GROUP E
PRACTICAL NO 14
Name: Mansi Parmar
Roll no: S212065
Div: B
Batch: B3
A double-ended queue (deque) is a linear list in which additions and deletions
may be made at either end. Obtain a data representation mapping a deque into a
one-dimensional array. Write C++ program to simulate deque with functions to
add and delete elements from either end of the deque.
#include<iostream>
using namespace std;
#define SIZE 5
class dequeue{
private:
int a[10],front,rear,count;
public:
dequeue();
void add_at_beg(int);
void add_at_end(int);
void delete_fr_front();
void delete_fr_rear();
void display();
};
dequeue::dequeue(){
front=-1;
rear=-1;
count=0;
void dequeue::add_at_beg(int item){
int i;
if(front==-1){
front++;
rear++;
a[rear]=item;
count++;
else if(rear>=SIZE-1){
cout<<"\nInsertion is not possible,overflow!!!!";
else{
for(i=count;i>0;i--){
a[i]=a[i-1];
a[i]=item;
count++;
rear++;
void dequeue::add_at_end(int item){
if(front==-1){
front++;
rear++;
a[rear]=item;
count++;
}
else if(rear>=SIZE-1){
cout<<"\nInsertion is not possible,overflow!!!";
return;
else{
a[++rear]=item;
count++;
void dequeue::display(){
for(int i=front;i<=rear;i++){
cout<<a[i]<<" ";
void dequeue::delete_fr_front(){
if(front==-1){
cout<<"Deletion is not possible:: Dequeue is empty";
return;
else{
if(front==rear){
front=rear=-1;
return;
cout<<"The deleted element is "<<a[front];
front=front+1;
}
void dequeue::delete_fr_rear(){
if(front==-1){
cout<<"Deletion is not possible:Dequeue is empty";
return;
else{
if(front==rear){
front=rear=-1;
cout<<"The deleted element is "<< a[rear];
rear=rear-1;
int main(){
int c,item;
dequeue d1;
do{
cout<<"\n\n***DEQUEUE OPERATION*\n";
cout<<"\n1-Insert at beginning";
cout<<"\n2-Insert at end";
cout<<"\n3_Display";
cout<<"\n4_Deletion from front";
cout<<"\n5-Deletion from rear";
cout<<"\n6_Exit";
cout<<"\nEnter your choice<1-4>:";
cin>>c;
switch(c){
case 1:
cout<<"Enter the element to be inserted:";
cin>>item;
d1.add_at_beg(item);
break;
case 2:
cout<<"Enter the element to be inserted:";
cin>>item;
d1.add_at_end(item);
break;
case 3:
d1.display();
break;
case 4:
d1.delete_fr_front();
break;
case 5:
d1.delete_fr_rear();
break;
case 6:
exit(1);
break;
default:
cout<<"Invalid choice";
break;
}while(c!=7);
return 0;}
Output
