공통 요소와 다른 요소를 모두 찾기 위해 Java의 두 목록을 효율적으로 비교하려면 어떻게 해야 합니까?

import java.util.Collection;
import java.util.ArrayList;

public class ListComparison {
    public static void main(String[] args) {
        Collection<String> list1 = new ArrayList<>(Arrays.asList("milan", "dingo", "elpha", "hafil", "meat", "iga", "neeta.peeta"));
        Collection<String> list2 = new ArrayList<>(Arrays.asList("hafil", "iga", "binga", "mike", "dingo"));

        list1.retainAll(list2);
        System.out.println("Common elements: " + list1);
    }
}

import java.util.Collection;
import java.util.HashSet;

public class ListComparison2 {
    public static void main(String[] args) {
        Collection<String> list1 = Arrays.asList("milan", "iga", "dingo", "iga", "elpha", "iga", "hafil", "iga", "meat", "iga", "neeta.peeta", "iga");
        Collection<String> list2 = Arrays.asList("hafil", "iga", "binga", "mike", "dingo", "dingo", "dingo");

        Collection<String> common = new HashSet<>(list1);
        Collection<String> different = new HashSet<>();
        different.addAll(list1);
        different.addAll(list2);

        common.retainAll(list2);
        different.removeAll(common);

        System.out.printf("Common elements: %s%nDifferent elements: %s%n", common, different);
    }
}

public class CustomListComparison {
    public static void main(String[] args) {
        List<String> list1 = Arrays.asList("milan", "dingo", "elpha", "hafil", "meat", "iga", "neeta.peeta");
        List<String> list2 = Arrays.asList("hafil", "iga", "binga", "mike", "dingo");

        List<String> common = new ArrayList<>();
        List<String> different = new ArrayList<>();

        for (String element : list1) {
            if (list2.contains(element)) {
                common.add(element);
            } else {
                different.add(element);
            }
        }

        for (String element : list2) {
            if (!list1.contains(element)) {
                different.add(element);
            }
        }

        System.out.printf("Common elements: %s%nDifferent elements: %s%n", common, different);
    }
}