6.vanilla_bs

//only inserting at end function is reqd.
//OBSV CAREFULLY THE CHANGES BETWEEN Intersection and Union and Only Fn.

//1. In union:
// add A to C first and then check if element is there in B , dont insert, else insert.
// flag is reqd.

//2. In intersection
// check if common. if yes insert
//No use of flag

//3. ONly
//addfrom and checkin
// flag reqd.


//sapmle test case is univ:1 2 3 4 5 6 
//van:1 2 3
//bs:2 4 1 6

#include <iostream>
using namespace std;

class node
{
	string name;
	int prn;
	node* next;
public:
	node()
	{
		name = "";
		prn = 0;
	}
	friend class ll;
};

class ll
{
public:
	node* head;
	node* tail;
public:
	ll()
	{
		head = tail = NULL;
	}
	void insert();//without node specification
	void copy(node* nn);//with node specification
	void display();
	void uni(node* ahead, node* bhead);//union
	void intersect(node* ahead, node* bhead);//intersect
	void only(node* addfrom, node* checkin);// only van, only bs, neither-nor
};

void ll::only(node* ahead, node* bhead)
{
	int flag = 0;
	while (ahead != NULL)
	{
		flag = 0;
		node* start = bhead;

		while (start != NULL)
		{
			if (start->prn == ahead->prn)
			{
				flag++;
				break;
			}
			start = start->next;
		}

		if (flag == 0)
		{
			node* nn = new node;
			nn->name = ahead->name;
			nn->prn = ahead->prn;
			nn->next = NULL;

			copy(nn);
		}

		ahead = ahead->next;
	}
}

void ll::uni(node* ahead, node* bhead)
{
	int flag = 0;

	while (ahead != NULL)//copy everything in a in c
	{
		node* nn = new node;
		nn->name = ahead->name;
		nn->prn = ahead->prn;
		nn->next = NULL;

		copy(nn);

		ahead = ahead->next;
	}

	while (bhead != NULL)//check if any same ele in b with c. if not ,insert in c.
	{
		node* chead = head;
		flag = 0;

		while (chead != NULL)
		{
			if (chead->prn == bhead->prn)
			{
				flag++;
				break;
			}

			chead = chead->next;
		}

		if (flag == 0)
		{
			node* nn = new node;
			nn->name = bhead->name;
			nn->prn = bhead->prn;
			nn->next = NULL;
			copy(nn);
		}

		bhead = bhead->next;
	}
}

void ll::intersect(node* addfrom, node*checkin )
{
	while (addfrom != NULL)
	{
		node* start = checkin;

		while (start != NULL)
		{
			if (addfrom->prn == start->prn)
			{
				node* nn = new node;
				nn->name = start->name;
				nn->prn = start->prn;
				nn->next = NULL;

				copy(nn);

				break;
			}

			start = start->next;
		}

		addfrom = addfrom->next;
	}
}

void ll::copy(node* nn)
{
	if (head == NULL && tail == NULL)//empty
	{
		head = nn;
		tail = nn;
	}
	else//not empty
	{
		tail->next = nn;
		tail = nn;
	}
}

void ll::insert()
{
	node* nn = new node;
	cout << "Enter name:" << endl;
	cin >> nn->name;
	cout << "Enter PRN:" << endl;
	cin >> nn->prn;
	nn->next = NULL;

	if (head == NULL && tail == NULL)//empty
	{
		head = nn;
		tail = nn;
		cout << "---Inserted in empty list---" << endl;
	}
	else//not empty
	{
		tail->next = nn;
		tail = nn;
		cout << "---Insertion successfull---" << endl;
	}
}

void ll::display()
{
	node* start = head;

	if (start == NULL)
	{
		cout << "---Nothing To Display---" << endl;
	}

	while (start != NULL)
	{
		cout << "Name:" << start->name << endl;
		cout << "PRN:" << start->prn << endl;
		start = start->next;
	}
}
int main()
{
	int ch,ch2,ch3,ch4;


	cout << "Univ Set:Set of All Students" << endl;
	ll univ;

	do
	{
		cout << "Insert element" << endl;
		univ.insert();

		cout << "Enter 0 to stop" << endl;
		cin >> ch4;

	} while (ch4 != 0);

	cout << "\n\tUniversal Set" << endl;
	univ.display();


	cout << "Set A: Vanilla" << endl;
	ll a;

	do
	{
		cout << "Insert element" << endl;
		a.insert();
		
		cout << "Enter 0 to stop" << endl;
		cin >> ch;

	} while (ch != 0);

	cout << "\n\tSet A" << endl;
	a.display();

	cout << "Set B :Butterscotch" << endl;

	ll b;

	do
	{
		cout << "Insert element" << endl;
		b.insert();

		cout << "Enter 0 to stop" << endl;
		cin >> ch2;

	} while (ch2 != 0);

	cout << "\n\tSet B" << endl;
	b.display();

	do
	{
		cout << "\n\tEnter your choice" << endl;
		cout << "\n\t1.Set of students who like either vanilla or butterscotch or both " << endl;
		cout << "\n\t2. Set of students who like both vanilla and butterscotch " << endl;
		cout << "\n\t3.Set of students who like only vanilla not butterscotch " << endl;
		cout << "\n\t4. Set of students who like only butterscotch not vanilla " << endl;
		cout << "\n\t5.Number of students who like neither vanilla nor butterscotch. " << endl;
		cout << "\n\t6.Exit" << endl;
		cin >> ch3;

		switch(ch3)
		{
			case 1:
			{
				cout << "\n\tUNION" << endl;
				ll c;
				c.uni(a.head, b.head);
				c.display();
				break;
			}
			case 2:
			{
				cout << "\n\tIntersection" << endl;
				ll d;
				d.intersect(a.head, b.head);
				d.display();
				break;
			}
			case 3:
			{
				cout << "\n\tOnly Vanilla" << endl;
				ll e;
				e.only(a.head, b.head);//the one in which you wanna subtract stuff.it is first parameter
				e.display();
				break;
			}

			case 4:
			{
				cout << "\n\tOnly Butterscotch" << endl;
				ll f;
				f.only(b.head, a.head);//the one in which you wanna subtract stuff.it is first parameter
				f.display();
				break;
			}

			case 5:
			{
				cout << "\n\tNeither Vanilla nor Butterscotch" << endl;
				ll g;
				ll uni;
				uni.uni(a.head, b.head);
				g.only(univ.head, uni.head);//subtract from univ the ele in union set.
				g.display();
				break;
			}

			case 6:
			{
				cout << "Thank You!!!" << endl;
				break;
			}
			default:cout << "Invalid Choice" << endl;

		}

	} while (ch3 != 6);

	return 0;
}