
def 	_SCREAMING_SNAKE_CASE					(		_lowerCamelCase :			int)					->    int:






							'''simple docstring'''





							if not head:
														return True
							# split the list to two parts
							__UpperCamelCase   ,						__UpperCamelCase	:   List[Any]			   =					head.next, head
							while fast and fast.next:
														__UpperCamelCase	:   Tuple			   =					fast.next.next
														__UpperCamelCase	:   Optional[Any]			   =					slow.next
							__UpperCamelCase	:   int			   =					slow.next
							__UpperCamelCase	:   List[Any]			   =					None  # Don't forget here! But forget still works!
							# reverse the second part
							__UpperCamelCase	:   Optional[int]			   =					None
							while second:
														__UpperCamelCase	:   int			   =					second.next
														__UpperCamelCase	:   Tuple			   =					node
														__UpperCamelCase	:   List[Any]			   =					second
														__UpperCamelCase	:   Optional[Any]			   =					nxt
							# compare two parts
							# second part has the same or one less node
							while node:
														if node.val != head.val:
																					return False
														__UpperCamelCase	:   Tuple			   =					node.next
														__UpperCamelCase	:   List[Any]			   =					head.next
							return True




def 	_SCREAMING_SNAKE_CASE					(		_lowerCamelCase :			Dict)					->    Dict:






							'''simple docstring'''





							if not head or not head.next:
														return True

							# 1. Get the midpoint (slow)
							__UpperCamelCase	:   Union[str, Any]			   =					head
							while fast and fast.next:
														__UpperCamelCase   ,						__UpperCamelCase	:   Tuple			   =					fast.next.next, slow.next

							# 2. Push the second half into the stack
							__UpperCamelCase	:   Union[str, Any]			   =					[slow.val]
							while slow.next:
														__UpperCamelCase	:   str			   =					slow.next
														stack.append(slow.val)

							# 3. Comparison
							while stack:
														if stack.pop() != cur.val:
																					return False
														__UpperCamelCase	:   Union[str, Any]			   =					cur.next

							return True




def 	_SCREAMING_SNAKE_CASE					(		_lowerCamelCase :			Dict)					->    Tuple:






							'''simple docstring'''





							if not head or not head.next:
														return True
							__UpperCamelCase	:   Tuple			   =					{}
							__UpperCamelCase	:   int			   =					0
							while head:
														if head.val in d:
																					d[head.val].append(_lowerCamelCase)
														else:
																					__UpperCamelCase	:   int			   =					[pos]
														__UpperCamelCase	:   Tuple			   =					head.next
														pos += 1
							__UpperCamelCase	:   Union[str, Any]			   =					pos - 1
							__UpperCamelCase	:   Any			   =					0
							for v in d.values():
														if len(_lowerCamelCase) % 2 != 0:
																					middle += 1
														else:
																					__UpperCamelCase	:   List[str]			   =					0
																					for i in range(0						,  len(_lowerCamelCase)):
																												if v[i] + v[len(_lowerCamelCase) - 1 - step] != checksum:
																																			return False
																												step += 1
														if middle > 1:
																					return False
							return True

from __future__ import annotations

import sys
from collections import deque
from typing import Generic, TypeVar

lowercase  :					Optional[Any]													=       TypeVar('T')




class  lowerCamelCase__							(				Generic[T]):




	'''simple docstring'''




	_A								=     42  # Cache store of keys
	_A								=     42  # References of the keys in cache
	_A								=     1_0  # Maximum capacity of cache







	def __init__(					self		:Optional[Any]     ,   a		:int						)		-> None:
								__UpperCamelCase	:   Union[str, Any]			   =					deque()
								__UpperCamelCase	:   str			   =					set()
								if not n:
															__UpperCamelCase	:   Union[str, Any]			   =					sys.maxsize
								elif n < 0:
															raise ValueError("n should be an integer greater than 0."						)
								else:
															__UpperCamelCase	:   Any			   =					n







	def    _lowerCamelCase				(					self		:Tuple     ,   a		:T						)		-> None:
								if x not in self.key_reference:
															if len(self.dq_store						) == LRUCache._MAX_CAPACITY:
																						__UpperCamelCase	:   int			   =					self.dq_store.pop()
																						self.key_reference.remove(a						)
								else:
															self.dq_store.remove(a						)

								self.dq_store.appendleft(a						)
								self.key_reference.add(a						)







	def    _lowerCamelCase				(					self		:Any						)		-> None:
								for k in self.dq_store:
															print(a						)







	def __repr__(					self		:Tuple						)		-> str:
								return f'LRUCache({self._MAX_CAPACITY}) => {list(self.dq_store						)}'


if __name__ == "__main__":
		import doctest

		doctest.testmod()

		lowercase  :					LRUCache[str | int]													=       LRUCache(4)
		lru_cache.refer('A')
		lru_cache.refer(2)
		lru_cache.refer(3)
		lru_cache.refer('A')
		lru_cache.refer(4)
		lru_cache.refer(5)
		lru_cache.display()

		print(lru_cache)
		assert str(lru_cache) == "LRUCache(4) => [5, 4, 'A', 3]"