// Insert/adds a new ranking to the ranking list
	tError rankingList_insert(tRankingList* list, tRanking ranking, int index) {
		// PR3 EX2

		assert(list != NULL);


		tRankingListNode* new_ranking;
		tRankingListNode* current_ranking;

		new_ranking = (tRankingListNode*) malloc(list->size * sizeof(tRankingListNode));
		current_ranking = (tRankingListNode*) malloc(list->size * sizeof(tRankingListNode));

		if (new_ranking == NULL) {
			return ERR_MEMORY_ERROR;
		}

		if (current_ranking == NULL) {
			return ERR_MEMORY_ERROR;
		}

		if ((index < 1) || (index > list->size)) {
			return ERR_INVALID_INDEX;
		}

		if (index == 1){
			new_ranking->prev = NULL;
			new_ranking->next = NULL;
			new_ranking->e = ranking;
			list->first = new_ranking;
			list->last = new_ranking;
			list->size = list->size +1;
			return OK;

		}else if (index == list->size + 1){

			new_ranking->next = NULL;
			new_ranking->prev = list->last;
			new_ranking->e = ranking;
			list->first = new_ranking;
			list->last = new_ranking;
			list->size = list->size +1;
			return OK;

		} else{
			current_ranking = list->first;
    		for (int i=1; i<index; i++) {
				current_ranking = current_ranking->next;
				new_ranking->next = current_ranking;
				new_ranking->prev = current_ranking->prev;

				if (current_ranking->prev == NULL) {
					list->first = new_ranking;
				}
				else {
					current_ranking->next = new_ranking;
					current_ranking = new_ranking;
					list->size = list->size +1;
					return OK;
				}

			}
			return ERR_INVALID_INDEX;
		}

		//return OK;

	}