



'''simple docstring'''





import random



def __lowerCAmelCase (     SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  ):
			lowercase__  ,       lowercase__  ,       lowercase__					  =				[], [], []
			for element in data:
						if element < pivot:
									less.append(lowerCAmelCase__  )
						elif element > pivot:
									greater.append(lowerCAmelCase__  )
						else:
									equal.append(lowerCAmelCase__  )
			return less, equal, greater




def __lowerCAmelCase (     SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  ):
			# index = len(items) // 2 when trying to find the median
			#   (value of index when items is sorted)

			# invalid input
			if index >= len(lowerCAmelCase__  ) or index < 0:
						return None

			lowercase__					  =				items[random.randint(0						,  len(lowerCAmelCase__  ) - 1  )]
			lowercase__					  =				0
			lowercase__  ,       lowercase__  ,       lowercase__					  =				_partition(lowerCAmelCase__						,  lowerCAmelCase__  )
			lowercase__					  =				len(lowerCAmelCase__  )
			lowercase__					  =				len(lowerCAmelCase__  )

			# index is the pivot
			if m <= index < m + count:
						return pivot
			# must be in smaller
			elif m > index:
						return quick_select(lowerCAmelCase__						,  lowerCAmelCase__  )
			# must be in larger
			else:
						return quick_select(lowerCAmelCase__						,  index - (m + count)  )









def __lowerCAmelCase (     SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  ):
			lowercase__  ,       lowercase__					  =				len(SCREAMING_SNAKE_CASE_  ), len(grid[0]  )
			if (
			    min(SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  ) < 0
			    or row == row_length
			    or col == col_length
			    or (row, col) in visit
			    or grid[row][col] == 1
			):
						return 0
			if row == row_length - 1 and col == col_length - 1:
						return 1

			visit.add((row, col)  )

			lowercase__					  =				0
			count += depth_first_search(SCREAMING_SNAKE_CASE_						,  row + 1						,  SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  )
			count += depth_first_search(SCREAMING_SNAKE_CASE_						,  row - 1						,  SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_  )
			count += depth_first_search(SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_						,  col + 1						,  SCREAMING_SNAKE_CASE_  )
			count += depth_first_search(SCREAMING_SNAKE_CASE_						,  SCREAMING_SNAKE_CASE_						,  col - 1						,  SCREAMING_SNAKE_CASE_  )

			visit.remove((row, col)  )
			return count


if __name__ == "__main__":
							import doctest

							doctest.testmod()




