package DataStructures.Easy.Sets;

import java.util.HashSet;
import java.util.Iterator;

public class Sets {

    public static void main(String[] args) {

        HashSet<String> fullList = new HashSet<String>();
        fullList.add("person1@gmail.com");
        fullList.add("person2@gmail.com");
        fullList.add("person3@gmail.com");
        fullList.add("person4@gmail.com");
        fullList.add("person5@gmail.com");

        HashSet<String> sentList = new HashSet<String>();
        sentList.add("person2@gmail.com");
        sentList.add("person3@gmail.com");

        HashSet<String> remainingList = new HashSet<String>();

        Iterator<String> iter = fullList.iterator();

        while (iter.hasNext()) {
            String nextEmail = iter.next();
            if (!Contains(sentList, nextEmail)) {
                remainingList.add(nextEmail);
            }
        }

        System.out.println("Send emails to the following: ");
        iter = remainingList.iterator();
        while (iter.hasNext()) {
            System.out.println(iter.next());
        }

    }

    private static boolean Contains(HashSet<String> sentList, String str) {
        return sentList.contains(str);
    }

}