dequeWithStackandQueueImplementation.cpp

#include <iostream>
using namespace std;

struct node {
	int data;
	node* next;
	node* back;
};

class LinkedList {
public:
	LinkedList();

	node* front, * curr, * prev, * rear;

	void printing();

	void pushFront(int);

	void rearInsertion(int);

	bool isEmpty();

	int reversePop();

	int popFront();

};


LinkedList::LinkedList()
{
	front = curr = prev = rear = nullptr;
}
int LinkedList::popFront()
{
	node* temp;
	if (front == nullptr)
	{
		throw "Linked List is Empty\n";
	}
	else {
		temp = front;
		int data = front->data;
		if (front->next != nullptr)
		{
			front = front->next;
			front->back = nullptr;
		}
		else {
			front->next = nullptr;
			front->back = nullptr;
			front = nullptr;
			
		}
		delete temp;
		return data;
	}
}
int LinkedList::reversePop()
{
	node* temp;
	if (rear == nullptr)
	{
		throw "Empty Linked List\n";
	}
	else {
		int data = rear->data;
		temp = rear;
		if (rear->back == nullptr)
		{
			rear->next = nullptr;
			rear->back = nullptr;
			rear = nullptr;
			front = rear;
		}
		else
		{
			rear = rear->back;
			rear->next = nullptr;
		}
		delete temp;
		
		return data;
	}
}

bool LinkedList::isEmpty()
{
	return (front == nullptr or rear == nullptr);
}

void LinkedList::rearInsertion(int no)
{
	if (rear == nullptr)
	{
		
		rear = new node;
		rear->data = no;
		rear->next = nullptr;
		rear->back = nullptr;
		front = prev = rear;
	}
	else {
		node* temp = new node;
		rear->next = temp;
		temp->back = rear;
		temp->next = nullptr;
		temp->data = no;
		rear = temp;
	}
}

void LinkedList::pushFront(int no)
{
	if (front == nullptr)
	{
		front = new node;
		front->data = no;

		front->back = nullptr;
		front->next = nullptr;
		curr = prev = rear = front;
	}
	else {
		node* temp = new node;
		temp->data = no;
		temp->next = front;
		temp->back = nullptr;
		front = temp;
	}
}


void LinkedList::printing()
{
	curr = front;
	while (curr)
	{
		cout << curr->data << endl;

		curr = curr->next;
	}
}

int main()
{
	LinkedList stack;
	LinkedList queue;
	int no;
	int choice;
	int subchoice;
	do {
		cout << "Type 1 for Stack \n2 For Queue\n3 to end program\n";
		cin >> choice;
		switch (choice)
		{
		case 1:
			cout << "Type 1 for push\n2 for pop\n3 for printing stack\n";
			cin >> subchoice;
			switch (subchoice)
			{
			case 1:
				cout << "What to push in stack\n";
				cin >> no;
				stack.rearInsertion(no);
				break;
			case 2:
				no = stack.reversePop();   
				cout << no << " is poped from stack\n";
				break;
			case 3:
				stack.printing();
				break;
			default:
				break;
			}
			break;
		case 2:
			cout << "Type 1 for push\n2 for pop\n3 for printing queue\n";
			cin >> subchoice;
			switch (subchoice)
			{
			case 1:
				cout << "What to push in queue\n";
				cin >> no;
				queue.rearInsertion(no);
				break;
			case 2:
				no = queue.popFront();
				cout << no << " is poped from queue\n";
				break;
			case 3:
				queue.printing();
				break;
			default:
				break;
			}
			break;
		default:
			break;
		}
	} while (choice != 3);
	
	
	
}