В чем собственно погрешность?
package com.javarush.task.task14.task1415;
import java.util.ArrayList;
import java.util.List;
/*
Клининговый центр
*/
public class Solution {
public static void main(String[] args) {
List<Apartment> apartments = new ArrayList<Apartment>();
apartments.add(new OneRoomApt());
apartments.add(new TwoRoomApt());
apartments.add(new ThreeRoomApt());
cleanAllApartments(apartments);
}
public static void cleanAllApartments(List<Apartment> apartments) {
//написать тут вашу реализацию пунктов 1-4
for (int i=0;i<apartments.size();i++){
if (apartments.get(i) instanceof OneRoomApt){
Apartment apartment = new OneRoomApt();
((OneRoomApt) apartment).clean1Room();
}else if (apartments.get(i) instanceof TwoRoomApt){
Apartment apartment = new TwoRoomApt();
((TwoRoomApt) apartment).clean2Rooms();
}else if(apartments.get(i) instanceof ThreeRoomApt){
Apartment apartment = new ThreeRoomApt();
((ThreeRoomApt) apartment).clean3Rooms();
}
}
}
static interface Apartment {
}
static class OneRoomApt implements Apartment {
void clean1Room() {
System.out.println("1 room is cleaned");
}
}
static class TwoRoomApt implements Apartment {
void clean2Rooms() {
System.out.println("2 rooms are cleaned");
}
}
static class ThreeRoomApt implements Apartment {
void clean3Rooms() {
System.out.println("3 rooms are cleaned");
}
}
}