Реализация алгоритма MROC3. Статья "MROC3 - не магия, а справедливое слияние очередей" находится по ссылке https://drive.google.com/file/d/1MeunpCBtUdlfEtXxLqAcidjloVCPHtoJ/view?usp=sharing

MROC3.py

Cls_parents, Calc_linear = {}, {}

def not_in_tail(elem, queue):
    return elem == queue[0] or elem not in queue #или в начале очереди, или не стоит в ней

def create_queues(parents):
    if not parents: return []
    queues = []
    for parent in parents:
        new_queue = Calc_linear[parent].copy()
        queues.append(new_queue)
    queues.append(parents)
    return queues


def delete_from_queues(cls_to_del, queues):
    for q in queues:
        if q and q[0] == cls_to_del:
            del q[0]
    return list(filter(len, queues))


def merge(parents):
    queues = create_queues(parents)
    precedence_order = []
    while queues:
        for queue in queues:
            next_class = queue[0]
            if all(not_in_tail(next_class, q) for q in queues):
                precedence_order.append(next_class)
                queues = delete_from_queues(next_class, queues)
                break
        else:
            raise TypeError  # нельзя построить линеаризацию
    return precedence_order

def linearize(new_class, parents):
    return [new_class, *merge(parents)]
  

MROC3_counter.py

from collections import Counter

Cls_parents, Calc_linear = {}, {}

def create_queues(parents):
    if not parents: return []
    queues = []
    for parent in parents:
        new_queue = Calc_linear[parent].copy()
        queues.append(new_queue)
    queues.append(parents)
    return queues

def create_tail_stat(queues):
    tail_statistics = Counter()
    for queue in queues:
        new_stat = Counter(queue)
        new_stat[queue[0]] -= 1 # статистика, сколько раз класс в хвосте
        tail_statistics += new_stat
    return tail_statistics


def delete(cls_to_del, queues, tail):
    for q in queues:
        if q and q[0] == cls_to_del:
            del q[0]
            if q:
                tail[q[0]] -= 1 # следующий класс стал головой списка
    return list(filter(len, queues))


def merge(parents):
    queues = create_queues(parents)
    tail_statistics = create_tail_stat(queues)
    precedence_order = []
    while queues:
        for queue in queues:
            next_class = queue[0]
            if tail_statistics[next_class] == 0: # нет в хвосте
                precedence_order.append(next_class)
                queues = delete(next_class, queues, tail_statistics)
                break
        else:
            raise TypeError  # нельзя построить линеаризацию
    return precedence_order

def linearize(new_class, parents):
    return [new_class, *merge(parents)]