Queue is a linear data structure in which insertion and deletion of elements takes place from two opposite ends rear and front respectively.
#include<iostream.h>
#include<conio.h>
struct node
{
int data;
node *next;
};
class queue
{
node *rear,*front;
public:
queue()
{ rear=NULL;front=NULL;}
void qinsert();
void qdelete();
void qdisplay();
~queue();
};
void queue::qinsert()
{
node *temp;
temp=new node;
cout<<"Data :";
cin>>temp->data;
temp->next=NULL;
if(rear==NULL)
{
rear=temp;
front=temp;
}
else
{
rear->next=temp;
rear=temp;
}
}
void queue::qdelete()
{
if(front!=NULL)
{
node *temp=front;
cout<<front->data<<"deleted \n";
front=front->next;
delete temp;
if(front==NULL)
rear=NULL;
}
else
cout<<"Queue Empty..";
}
void queue::qdisplay()
{
node *temp=front;
while(temp!=NULL)
{
cout<<temp->data<<endl;
temp=temp->next;
}
}
queue::~queue()
{
while(front!=NULL)
{
node *temp=front;
front=front->next;
delete temp;
}
}
void main()
{
queue obj; char ch;
do
{
cout<< "i. insert\nd. Delete\ns. Display\n q. quit ";
cin>>ch;
switch(ch)
{
case 'i' : obj.qinsert();break;
case 'd' : obj.qdelete();break;
case 's' : obj.qdisplay();
}
}while(ch!='q');
}