code: def find_shape(bottom_lines, max_len):
      
      shape = [1] * max_len
      for i in range(max_len):
          for line in bottom_lines:
              if line[0] <= i + 1 < line[2]:
                  shape[i] = line[1]
                  break
      return shape
docs: Finds a shape of lowest horizontal lines with step=1
      :param bottom_lines:
      :param max_len:
      :return: list of levels (row values), list indexes are columns