توضيح كود Round Robin

#include <iostream>
using namespace std;

class nod
{public:
int data;
nod *next;
nod *prev;


nod(int x)
{
next= NULL;
prev= NULL;
data=x;

}
};


class queu{
public:
nod *h;

queu()

{h=NULL;}


bool empty()
{
if (h->next == h->prev)
return 1;
else
return 0;
}


void enqueu (int num)
{
int x;

nod *temp;
temp = new nod(x);
temp ->data = num;
if (h == NULL){
h =temp;
h ->next =h;
h->prev =h;}
else{
h->prev->next=h;
temp->prev=h->prev;
h->prev=temp;
temp->next=h;}
}

int Dequeue()
{ int temp;
temp= h->data;
if( h== h->prev )
{
delete h;
h=NULL;}

else {
nod *h2;
h2=h->next;
h->next->prev=h->prev;
h->prev->next=h->next;
h->next=NULL;
h->prev=NULL;
delete h;
h=h2;

}return temp;
}

void print()
{
nod *p=h;
while (p!=NULL)
{
cout<<p->data;
p=p->next;}
}
};







void main()
{
int x;
queu obj;
int choice,time_slice ,cpu_time;

cin>>x;

cout<<"1.enter 1 to insert cpu time\n 2.enter 2 to insert the time slice . \n 3- enter 3 to perform RR algorethem ";

cin>>choice;


while (choice>0){

switch (choice)

{

case 1:
cin>>cpu_time;break;

case 2:
cin>>time_slice;break;

case 3:
while(!obj.empty());
{
x= obj.Dequeue();
x=x - time_slice;
if(x>0)
obj.enqueu(x);
obj.print();
}
break;

default :
cout<<"try again";

}

cin>>choice;
}
}