#include<iostream.h>
#include<conio.h>

typedef int itemType;

struct node{
itemType item;
node* next;
};

typedef struct node* ptrType;

class Queue{
private:
ptrType rear;
public :
Queue();
Queue(const Queue&q);
ptrType getFrontPtr();
int add(itemType);
int delet();
int getFront(itemType &);
int isEmpty();
int isFull(ptrType);
void show();
};
//-----------------------------------------------------
Queue::Queue(){rear=NULL;}
//---------------------------------------------------
Queue::Queue(const Queue &q)
{
ptrType temp=q.getFrontPtr();
do{
add(temp->item);
temp=temp->next;
}
while(temp!=q.getFrontPtr());
}
//------------------------------------------------
ptrType Queue::getFrontPtr(){ return rear->next;}
//------------------------------------------------
int Queue::isEmpty(){return rear==NULL;}
//------------------------------------------------
int Queue::isFull(ptrType temp){return (temp==NULL);}
//----------------------------------------------
int Queue:: add(itemType newItem){
ptrType temp= new node;

if(isFull(temp))
{
cout<<"\n Full Queue";
return 0;
}
else
{
if(isEmpty())
{
temp->next=temp;
}
else
{
temp->next=rear->next;
rear->next=temp;
}
temp->item=newItem;
rear=temp;
return 1;
}
}
//-------------------------------------------------
int Queue::delet(){
if(isEmpty())
{
cout<<"\n Empty Queue";
return 0;
}
else
{
ptrType front =rear->next;

if(front==rear) //one node
rear=NULL;
else
rear->next=front->next;

delete front;
return 1;
}
}
//--------------------------------------------
int Queue::getFront(itemType &item)
{
if(isEmpty())
{
cout<<"\n Empty Queue";
return 0;
}
else
{
item=rear->next->item;
return 1;
}
}
//-------------------------------------------
void Queue::show(){
if(isEmpty())
{
cout<<"\n Empty Queue";
return ;
}
else
{
ptrType temp=rear->next;

do{
cout<<temp->item<<"-";
temp=temp->next;
}while(temp!=rear->next);
}
}
//---------------------------------------------
void main(){
class Queue store,cashier;
int time=0,start,duration,entry,shop,service,
shopCount=0,cashierCount=0,max=0,x;
cout<<"\n All timings entered should be in minutes \n ";
cout<<"\n Enter the simulation time : ";
cin>>duration;
cout<<"\n Enter the customer entry intervals : ";
cin>>entry;
cout<<"\n Enter the customers shoppig time : ";
cin>>shop;
cout<<"\n The cashier service time :";
cin>>service;

do{
++time;

cout<<"\n The time in minutes"<<time;
// (1) time has come to accept new customer
if(time%entry==0)
{
store.add(time);
++shopCount;
cout<<"\n A customer started shopping- current shoppers : ";
store.show();
getch();
}
// (2) customer at the front of the shop queue has finished shopping
if(!store.isEmpty())
{
store.getFront(start);
if(time==(start+shop))
{
store.delet();
cashier.add(start);
++cashierCount;
cout<<"\n A customer finished shopping , current shoppers : ";
store.show();
cout<<"\n A customer joined the cashier queue";
cashier.show();
getch();


if( max < cashierCount)
max = cashierCount;
}
}
// (3) customer at the front of the cashierqueue has finished shopping
if(!cashier.isEmpty())
{
cashier.getFront(start);

if(time==(start+shop+service))
{
cashier.delet();
--cashierCount;
cout<<"\n A customer exited- the cashier queue changed : ";
cashier.show();
getch();
}
}
}while(time<duration);

cout<<"\n Enter the simulation time : "<< duration;
cout<<"\n Enter the customer entry intervals : "<<entry;
cout<<"\n Enter the customers shoppig time : "<<shop;
cout<<"\n The cashier service time :"<<service;
cout<<"\n Total shoppers in the given time period were"<<shopCount;
cout<<"\n The highest length of the cashier queue"<<max;

}//end main