// See at GitHu //https://github.com/kha333n/Doubly-Linked--List //on sololearn. Giving error #include using namespace std; #pragma once template class node { private: T object; node * nextNode; node * prevNode; public: T get(); void set(T object); node *getNext(); void setNext(node *nextNode); node *getPrev(); void setPrev(node *prevNode); }; template inline T node::get() { return object; } template void node::set(T object) { this -> object = object; } template node* node::getNext() { return nextNode; } template void node::setNext(node* nextNode) { this -> nextNode = nextNode; } template node* node::getPrev() { return prevNode; } template void node::setPrev(node* prevNode) { this -> prevNode = prevNode; } //#pragma once //#include "node.h" template class List { private: node *headNode; node *currentNode; node *prevNode; int size; public: List(); void add(T addObject); T get(); bool next(); bool previous(); void start(); void remove(); int length() const; }; //#include "List.h" //using namespace std; template List::List() //Default constructor. { headNode = new node(); //Creates a new node and store its address in headNode. headNode->setNext(0); //In the node created above stores the pointer value NULL or 0. currentNode = 0; prevNode = 0; //currentNode and PrevNode are also has NULL pointer. size = 0; //Size of list is 0. } template void List::add(T addObject) { node *newNode = new node(); //To add a node in list first create new node. newNode->set(addObject); //Insert the given value in the node. if (currentNode != 0) //If the pointer currentNode is not NULL or list is not empty then. { newNode->setNext(currentNode->getNext()); //Insert the value of next node in the pointer of newNode. So that it points to the next node if any in the list. newNode->setPrev(currentNode); //Points prevNode to the previous node. ( currentNode->getNext() ) -> setPrev(newNode); //Set nex nodes Prev pointer to the new node. currentNode->setNext(newNode); //Point the current pointer to the newNode currentNode = newNode; //Insert this new node in the currentNode } else //if the list is empty and creating its first node. { newNode->setNext(0); //There is no node after this node therefore next pointer of this node is NULL headNode->setNext(newNode); //This is first node, therefore it is head of list. newNode->setPrev(0); //No node before this, therefore we also pointed lastCurrentNode to headNode. currentNode = newNode; //CurrentNode pointer is also here. } size++; //increase the size of the list. } template T List::get() { // TODO: Add your implementation code here. if (currentNode != 0) //If currentNode is not at the last node in the list or list is not empty. { return currentNode->get(); //Return the value in the node where the currentNode pointer is. } return false; //Otherwise return false. } template bool List::next() { // TODO: Add your implementation code here. if (currentNode == 0) //If currentNode is on the last node in the list. { return false; } currentNode = currentNode->getNext(); //Point the currentNode pointer to the next node in the list. if (currentNode == 0 || size == 0) //If currentNode is on the last node or list is empty. { return false; } else { return true; //When next command success. return true. } } template bool List::previous() { if (currentNode == 0) //If currentNode is on the last node in the list. { return false; } currentNode = currentNode->getPrev(); if (currentNode == 0 || size == 0) //If currentNode is on the last node or list is empty. { return false; } else { return true; //When next command success. return true. } } template void List::start() //Points the pointers to the start of the list. { // TODO: Add your implementation code here. currentNode = headNode; } template void List::remove() { // TODO: Add your implementation code here. if (currentNode != 0 && currentNode != headNode) { ( currentNode->getPrev() ) -> setNext( currentNode->getNext() ); ( currentNode ->getNext() ) -> setPrev( currentNode->getPrev() ); currentNode = currentNode->getNext(); delete currentNode; size--; //Decrease the size of list. } } template int List::length() const { // TODO: Add your implementation code here. return size; //returns the length of the list. } // Doubly-Linked List.cpp : This file contains the 'main' function. Program execution begins and ends there. // //#include //#include "List.cpp" //using namespace std; int main() { List l1; l1.add(5); l1.add(6); l1.add(7); l1.previous(); l1.remove(); l1.add(8); l1.start(); while (l1.next()) { cout << l1.get() << endl; } while (l1.previous()) { cout << l1.get() << endl; } cout << l1.length() << endl; return 0; } // Run program: Ctrl + F5 or Debug > Start Without Debugging menu // Debug program: F5 or Debug > Start Debugging menu // Tips for Getting Started: // 1. Use the Solution Explorer window to add/manage files // 2. Use the Team Explorer window to connect to source control // 3. Use the Output window to see build output and other messages // 4. Use the Error List window to view errors // 5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project // 6. In the future, to open this project again, go to File > Open > Project and select the .sln file