#include <iostream>
using namespace std;
class node // node class declaration 
{
public:
 int age;
 node *next;
};
class Priority_Queue // priority queue class declaration
{
private:
 node *f;
public:
 Priority_Queue()
 {
 f = NULL;
 }
 void insert(int p) // insert nodes in decreasing order
 {
 node *t, *q;
 t = new node;
 t->age = p;
 if (f == NULL || p > f->age)
 {
 t->next = f;
 f = t;
 }
 else
 {
 q = f; 
 while (q->next != NULL && q->next->age >= p)
 q = q->next;
 t->next = q->next;
 q->next = t;
 }
 }
 void delet()
 {
 node *t;
 if (f == NULL) // if queue is null
 cout << "Queue Underflow\n";
 else
 {
 t = f;
 cout << "Deleted item is: " << t->age << endl;
 f = f->next;
 delete(t);
 }
 }
 void show() //print queue
 {
 node *ptr;
 ptr = f;
 if (f == NULL)
 cout << "Queue is empty\n";
 else
 {
 cout << "Queue is :\n";
 cout << "Priority Item\n";
 while (ptr != NULL) 
 {
 cout << ptr->age << endl;
 ptr = ptr->next;
 }
 }
 }
};
int main()
{

 int c, p;
  Priority_Queue pq;
  	cout<<"\n\n****************************************"<<"\n\n";
	cout<<"AL-JUNAID INSTITIUTE OF GROUP"<<"\n\n";
	cout<<"For Paid Contact on me= 0304-1659294"<<"\n\n";
	cout<<"Must Change Variables"<<"\n\n";
	cout<<"****************************************"<<"\n\n";
 cout << "\nWelcome to Patient information system" <<"\n\n";
 
 do
 {
 cout << "-----------------------" <<"\n";
 cout << " Main Menu" << endl;
 cout << "-----------------------" <<"\n";
 cout << "1.Insert\n";
 cout << "2.Delete\n";
 cout << "3.Display\n";
 cout << "4.Exit\n";
 cout << "Enter your choice : ";
 cin >> c;
 switch (c)
 {
 case 1:
 cout << "Input the item value to be added in the queue : ";
 cin >> p;
 pq.insert(p);
 break; 
 case 2:
 pq.delet();
 break;
 case 3:
 pq.show();
 break;
 case 4:
 break;
 default:
 cout << "Wrong choice\n";
 }
 } while (c != 4);
 cout << endl;
 return 0;
}