->None->None"
 )

 # Delete a node in specific location in linked list
 lowerCAmelCase    				= linked_list.delete_nth(10			)
 assert result is None
 assert (
     str(_UpperCAmelCase			) == "100->Node(77345112)->dlrow olleH->7->5555->0->-192.55555->"
     "Hello, world!->77.9->Node(10)->None"
 )

 # Add a Node instance to its head
 linked_list.insert_head(Node('Hello again, world!'			)			)
 assert (
     str(_UpperCAmelCase			)
     == "Node(Hello again, world!)->100->Node(77345112)->dlrow olleH->"
     "7->5555->0->-192.55555->Hello, world!->77.9->Node(10)->None"
 )

 # Add None to its tail
 linked_list.insert_tail(_UpperCAmelCase			)
 assert (
     str(_UpperCAmelCase			)
     == "Node(Hello again, world!)->100->Node(77345112)->dlrow olleH->"
     "7->5555->0->-192.55555->Hello, world!->77.9->Node(10)->None->None"
 )

 # Reverse the linked list
 linked_list.reverse()
 assert (
     str(_UpperCAmelCase			)
     == "None->None->Node(10)->77.9->Hello, world!->-192.55555->0->5555->"
     "7->dlrow olleH->Node(77345112)->100->Node(Hello again, world!)"
 )

def 		_SCREAMING_SNAKE_CASE			():
 from doctest import testmod

 testmod()

 lowerCAmelCase    				= LinkedList()
 linked_list.insert_head(input('Inserting 1st at head '			).strip()			)
 linked_list.insert_head(input('Inserting 2nd at head '			).strip()			)
 print('\nPrint list:'			)
 linked_list.print_list()
 linked_list.insert_tail(input('\nInserting 1st at tail '			).strip()			)
 linked_list.insert_tail(input('Inserting 2nd at tail '			).strip()			)
 print('\nPrint list:'			)
 linked_list.print_list()
 print('\nDelete head'			)
 linked_list.delete_head()
 print('Delete tail'			)
 linked_list.delete_tail()
 print('\nPrint list:'			)
 linked_list.print_list()
 print('\nReverse linked list'			)
 linked_list.reverse()
 print('\nPrint list:'			)
 linked_list.print_list()
 print('\nString representation of linked list:'			)
 print(_UpperCAmelCase			)
 print('\nReading/changing Node data using indexing:'			)
 print(F'Element at Position 1: {linked_list[1]}'			)
 lowerCAmelCase    				= input('Enter New Value: '			).strip()
 print('New list:'			)
 print(_UpperCAmelCase			)
 print(F'length of linked_list is : {len(_UpperCAmelCase			)}'			)


if __name__ == "__main__":
       main()












'''simple docstring'''




from __future__ import annotations

a__					:			Optional[int]          =     list[tuple[int, int]]

a__					:			List[Any]          =     [
    [0, 0, 0, 0, 0, 0, 0],
    [0, 1, 0, 0, 0, 0, 0],  # 0 are free path whereas 1's are obstacles
    [0, 0, 0, 0, 0, 0, 0],
    [0, 0, 1, 0, 0, 0, 0],
    [1, 0, 1, 0, 0, 0, 0],
    [0, 0, 0, 0, 0, 0, 0],
    [0, 0, 0, 0, 1, 0, 0],
]

a__					:			Optional[int]          =     ([-1, 0], [0, -1], [1, 0], [0, 1])  # up, left, down, right






class 				__snake_case     :





	def __init__(		self      ,       UpperCamelCase_      ,       UpperCamelCase_      ,       UpperCamelCase_      ,       UpperCamelCase_      ,       UpperCamelCase_      ,       UpperCamelCase_      ,       )      ->		Any:
		snake_case__	       =   pos_x
		snake_case__	       =   pos_y
		snake_case__	       =   (pos_y, pos_x)
		snake_case__	       =   goal_x
		snake_case__	       =   goal_y
		snake_case__	       =   g_cost
		snake_case__	       =   parent
		snake_case__	       =   self.calculate_heuristic()





	def   _snake_case   (		self		)      ->		float:
		snake_case__	       =   abs(self.pos_x - self.goal_x		)
		snake_case__	       =   abs(self.pos_y - self.goal_y		)
		return dx + dy





	def __lt__(		self      ,       UpperCamelCase_		)      ->		bool:
		return self.f_cost < other.f_cost






class 				__snake_case     :





	def __init__(		self      ,       UpperCamelCase_      ,       UpperCamelCase_		)      ->		Any:
		snake_case__	       =   Node(start[1]      ,       start[0]      ,       goal[1]      ,       goal[0]      ,       0      ,       UpperCamelCase_		)
		snake_case__	       =   Node(goal[1]      ,       goal[0]      ,       goal[1]      ,       goal[0]      ,       9_9999      ,       UpperCamelCase_		)

		snake_case__	       =   [self.start]
		snake_case__	       =   []

		snake_case__	       =   False





	def   _snake_case   (		self		)      ->		Path | None:
		while self.open_nodes:
			# Open Nodes are sorted using __lt__
			self.open_nodes.sort()
			snake_case__	       =   self.open_nodes.pop(0		)

			if current_node.pos == self.target.pos:
				snake_case__	       =   True
				return self.retrace_path(UpperCamelCase_		)

			self.closed_nodes.append(UpperCamelCase_		)
			snake_case__	       =   self.get_successors(UpperCamelCase_		)

			for child_node in successors:
				if child_node in self.closed_nodes:
					continue

				if child_node not in self.open_nodes:
					self.open_nodes.append(UpperCamelCase_		)
				else:
					# retrieve the best current path
					snake_case__	       =   self.open_nodes.pop(self.open_nodes.index(UpperCamelCase_		)		)

					if child_node.g_cost < better_node.g_cost:
						self.open_nodes.append(UpperCamelCase_		)
					else:
						self.open_nodes.append(UpperCamelCase_		)

		if not self.reached:
			return [self.start.pos]
		return None





	def   _snake_case   (		self      ,       UpperCamelCase_		)      ->		list[Node]:
		snake_case__	       =   []
		for action in delta:
			snake_case__	       =   parent.pos_x + action[1]
			snake_case__	       =   parent.pos_y + action[0]

			if not (0 <= pos_x <= len(grid[0]		) - 1 and 0 <= pos_y <= len(UpperCamelCase_		) - 1):
				continue

			if grid[pos_y][pos_x] != 0:
				continue

			successors.append(
			    Node(
			        UpperCamelCase_      ,       UpperCamelCase_      ,       self.target.pos_y      ,       self.target.pos_x      ,       parent.g_cost + 1      ,       UpperCamelCase_      ,       )		)
		return successors





	def   _snake_case   (		self      ,       UpperCamelCase_		)      ->		Path:
		snake_case__	       =   node
		snake_case__	       =   []
		while current_node is not None:
			path.append((current_node.pos_y, current_node.pos_x)		)
			snake_case__	       =   current_node.parent
		path.reverse()
		return path


if __name__ == "__main__":
			a__					:			List[str]          =     (0, 0)
			a__					:			Dict          =     (len(grid) - 1, len(grid[0]) - 1)
			for elem in grid:
						print(elem)

			print('''------''')

			a__					:			Optional[int]          =     GreedyBestFirst(init, goal)
			a__					:			Optional[int]          =     greedy_bf.search()
			if path:
						for pos_x, pos_y in path:
									a__					:			Tuple          =     2

						for elem in grid:
									print(elem)



