Java で 2 つのリストを効率的に比較して、共通要素と異なる要素の両方を見つけるにはどうすればよいですか?

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);
    }
}