//Use LinkedLists to implement a class Set_YI.java with the following methods:
//
//        1. add(E e)
//
//        2. addAll(Collection c)
//
//        3. void clear()
//
//        4. boolean contains(Object o)
//
//        5.boolean containsAll(Collection c)
//
//        6. boolean equals(Object o)
//
//        7. boolean isEmpty()
//
//        8. Iterator iterator()
//
//        9. boolean remove(Object o)
//
//        10. boolean removeAll(Collection c)
//
//        11. int size()

// Will Morrison

import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;

public class Set_YI<E> {

    public LinkedList<E> list;

    public int size() {
        // Returns the number of elements
        return list.size();

    }

    public boolean add(E o) {
        // Ensures that this collection contains the specified element
        if (list.contains(o) == false) {
            list.add(o);
            return true;
        }
        return false;
    }


    public boolean addAll(Collection<E> c) {
        // 	Adds all of the elements in the specified collection to this set if they’re not already present
        if (list.containsAll(c) == false) {
            list.addAll(c);
            return true;
        }
        return false;
    }


    public void clear() {
        // 	Removes all of the elements from this set
        list.clear();
    }


    public boolean contains(Object o) {
        // 	Returns true if this set contains the specified element
        if (list.contains(o)) {
            return true;
        } else {
            return false;
        }
    }

    public boolean containsAll(Collection<E> c) {
        // 	Returns true if this set contains all of the elements
        if (list.containsAll(c)) {
            return true;
        } else {
            return false;
        }

    }


    public boolean equals(Object o) {
        // 	Compares the specified object with this set for equality
        if (list.equals(o)) {
            return true;
        } else {
            return false;
        }

    }

    public boolean isEmpty() {
        // 	Returns true if this set contains no elements
        if (list.isEmpty()) {
            return true;
        } else {
            return false;
        }
    }


    public Iterator<E> iterator() {
        // 	Returns an iterator over the elements in this set
        return list.iterator();

    }

    public boolean remove(Object o) {
        // 	Removes the specified element from this set if it is present
        if (list.contains(o) == true) {
            list.remove(o);
            return true;
        } else {
            return false;
        }
    }


    public boolean removeAll(Collection<E> c) {
        // Removes from this set all of its elements that are contained in the specified collection
        if (list.containsAll(c) == true) {
            list.removeAll(c);
            return true;
        } else {
            return false;
        }

    }

}