C++ program to perform all basic operations on queue

Program to perform all basic operations on queue

#include<iostream.h>
#include<conio.h>
#include<process.h>
class stud //CLASS DECLARATION
  {
char name[20];
stud *rear,*front;
public:
void add_end();
void add_front();
void del_front();
void del_end();
void display();
stud *link;
stud()
{
front = NULL;
rear=NULL;      //CONSTRUCTOR
}
};


//FUNCTION TO ADD IN THE END OF QUEUE
void stud::add_end()
  {
stud *temp;
if(rear==NULL)
{
rear=new stud;
cout<<"\n\tEnter the name ";
cin>>rear->name;
rear->link=NULL;
front=rear;
}
  else
    {
    temp=new stud;
    cout<<"\n\tEnter the name ";
    cin>>temp->name;
    temp->link=NULL;
    rear->link=temp;
    rear=temp;
    }
  }
//FUNCTION TO ADD IN THE FRONT OF THE QUEUE
void stud::add_front()
  {
  stud *temp;
  if(front==NULL)
{
front=new stud;
cout<<"\n\tEnter the name ";
cin>>front->name;
front->link=NULL;
rear = front;
}
  else
{
temp=new stud;
cout<<"\n\tEnter the name ";
cin>>temp->name;
temp->link=NULL;
temp->link=front;
front = temp;
}
  }
//FUNCTION TO DELETE FROM THE FRONT OF THE  QUEUE
void stud::del_front()
  {
  stud *temp;
  if(front==NULL)
    cout<<"\n\t\Queue is empty \";
  else
    {
    temp=new stud;
    temp=front;
front=front->link;


temp->link=NULL;
delete(temp);
}
  }
//FUNCTION TO DELETE FROM THE END OF THE QUEUE
void stud::del_end()
  {
  stud *temp,*back;
  if(rear==NULL)
cout <<"\n\t\Queue is empty \n";
  else
{
temp = front;
while (temp->link != NULL)
{
back = temp;
temp = temp->link;
}
back->link = NULL;
rear = back;
delete(temp);
}
  }
//FUNCTION TO DISPLAY THE QUEUE
void stud::display()
  {
  stud *temp;
  clrscr();
  if(front==NULL)
cout<<"\n\t\Queue is empty \n";
  else
    {
    cout<<"\n\n\t\t THE NAMES ARE ";
    temp=new stud;
temp=front;
    while(temp->link!=NULL)
      {
      cout<<"\n\t"<<temp->name;   //DISPLAYS THE NODE DATA
      temp=temp->link;       //TO POINT TO NEXT NODE
  }
    cout<<“\n\t”<<temp->name;
    }
  }
//M A I N   P R O G R A M
void main()
  {
  stud x;
  int ch;
  char choi='y';
  while((choi=='y')||(choi=='Y'))
    {
    clrscr();
cout << "\n\n\n\t\t\t——MENU——\n";    //TO SHOW MENU
cout << "\n\t\t\t 1. Add in the front. ";
cout << "\n\t\t\t 2. Add in the last";
cout << "\n\t\t\t 3. Delete from the front";
cout << "\n\t\t\t 4. Delete from the end. ";
cout << "\n\t\t\t 5.Exit ";
cout << "\n\n\n\n\n\tEnter your choice ";
cin>>ch;
switch(ch) //STATEMENT TO REACH THE REQUIRED INSERTION
  {
  case 1:    
x.add_front();
  break;
  case 2 :    
x.add_end();
  break;
case 3 :
x.del_front();
break;
  case 4 :  
x.del_end();
break;
case 5 :  
exit(0);
  break;
  default:
  cout<<"\n\tInvalid choice ";
  }
x.display();
cout<<"\n\n\tPress y to continue.... ";
cin>>choi;
}
  }  // E N D   O F   M A I N




Step by step explanation of programme:

1. #include<iostream.h>, #include<conio.h>, #include<process.h> are the header files.
2. 'class stud' is a class declaration.
3.  'void add_end();, void add_front();,void del_front();, void del_end();, void display();, stud *link;' are all the public function i.e we can use at anywhere.
4. Use the function of 'add,delete from front of the queqe and add, delete from end of the queqe' and dislay the queqe.
5. Now use the main function for print all operation.