//**************************************
// Name: A simple demostraion of Sets and sets operations by using a Class
// Description:I have demonstrated a nice use of set data structure represented by a Class.
Here is the assignment.
You have to Create a class IntegerSet for which each object can hold integers in the range 0 through 100. A set is represented internally as an array of ones and zeros. Array element a[i] is 1 if integer i is in the set. Array element a[j] is 0 if integer j is not in the set. The default constructor initializes a set to the so-called “empty set,” i.e., a set whose array representation contains all zeros. 
Provide member functions for the common set operations. For example, provide a unionOfSets member function that creates a third set that is the set-theoretic union of two existing sets (i.e., an element of the third set’s array is set to 1 if that element is 1 in either or both of the existing sets, and an element of the third set’s array is set to 0 if that element is 0 in each of the existing sets).
Provide an intersectionOfSets member function which creates a third set which is the set-theoretic intersection of two existing sets (i.e., an element of the third set’s array is set to 0 if that element is 0 in either or both of the existing sets, and an element of the third set’s array is set to 1 if that element is 1 in each of the existing sets).
Provide an insertElement member function that inserts a new integer k into a set (by setting a[k] to 1). Provide a deleteElement member function that deletes integer m (by setting a[m] to 0). 
Provide a printSet member function that prints a set as a list of numbers separated by spaces. Print only those elements that are present in the set (i.e., their position in the array has a value of 1). Print --- for an empty set.
Provide an isEqualTo member function that determines whether two sets are equal.
Provide an additional constructor that receives an array of integers and the size of that array and uses the array to initialize a set object.
Now write a driver program to test your IntegerSet class. Instantiate several IntegerSet objects. Test that all your member functions work properly. 

// By: Aba
//
//This code is copyrighted and has// limited warranties.Please see http://www.PlanetSourceCode.com/vb/scripts/ShowCode.asp?txtCodeId=8835&lngWId=3//for details.//**************************************

#include<iostream.h>
const SIZE=101;//0 to 100 set containing 101 elements
class IntegerSet
{
		int a[SIZE];
	public:
		IntegerSet();
		IntegerSet(int *, int);
		IntegerSet unionOfSets(IntegerSet s2);
		IntegerSet intersectionOfSets(IntegerSet s2);
		int isEqualTo(IntegerSet s2);
		void insertElement(int n);
		void printSet();
};
IntegerSet::IntegerSet()//default constructor creates empty set
{
	int i;
	for(i=0;i<SIZE;i++)
		a[i]=0;
}
IntegerSet::IntegerSet(int *ptr, int n)//initialize object using another array of integers
{
	int i;
	for(i=0;i<SIZE;i++)//Initialize the set first
		a[i]=0;
	for(i=0;i<n;i++)
		a[(ptr[i])]=1;
}
IntegerSet IntegerSet::unionOfSets(IntegerSet s2)
{
	 IntegerSet s3;
	 int i;
	 for(i=0;i<SIZE;i++)
		if(a[i]==1 || s2.a[i]==1)
			s3.a[i]=1;
	 return s3;
}
IntegerSet IntegerSet::intersectionOfSets(IntegerSet s2)
{
	 IntegerSet s3;
	 int i;
	 for(i=0;i<SIZE;i++)
		if(a[i]==1 && s2.a[i]==1)
			s3.a[i]=1;
	 return s3;
}
int IntegerSet::isEqualTo(IntegerSet s2)
{
	int i;
	int check=1;//equal
	for(i=0;i<SIZE;i++)
	 if(a[i]!=s2.a[i])
	 {
		check=0;//not equal
		break;
	 }
	return check;
}
void IntegerSet::insertElement(int n)
{
	if (n<SIZE && n>=0) //check validity
		a[n]=1;
}
void IntegerSet::printSet()
{
	int i, count=0;
	for(i=0;i<SIZE;i++)
		if(a[i]==1)
		{
			count++;
			cout<<i<<" ";
		}
	if(count==0)
		cout<<"---";
}
void main()
{
	int arr[4]={3,76,34,56};
	IntegerSet s1, s2(arr, 4), s3, s4;
	s4.insertElement(34);
	s4.insertElement(56);
	cout<<"\nDefault set=";
	s1.printSet();
	cout<<"\nUsing array as parameter, set s2= ";
	s2.printSet();
	cout<<endl;
	cout<<"Inserting 50, 100,1,0,34, 56 to s1, set s1=";
	s1.insertElement(50);
	s1.insertElement(100);
	s1.insertElement(1);
	s1.insertElement(0);
	s1.insertElement(34);
	s1.insertElement(56);
	s1.printSet();
	cout<<endl;
	cout<<"Union of s1 and s2, set s3=";
	s3=s1.unionOfSets(s2);
	s3.printSet();
	cout<<endl;
	cout<<"Intersection of s1 and s2, set s3=";
	s3=s1.intersectionOfSets(s2);
	s3.printSet();
	cout<<endl;
	cout<<"set s4=";
	s4.printSet();
	cout<<endl;
	cout<<"s2==s3=";
	if(s2.isEqualTo(s3)==1)
		cout<<"True";
	else
		cout<<"False";
	cout<<"\ns3==s4=";
	if(s3.isEqualTo(s4)==1)
		cout<<"True";
	else
		cout<<"False";
}