Linked list class

//Name:Aakash Kamleshkumar Panchal
//Student Id:201801459
//Date:14/03/2019
//Program:Implementation of Linked List


#include <iostream>
using namespace std;

template<typename E>
struct node {
	E data;
	node<E>* nextElement;
};

template <typename E>
class List
{
	void operator = (const List&) {}
	List(const List&) {}

public:
	//constructors and destructors
	List() {}
	virtual ~List() {}

	//Return the number of elements in the List
	virtual int NumberOfElements() const = 0;

	//Return the Location of current element
	virtual int CurrentLocation() const = 0;

	//Return the data of current element
	virtual const E& getData() const = 0;

	//clear all the data from the List
	virtual void clear() = 0;

	//insert a data in the List at current location
	virtual void insert(const E& data) = 0;

	//insert a data in the end of the List
	virtual void append(const E& data) = 0;

	//delete a data at the current Location
	virtual E remove() = 0;

	//set the current Location to the start of the List
	virtual void setListLocationToStart() = 0;

	//set the current Location to the end of the List
	virtual void setListLocationToEnd() = 0;

	//set the current Location to the element on left side
	// of current element
	virtual void previousElement() = 0;

	//set the current Location to the element on left side
	// of current element
	virtual void nextElement() = 0;

	//Set current Location to a new Location
	virtual int setToNewLocation(int location) = 0;

};

template <typename E>
class linkList : public List<E>
{
public:
	node<E>*firstElement;
	node<E>*lastElement;
	node<E>*currentElement;
	int sizeofList;
	int currentLocation;

	//constructors and destructors

	linkList()
	{
		firstElement = lastElement = currentElement = new node < E >;
		firstElement = lastElement = currentElement = NULL;
		currentLocation = 0;
		sizeofList = 0;
	}
	~linkList()
	{
		while (firstElement != NULL)
		{
			currentElement = firstElement;
			firstElement = firstElement->nextElement;
			delete currentElement;
		}
	}

	int NumberOfElements() const
	{
		return sizeofList;
	}

	int CurrentLocation() const
	{
		return currentLocation;
	}

	const E& getData() const
	{
		int i{ currentLocation };
		node<E>*temp = new node<E>;
		temp = firstElement;
		while (i-- > 1)
		{
			temp = temp->nextElement;
		}
		return temp->data;
	}

	void clear()
	{
		while (firstElement != NULL)
		{
			currentElement = firstElement;
			firstElement = firstElement->nextElement;
			delete currentElement;
		}
		firstElement = currentElement = lastElement = NULL;
		sizeofList = 0;
		currentLocation = 0;
	}

	void insert(const E& data)
	{
		node<E>*p = new node<E>;
		p->data = data;
		sizeofList++;
		if (currentElement == firstElement)
		{
			if (firstElement == NULL && lastElement == NULL)
			{
				lastElement = p;
			}
			p->nextElement = firstElement;
			currentElement = p;
			firstElement = p;
			currentLocation = 1;
			return;
		}
		node<E>* tN = new node<E>;
		tN = firstElement;
		while (tN->nextElement != currentElement)
		{
			tN = tN->nextElement;
		}
		tN->nextElement = p;
		p->nextElement = currentElement;
		currentElement = p;
	}

	void append(const E& data)
	{
		node<E>* k = new node<E>;
		k->data = data;
		k->nextElement = NULL;
		if(sizeofList==0)
		{
			firstElement = k;
			currentElement = k;
			lastElement = k;
			sizeofList++;
			currentLocation = 1;
		}
		else {
			lastElement->nextElement = k;
			lastElement = k;
			sizeofList++;
		}
	}

	E remove()
	{
		node<E>*rmv = new node<E>;
		E removed{ currentElement->data};
		rmv = firstElement;
		int lo{ 1 };
		while (lo++ < currentLocation-1)
		{
			rmv = rmv->nextElement;
		}
		if (sizeofList == 1)
		{
			currentElement = firstElement = lastElement = NULL;
			sizeofList = 0;
			currentLocation = 0;
		}
		else if (currentLocation==1 && sizeofList!=1) {
			firstElement = currentElement->nextElement;
			currentElement = firstElement;
			sizeofList--;
		}
		else {
			rmv->nextElement = currentElement->nextElement;
			currentElement=rmv->nextElement;
			sizeofList--;
		}
		if (currentLocation == sizeofList + 1) {
			setToNewLocation(currentLocation - 1);
		}
		return removed;
	}

	void setListLocationToStart()
	{
		setToNewLocation(1);
	}

	void setListLocationToEnd()
	{
		setToNewLocation(sizeofList);
	}

	void previousElement()
	{
		setToNewLocation(currentLocation - 1);
	}

	void nextElement()
	{
		setToNewLocation(currentLocation + 1);
	}

	int setToNewLocation(int location)
	{
		currentLocation = location;
		int i{ 1 };
		currentElement = firstElement;
		while (i++ < currentLocation)
		{
			currentElement = currentElement->nextElement;
		}
		return currentLocation;
	}

	void print()
	{
		if (sizeofList == 0)
		{
			cout << "\nLinked List has no nodes, it's empty" << endl;
		}
		else {
			node<E>* pr = new node<E>;
			pr = firstElement;
			int i{ sizeofList };
			cout << " Linked List is :";
			while (i-->0)
			{
				cout << pr->data << " ";
				pr = pr->nextElement;
			}
		}
		cout << "\n\n";
	}

};

int main()
{
	linkList<int> L;

	do {
		int operation{ 0 };
		cout << "\n*******Enter number according to operation you want to perform:\n\n";

		cout << "    0-EXIT\n    1-Size of List\n    2-Current Location-\n    3-Data of current Location\n"
			"    4-Clear all the data from the list\n    5-Insert at current Location\n"
			"    6-Append\n    7-remove current Location Node data\n    8-Set current Location to the starting of list"
			"\n    9-Set current Location to the ending of list\n    10-Set current Location to Previous element"
			"\n    11-Set current Location to next element\n    12-set Location to input Location"
			"\n    13-Print Linked List\n\n********************"
			"********************************************\n\n";
		cout << "Attention!! Linked List index starts from 1 in this code\n";
		cout << "\nChoice Operation:";
		cin >> operation;
		switch (operation)
		{

		case 0: {
			return 0;
		}
		case 1: {
			cout << "\nSize of List:" << L.NumberOfElements() << "\n";
			break;
		}

		case 2: {
			if (L.firstElement == NULL)
			{
				cout << "\nLinked List is empty, NO DATA\n";
				break;
			}
			cout << L.CurrentLocation() << endl;
			break;
		}

		case 3: {
			if (L.firstElement == NULL)
			{
				cout << "\nLinked List is empty, NO DATA\n";
				break;
			}
			if (L.currentLocation > L.sizeofList)
			{
				cout << "\nNO data at that location\n";
				break;
			}
			cout << "\nCurrent Element Data is:" << L.getData() << endl;
			L.print();
			break;
		}

		case 4: {
			if (L.firstElement == NULL)
			{
				cout << "\nLinked List is already empty:\n";
				break;
			}
			L.clear();
			cout << " \n \"Every data is cleared\" \n ";
			break;
		}

		case 5: {
			cout << "\nEnter element you want to insert:";
			int data{ 0 };
			cin >> data;
			L.insert(data);
			cout << "\nNode Inserted\n\n";
			L.print();
			break;
		}

		case 6: {
			cout << "\nEnter data of node you want to append: \n";
			int dataa;
			cin >> dataa;
			L.append(dataa);
			cout << "\nNode Appended\n\n";
			L.print();
			break;
		}

		case 7: {
			if (L.sizeofList == 0 || L.currentLocation<0)
			{
				cout << "\nLinked List is empty you can not remove further\n";
				break;
			}
			cout<<"\nNode of data "<<L.remove()<<" is removed.\n"<<endl;
			L.print();
			break;
		}

		case 8: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			L.setListLocationToStart();
			break;
		}

		case 9: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			L.setListLocationToEnd();
			break;
		}

		case 10: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			if (L.currentLocation == 1 || L.currentLocation==0)
			{
				cout << "\nNO previous node present in Linked list\n";
				break;
			}
			L.previousElement();
			break;
		}
		case 11: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			if (L.currentLocation == L.sizeofList)
			{
				cout << "\nNo next node present in Linked list\n";
				break;
			}
			L.nextElement();
			break;
		}
		case 12: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			cout << "\nEnter Location you want to set:" << endl;
			int o{ 0 };
			do {
				cout << "\nEnter Valid Location i.e.,between:1 & "<<L.sizeofList<<endl;
				cin >> o;
			} while (o > L.sizeofList || o<=0);

			cout<<"\nCurrent location is set to "<<L.setToNewLocation(o);
			L.print();
			break;
		}
		case 13: {
			if (L.sizeofList == 0)
			{
				cout << "\nLinked List is empty\n";
				break;
			}
			L.print();
			break;
		}

		default:
			cout << "\nEnter valid number choice\n";
		}

	} while (1);
}