code: def describe_list_indices(full_list):
      
      unique_elements = []
      element_indices = {}
  
      for i in range(len(full_list)):
          item = full_list[i]
          # new item
          if item not in unique_elements:
              unique_elements.append(item)
              element_indices[item] = [i]
          # previously seen item
          else:
              element_indices[item].append(i)
      return unique_elements, element_indices
docs: Parameters
      ----------
      full_list : list
          The list of items to order and
  
      Returns
      -------
      unique_elements : list
          A list of the unique elements of the list, in the order in which
          they first appear.
      element_indices : dict
          A dictionary of lists for each unique element, giving all the
          indices in which they appear in the original list.