#include <iostream>
using namespace std;

class Queue
{
	private:
		struct Node
		{
			Node (int data, Node* next) :
				mydata(data), mynext(next) {}
			int mydata;
			Node *mynext;
		};
	public:
		Queue() : myfront(NULL), myback(NULL) {}
		~Queue();
		int front() const;
		int back() const;
		bool is_empty() const;
		void enqueue(const int);
		void dequeue();
		void Filter(int);
		void callFilter(); //Calles the filter function
		private:
		Node* myfront;
		Node* myback;
	};
/* Implementation of member functions */
Queue :: ~Queue()
{
	if (myfront == NULL) return;
	for (Node *p = myfront->mynext; p; p=p->mynext)
		delete myfront;
}

int Queue :: front() const
{
    return myfront->mydata;
}

int Queue :: back () const
{
    return myback->mydata;
}

bool Queue :: is_empty () const
{
     return bool(myfront == NULL);
}

void Queue::callFilter()
{
     int value, count;
     count = 0;
     cout << "Please enter the value that you wish to search for(anything other than 0: ";
     cin >> value;
     while (count < 10)
		if (value > 0) {
			Filter(value);
			break;
		}
		else { 
			cout << "Please enter a new value you have " << 10-count << " chances left: ";
			cin >> value;
			count++;
		}
}	
void Queue::Filter(int A) {
  int B, C, count;
  Node *p=myback;
  B=front();
  C=B; // to remeber the first value
  // cout<<B<<endl;
  // cout<<C<<endl;
  cout << A << endl;
  
  while(A != front()) {
	p=p->mynext;
	int d=myfront->mydata;
	delete myfront;
	myfront=p;//the dequeue

	if (front()==A)
		break;
	
	Node *p=new Node(B, NULL);//the enqueue
	
	if (myback == NULL){
		myback=p;
		myfront=p;
	}
	else {
		p->mynext=myback;
		myback=p;
	}
	
	B=front();
	
	if(front()==C)	  
	  break;
	
	dequeue();
               
	}
	
	while(front()!=C)
	{               
		p=p->mynext;
		B=myfront->mydata;
		delete myfront;
		myfront=p;
		enqueue(B);  
		B=front();					 
	}
}
void Queue :: enqueue(const int d)
{
     Node *p=new Node(d, NULL);
     if (myback == NULL){
		myback=p;
		myfront=p;
	}
	else {
		p->mynext=myback;
		myback=p;
	}
	
	cout<<"Item entered into the queue: "
		<<myback->mydata<<endl;
}

void Queue :: dequeue()
{
	Node *p=myback;
	if (is_empty())
		cout << "Queue empty: Nothing to delete"<<endl;
	else {
		if (myback==myfront){
			cout<<"Item removed from queue: "
				<<myback->mydata<<endl;
			delete myback;
			myback=NULL;
			myfront=NULL;
		}
		while(p->mynext != myfront)
			p=p->mynext;
		
		int d=myfront->mydata;
		
		cout << "Item removed from queue: " << d << endl;
		delete myfront;
		myfront=p;
	}
}

main() /* A test-drive for queue */
{
       Queue q;
       q.enqueue(45);
       q.enqueue(56);
       q.enqueue(32);
      
        q.enqueue(89);
        q.enqueue(12);
      
       q.callFilter();
       q.dequeue();
       q.dequeue();
       q.dequeue();
       q.dequeue();
       q.dequeue();
}