/**
 * Implementation of the Set ADT as a boolean array
 * 
 * @authors: Michael Edwards and Sriram Pemmaraju
 */
import java.util.*;

public class Set{

	private int n;
	private boolean[] set;
	
	/**
	 * This is the constructor for the Set.
	 *
	**/
	public Set(int size) {
		
		n = size;
		set = new boolean[n];
		for(int i = 0; i < n; i++)
			set[i] = false;
	}
	

	/**
	 * Copy constructor for duplicating a set.
	 *
	**/
	public Set(Set s)
	{
		n = s.n;
		set = new boolean[n];
		for(int i = 0; i < n; i++)
			set[i] = s.set[i];
	}

        /**
         * This is the default constructor for the Set. 
         * If no argument is provided, it will construct
         * an empty set that has the potential to hold 100 elements.
        **/
        public Set() {

		this(100);
        }


        /**
         * This inserts an element into the set. 
         *
        **/
	public void insert(int x) {
		if(x > 0 && x <= n)
			set[x-1] = true;
	}

        /**
         * This removes an element from the set. 
         *
        **/
	public void delete(int x) {
		if(x > 0 && x <= n)
			set[x-1] = false;
	}

        /**
         * Test an element for membership. 
         *
        **/
	public boolean isMember(int x) {
		if(x > 0 && x <= n)
			return set[x-1];
		else
			return false;
	}

        /**
         * Test the set to see if it is empty.
         *
        **/
	public boolean isEmpty() {
		boolean empty = true;
		for(int i = 0; i < n; i++)
			empty = empty && !set[i];

		return empty;
	}

        /**
         * Combine another set with this one using the union operation.
         *
        **/
	public void union(Set s) {
		for(int i = 0; i < n; i++)
			set[i] = set[i] || s.set[i];

	}

        /**
         * Combine another set with this one using the intersection operation.
         *
        **/
	public void intersection(Set s) {
		for(int i = 0; i < n; i++)
			set[i] = set[i] && s.set[i];
	}

	/**
	 * Return the number of elements in the set.
	 *
	**/
	public int size() {
		int size = 0;
		for(int i = 0; i < n; i++)
			if(set[i])
				size++;

		return size;
	}	

	/**
	 * Print out all the elements in this set.
	 *
	**/
	public void print() {
		System.out.print("{");
		for(int i = 0; i < n; i++)
			if(set[i])
				System.out.print((i+1)+", ");

		System.out.println("}");
	}
}