input: 
  def solve_maze(maze: Maze) -> list:
      """Solve the given maze object and return the shortest path from the start to the end.
      >>> maze = Maze(3, 3)
      >>> maze._grid = [[1, 0, 0], [1, 1, 0], [0, 1, 1]]
      >>> solve_maze(maze)
      [4]
      >>> maze._grid = [[1, 1, 1], [0, 0, 1], [0, 0, 1]]
      >>> solve_maze(maze)
      [4]
      """
  
output:     from collections import deque
  
      def bfs(start, end, grid):
          rows, cols = len(grid), len(grid[0])
          queue = deque([(start, [start])])
          visited = set()
          visited.add(start)
  
          while queue:
              (current, path) = queue.popleft()
              r, c = divmod(current, cols)
  
              if current == end:
                  return path
  
              for dr, dc in [(-1, 0), (1, 0), (0, -1), (0, 1)]:
                  nr, nc = r + dr, c + dc
                  if 0 <= nr < rows and 0 <= nc < cols and grid[nr][nc] == 1:
                      neighbor = nr * cols + nc
                      if neighbor not in visited:
                          visited.add(neighbor)
                          queue.append((neighbor, path + [neighbor]))
  
          return []
  
      start = maze.start
      end = maze.end
      grid = maze._grid
  
      return bfs(start, end, grid)