Linked List

#include <iostream>
#include <string>

#include "List.h"

//tail трябва да сочи към последният валиден елемент в списъка,
//или към nullptr ако списъкът е празен.

//Съответно head трябва винаги да сочи към първият елемент в списъка или към nullptr.

List::Node::Node(int value, Node * prev, Node * next) {
}

int List::Node::getValue() const {
    return this->value;
}
void List::Node::setValue(int value) {
    this->value = value;
}

//  Node * getNext() const;
List::Node* List::Node::getNext() const {
    return this->next;
}
void List::Node::setNext(Node * next) {
    this->next = next;
}

//   Node * getPrev() const;
List::Node* List::Node::getPrev() const {
    return this->prev;
}
void List::Node::setPrev(Node * prev) {
    this->prev = prev;
}

//Node * head;
//Node * tail;
//size_t size;

List::List() {    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV
    this->size = 0;
    this->head = nullptr;
    this->tail = nullptr;
}

List::List(const List& other) {  //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    if (other.head == nullptr) {
        this->head = nullptr;
        this->tail = nullptr;
        this->size = 0;
    }
    else {
        Node * currPtr = other.head;  //set to first link
        this->size = 0;
        this->head = nullptr;
        this->tail = nullptr;

        while (currPtr != nullptr) {
            //create a new Node to enter into the new List
            Node* newNode = new Node(currPtr->getValue(), nullptr, nullptr);
            //add newNode to new List
            if (this->size == 0) { //new list is empty
                this->head = this->tail = newNode;
            }
            else { //add newNode to end of new List
                this->tail->setNext(newNode);
                newNode->setPrev(this->tail);
                this->tail = this->tail->getNext();
            }
            this->size++;
            currPtr = currPtr->getNext();
        }
    }
}

int List::first() const {     //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV
    if (this->size > 0) {
        return this->head->getValue();  //head E на първи елемент !!!!!!!!!!!
    }
    else {
        return -1;
    }
}
void List::add(int value) {  //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV
    Node* newNode = new Node(value, nullptr, nullptr);
    if (this->size == 0) {
        this->head = newNode;
        this->tail = newNode;
    }
    else {
        this->tail->setNext(newNode);
        this->tail = this->tail->getNext();
    }
    this->size++;
}
void List::addAll(const List& other) {

}

void List::removeFirst() {    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
    if (this->size > 0) {
        Node *temp = this->head;
        this->head = temp->getNext();
        delete temp;
        temp = nullptr;
        this->size--;
    }
}
void List::removeAll() {
    while (this->size) {    // или while (!isEmpty())
        this->removeFirst();
        //this->size--;
    }
}

size_t List::getSize() const {   //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV
    return this->size;
}
bool List::isEmpty() const {   //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV
    return !(this->size);
}

List List::getReversed(List l) {
    //TO DO
    return l;
}

std::string List::toString() const {
    //TO DO
    std::string s;
    return s;
}

List& List::operator<<(const int& value) {  //!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVV

    Node* newNode = new Node(value, nullptr, nullptr);
    if (this->size == 0) {
        this->head = newNode;
        this->tail = newNode;
    }
    else {
        this->tail->setNext(newNode);
        this->tail = this->tail->getNext();
    }
    this->size++;
    return *this;
}
List& List::operator<<(const List& other) {
    //TO DO
    List l;
    return l;
}

List& List::operator=(const List& other) {    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVv
    //1.DeleteAll:
    Node * temp = this->head;
    Node  * prevPtr = nullptr;
    while (temp->getNext() != nullptr) {
        prevPtr = temp;
        temp = this->head->getNext();
        delete prevPtr;
        prevPtr = nullptr;
    }
    delete temp;
    temp = nullptr;
    this->head = nullptr;
    this->tail = nullptr;
    this->size = 0;

    //2.Copy
    Node * currPtr = other.head;  //set to first link
    while (currPtr != nullptr) {
        currPtr = currPtr->getNext(); // move to next link
    }
    this->head = currPtr;
    return *this;
}

List::~List() {    //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
    Node * temp = this->head;
    Node  * prevPtr = nullptr;
    while (temp->getNext() != nullptr) {
        prevPtr = temp;
        temp = this->head->getNext();
        delete prevPtr;
        prevPtr = nullptr;
    }
    delete temp;
    temp = nullptr;
    this->head = nullptr;
    this->tail = nullptr;
    this->size = 0;
    //ИЛИ:
    //this->removeAll();
}