#include <iostream>
using namespace std;
#define MAX 100
class Deque {
int arr[MAX];
int front;
int rear;
int size;
public:
Deque(int size)
{
front = -1;
rear = 0;
this->size = size;
}
void insertrear(int key);
void deletefront();
void deleterear();
bool isFull();
bool isEmpty();
int getFront();
int getRear();
};
bool Deque::isFull()
{
return ((front == 0 && rear == size - 1)
|| front == rear + 1);
}
bool Deque::isEmpty() { return (front == -1); }
void Deque::insertrear(int key)
{
if (isFull()) {
cout << " Overflow\n " << endl;
return;
}
if (front == -1) {
front = 0;
rear = 0;
}
else if (rear == size - 1)
rear = 0;
else
rear = rear + 1;
arr[rear] = key;
}
void Deque::deletefront()
{
if (isEmpty()) {
cout << "Queue Underflow\n"
<< endl;
return;
}
if (front == rear) {
front = -1;
rear = -1;
}
else
if (front == size - 1)
front = 0;
else
front = front + 1;
}
void Deque::deleterear()
{
if (isEmpty()) {
cout << " Underflow\n"
<< endl;
return;
}
if (front == rear) {
front = -1;
rear = -1;
}
else if (rear == 0)
rear = size - 1;
else
rear = rear - 1;
}
int Deque::getFront()
{
if (isEmpty()) {
cout << " Underflow\n"
<< endl;
return -1;
}
return arr[front];
}
int Deque::getRear()
{
if (isEmpty() || rear < 0) {
cout << " Underflow\n"
<< endl;
return -1;
}
return arr[rear];
}
int main()
{
Deque dq(5);
cout << "Insert element at rear end : 5 \n";
dq.insertrear(5);
cout << "insert element at rear end : 10 \n";
dq.insertrear(10);
cout << "insert element at rear end : 15 \n";
dq.insertrear(15);
cout << "Get rear element : "
<< " " << dq.getRear() << endl;
dq.deleterear();
cout << "After delete rear element new rear"
<< " become : " << dq.getRear() << endl;
cout << "Get front element : " << dq.getFront() << endl;
dq.deletefront();
cout << "After delete front element new "
<< "front become : " << dq.getFront() << endl;
return 0;
}