import bisect

original_list = [8, 4, 8, 23, 99]
sorting_criteria = lambda x: x
filtering_criteria = lambda x: x < 30

#initial creation
sorted_list = [[idx, item] for idx, item in enumerate(original_list) if filtering_criteria(item)]
sorted_list.sort(key=lambda pair: sorting_criteria(pair[1]))

#insertion
to_insert = 15
if filtering_criteria(to_insert):
    for idx, item in sorted_list:
        if sorting_criteria(item) > sorting_criteria(to_insert):
            break
    else:
        idx = len(sorted_list)
    sorted_list.insert(idx, (len(original_list), to_insert))
    original_list.append(to_insert)

#updating
index_to_update = 2
new_value = 42
if filtering_criteria(new_value):
    sorted_list[index_to_update][1] = new_value
    original_list[sorted_list[index_to_update][0]] = new_value
else:
    del sorted_list[index_to_update]

#deletion
index_to_delete = 0
index_in_original_list = sorted_list[index_to_delete][0]
del sorted_list[index_to_delete]
del original_list[index_in_original_list]
sorted_list = [[idx if idx < index_in_original_list else idx-1, item] for idx, item in sorted_list]

#displaying
print([item for idx, item in sorted_list])